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V5 [PATCH 1/2] x86: Move x86 processor cache info to cpu_features

Message ID CAMe9rOrBqfaU5-Goi=Zu6ZCtCCE0ERMuoVWDjCpQjOR9eyHQ=Q@mail.gmail.com
State Committed
Headers show
Series V5 [PATCH 1/2] x86: Move x86 processor cache info to cpu_features | expand

Commit Message

H.J. Lu Jan. 14, 2021, 7:28 p.m. UTC
On Thu, Jan 14, 2021 at 6:13 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 31/10/2020 12:44, H.J. Lu via Libc-alpha wrote:
> > 1. Move x86 processor cache info to _dl_x86_cpu_features in ld.so.
> > 2. Update tunable bounds with TUNABLE_SET_WITH_BOUNDS.
> > 3. Move x86 cache info initialization to dl-cacheinfo.h and initialize
> > x86 cache info in init_cpu_features ().
> > 4. Put x86 cache info for libc in cacheinfo.h, which is included in
> > libc-start.c in libc.a and is included in cacheinfo.c in libc.so.
>
> Patch looks ok for 2.33 with a small nit below regarding an implicit check.
>
> I have checked with some build variations (default and static-pie)
> and it shows no regression. I saw that --enable-tunables=no is not
> building anymore, but it is due another patch.
>
> Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
>
> > ---
> >  sysdeps/x86/cacheinfo.c            |  46 ++-
> >  sysdeps/x86/cacheinfo.h            | 400 ++-----------------------
> >  sysdeps/x86/cpu-features.c         |  35 +--
> >  sysdeps/x86/dl-cacheinfo.h         | 460 +++++++++++++++++++++++++++++
> >  sysdeps/x86/include/cpu-features.h |  22 ++
> >  5 files changed, 551 insertions(+), 412 deletions(-)
> >
> > diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
> > index 0d2fe3a2fa..e1ea4d5228 100644
> > --- a/sysdeps/x86/cacheinfo.c
> > +++ b/sysdeps/x86/cacheinfo.c
> > @@ -18,11 +18,8 @@
> >
> >  #if IS_IN (libc)
> >
> > -#include <assert.h>
> >  #include <unistd.h>
> > -#include <cpuid.h>
> >  #include <ldsodefs.h>
> > -#include <dl-cacheinfo.h>
> >
> >  /* Get the value of the system variable NAME.  */
> >  long int
> > @@ -30,20 +27,45 @@ attribute_hidden
> >  __cache_sysconf (int name)
> >  {
> >    const struct cpu_features *cpu_features = __get_cpu_features ();
> > +  switch (name)
> > +    {
> > +    case _SC_LEVEL1_ICACHE_SIZE:
> > +      return cpu_features->level1_icache_size;
> >
> > -  if (cpu_features->basic.kind == arch_kind_intel)
> > -    return handle_intel (name, cpu_features);
> > +    case _SC_LEVEL1_DCACHE_SIZE:
> > +      return cpu_features->level1_dcache_size;
> >
> > -  if (cpu_features->basic.kind == arch_kind_amd)
> > -    return handle_amd (name);
> > +    case _SC_LEVEL1_DCACHE_ASSOC:
> > +      return cpu_features->level1_dcache_assoc;
> >
> > -  if (cpu_features->basic.kind == arch_kind_zhaoxin)
> > -    return handle_zhaoxin (name);
> > +    case _SC_LEVEL1_DCACHE_LINESIZE:
> > +      return cpu_features->level1_dcache_linesize;
> >
> > -  // XXX Fill in more vendors.
> > +    case _SC_LEVEL2_CACHE_SIZE:
> > +      return cpu_features->level2_cache_size;
> >
> > -  /* CPU not known, we have no information.  */
> > -  return 0;
> > +    case _SC_LEVEL2_CACHE_ASSOC:
> > +      return cpu_features->level2_cache_assoc;
> > +
> > +    case _SC_LEVEL2_CACHE_LINESIZE:
> > +      return cpu_features->level2_cache_linesize;
> > +
> > +    case _SC_LEVEL3_CACHE_SIZE:
> > +      return cpu_features->level3_cache_size;
> > +
> > +    case _SC_LEVEL3_CACHE_ASSOC:
> > +      return cpu_features->level3_cache_assoc;
> > +
> > +    case _SC_LEVEL3_CACHE_LINESIZE:
> > +      return cpu_features->level3_cache_linesize;
> > +
> > +    case _SC_LEVEL4_CACHE_SIZE:
> > +      return cpu_features->level4_cache_size;
> > +
> > +    default:
> > +      break;
> > +    }
> > +  return -1;
> >  }
> >
> >  # ifdef SHARED
>
> Ok, so now it handles _SC_LEVEL1_ICACHE_SIZE <= name < _SC_LEVEL4_CACHE_LINESIZE
> and returns -1 otherwise.  It align with sysconf interface.
>
> > diff --git a/sysdeps/x86/cacheinfo.h b/sysdeps/x86/cacheinfo.h
> > index 0aec0e2875..5aa40b45b5 100644
> > --- a/sysdeps/x86/cacheinfo.h
> > +++ b/sysdeps/x86/cacheinfo.h
> > @@ -18,7 +18,16 @@
> >
> >  #include <assert.h>
> >  #include <unistd.h>
> > +#include <cpuid.h>
> > +#include <cpu-features.h>
> >
> > +#if HAVE_TUNABLES
> > +# define TUNABLE_NAMESPACE cpu
> > +# include <unistd.h>         /* Get STDOUT_FILENO for _dl_printf.  */
> > +# include <elf/dl-tunables.h>
> > +#endif
> > +
> > +#if IS_IN (libc)
> >  /* Data cache size for use in memory and string routines, typically
> >     L1 size, rounded to multiple of 256 bytes.  */
> >  long int __x86_data_cache_size_half attribute_hidden = 32 * 1024 / 2;
>
> Ok.
>
> > @@ -45,385 +54,30 @@ long int __x86_rep_movsb_threshold attribute_hidden = 2048;
> >  /* Threshold to use Enhanced REP STOSB.  */
> >  long int __x86_rep_stosb_threshold attribute_hidden = 2048;
> >
> > -static void
> > -get_common_cache_info (long int *shared_ptr, unsigned int *threads_ptr,
> > -                    long int core)
> > -{
> > -  unsigned int eax;
> > -  unsigned int ebx;
> > -  unsigned int ecx;
> > -  unsigned int edx;
> > -
> > -  /* Number of logical processors sharing L2 cache.  */
> > -  int threads_l2;
> > -
> > -  /* Number of logical processors sharing L3 cache.  */
> > -  int threads_l3;
> > -
> > -  const struct cpu_features *cpu_features = __get_cpu_features ();
> > -  int max_cpuid = cpu_features->basic.max_cpuid;
> > -  unsigned int family = cpu_features->basic.family;
> > -  unsigned int model = cpu_features->basic.model;
> > -  long int shared = *shared_ptr;
> > -  unsigned int threads = *threads_ptr;
> > -  bool inclusive_cache = true;
> > -  bool support_count_mask = true;
> > -
> > -  /* Try L3 first.  */
> > -  unsigned int level = 3;
> > -
> > -  if (cpu_features->basic.kind == arch_kind_zhaoxin && family == 6)
> > -    support_count_mask = false;
> > -
> > -  if (shared <= 0)
> > -    {
> > -      /* Try L2 otherwise.  */
> > -      level  = 2;
> > -      shared = core;
> > -      threads_l2 = 0;
> > -      threads_l3 = -1;
> > -    }
> > -  else
> > -    {
> > -      threads_l2 = 0;
> > -      threads_l3 = 0;
> > -    }
> > -
> > -  /* A value of 0 for the HTT bit indicates there is only a single
> > -     logical processor.  */
> > -  if (HAS_CPU_FEATURE (HTT))
> > -    {
> > -      /* Figure out the number of logical threads that share the
> > -         highest cache level.  */
> > -      if (max_cpuid >= 4)
> > -        {
> > -          int i = 0;
> > -
> > -          /* Query until cache level 2 and 3 are enumerated.  */
> > -          int check = 0x1 | (threads_l3 == 0) << 1;
> > -          do
> > -            {
> > -              __cpuid_count (4, i++, eax, ebx, ecx, edx);
> > -
> > -              /* There seems to be a bug in at least some Pentium Ds
> > -                 which sometimes fail to iterate all cache parameters.
> > -                 Do not loop indefinitely here, stop in this case and
> > -                 assume there is no such information.  */
> > -              if (cpu_features->basic.kind == arch_kind_intel
> > -                  && (eax & 0x1f) == 0 )
> > -                goto intel_bug_no_cache_info;
> > -
> > -              switch ((eax >> 5) & 0x7)
> > -                {
> > -                  default:
> > -                    break;
> > -                  case 2:
> > -                    if ((check & 0x1))
> > -                      {
> > -                        /* Get maximum number of logical processors
> > -                           sharing L2 cache.  */
> > -                        threads_l2 = (eax >> 14) & 0x3ff;
> > -                        check &= ~0x1;
> > -                      }
> > -                    break;
> > -                  case 3:
> > -                    if ((check & (0x1 << 1)))
> > -                      {
> > -                        /* Get maximum number of logical processors
> > -                           sharing L3 cache.  */
> > -                        threads_l3 = (eax >> 14) & 0x3ff;
> > -
> > -                        /* Check if L2 and L3 caches are inclusive.  */
> > -                        inclusive_cache = (edx & 0x2) != 0;
> > -                        check &= ~(0x1 << 1);
> > -                      }
> > -                    break;
> > -                }
> > -            }
> > -          while (check);
> > -
> > -          /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
> > -             numbers of addressable IDs for logical processors sharing
> > -             the cache, instead of the maximum number of threads
> > -             sharing the cache.  */
> > -          if (max_cpuid >= 11 && support_count_mask)
> > -            {
> > -              /* Find the number of logical processors shipped in
> > -                 one core and apply count mask.  */
> > -              i = 0;
> > -
> > -              /* Count SMT only if there is L3 cache.  Always count
> > -                 core if there is no L3 cache.  */
> > -              int count = ((threads_l2 > 0 && level == 3)
> > -                           | ((threads_l3 > 0
> > -                               || (threads_l2 > 0 && level == 2)) << 1));
> > -
> > -              while (count)
> > -                {
> > -                  __cpuid_count (11, i++, eax, ebx, ecx, edx);
> > -
> > -                  int shipped = ebx & 0xff;
> > -                  int type = ecx & 0xff00;
> > -                  if (shipped == 0 || type == 0)
> > -                    break;
> > -                  else if (type == 0x100)
> > -                    {
> > -                      /* Count SMT.  */
> > -                      if ((count & 0x1))
> > -                        {
> > -                          int count_mask;
> > -
> > -                          /* Compute count mask.  */
> > -                          asm ("bsr %1, %0"
> > -                               : "=r" (count_mask) : "g" (threads_l2));
> > -                          count_mask = ~(-1 << (count_mask + 1));
> > -                          threads_l2 = (shipped - 1) & count_mask;
> > -                          count &= ~0x1;
> > -                        }
> > -                    }
> > -                  else if (type == 0x200)
> > -                    {
> > -                      /* Count core.  */
> > -                      if ((count & (0x1 << 1)))
> > -                        {
> > -                          int count_mask;
> > -                          int threads_core
> > -                            = (level == 2 ? threads_l2 : threads_l3);
> > -
> > -                          /* Compute count mask.  */
> > -                          asm ("bsr %1, %0"
> > -                               : "=r" (count_mask) : "g" (threads_core));
> > -                          count_mask = ~(-1 << (count_mask + 1));
> > -                          threads_core = (shipped - 1) & count_mask;
> > -                          if (level == 2)
> > -                            threads_l2 = threads_core;
> > -                          else
> > -                            threads_l3 = threads_core;
> > -                          count &= ~(0x1 << 1);
> > -                        }
> > -                    }
> > -                }
> > -            }
> > -          if (threads_l2 > 0)
> > -            threads_l2 += 1;
> > -          if (threads_l3 > 0)
> > -            threads_l3 += 1;
> > -          if (level == 2)
> > -            {
> > -              if (threads_l2)
> > -                {
> > -                  threads = threads_l2;
> > -                  if (cpu_features->basic.kind == arch_kind_intel
> > -                      && threads > 2
> > -                      && family == 6)
> > -                    switch (model)
> > -                      {
> > -                        case 0x37:
> > -                        case 0x4a:
> > -                        case 0x4d:
> > -                        case 0x5a:
> > -                        case 0x5d:
> > -                          /* Silvermont has L2 cache shared by 2 cores.  */
> > -                          threads = 2;
> > -                          break;
> > -                        default:
> > -                          break;
> > -                      }
> > -                }
> > -            }
> > -          else if (threads_l3)
> > -            threads = threads_l3;
> > -        }
> > -      else
> > -        {
> > -intel_bug_no_cache_info:
> > -          /* Assume that all logical threads share the highest cache
> > -             level.  */
> > -          threads
> > -            = ((cpu_features->features[COMMON_CPUID_INDEX_1].cpuid.ebx
> > -                >> 16) & 0xff);
> > -        }
> > -
> > -        /* Cap usage of highest cache level to the number of supported
> > -           threads.  */
> > -        if (shared > 0 && threads > 0)
> > -          shared /= threads;
> > -    }
> > -
> > -  /* Account for non-inclusive L2 and L3 caches.  */
> > -  if (!inclusive_cache)
> > -    {
> > -      if (threads_l2 > 0)
> > -        core /= threads_l2;
> > -      shared += core;
> > -    }
> > -
> > -  *shared_ptr = shared;
> > -  *threads_ptr = threads;
> > -}
> > -
> >  static void
> >  init_cacheinfo (void)
> >  {
> > -  /* Find out what brand of processor.  */
> > -  unsigned int ebx;
> > -  unsigned int ecx;
> > -  unsigned int edx;
> > -  int max_cpuid_ex;
> > -  long int data = -1;
> > -  long int shared = -1;
> > -  long int core;
> > -  unsigned int threads = 0;
> >    const struct cpu_features *cpu_features = __get_cpu_features ();
> > +  long int data = cpu_features->data_cache_size;
> > +  __x86_raw_data_cache_size_half = data / 2;
> > +  __x86_raw_data_cache_size = data;
> > +  /* Round data cache size to multiple of 256 bytes.  */
> > +  data = data & ~255L;
> > +  __x86_data_cache_size_half = data / 2;
> > +  __x86_data_cache_size = data;
> > +
> > +  long int shared = cpu_features->shared_cache_size;
> > +  __x86_raw_shared_cache_size_half = shared / 2;
> > +  __x86_raw_shared_cache_size = shared;
> > +  /* Round shared cache size to multiple of 256 bytes.  */
> > +  shared = shared & ~255L;
> > +  __x86_shared_cache_size_half = shared / 2;
> > +  __x86_shared_cache_size = shared;
> >
> > -  /* NB: In libc.so, cpu_features is defined in ld.so and is initialized
> > -     by DL_PLATFORM_INIT or IFUNC relocation before init_cacheinfo is
> > -     called by IFUNC relocation.  In libc.a, init_cacheinfo is called
> > -     from init_cpu_features by ARCH_INIT_CPU_FEATURES.  */
> > -  assert (cpu_features->basic.kind != arch_kind_unknown);
> > -
> > -  if (cpu_features->basic.kind == arch_kind_intel)
> > -    {
> > -      data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, cpu_features);
> > -      core = handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
> > -      shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, cpu_features);
> > -
> > -      get_common_cache_info (&shared, &threads, core);
> > -    }
> > -  else if (cpu_features->basic.kind == arch_kind_zhaoxin)
> > -    {
> > -      data = handle_zhaoxin (_SC_LEVEL1_DCACHE_SIZE);
> > -      core = handle_zhaoxin (_SC_LEVEL2_CACHE_SIZE);
> > -      shared = handle_zhaoxin (_SC_LEVEL3_CACHE_SIZE);
> > -
> > -      get_common_cache_info (&shared, &threads, core);
> > -    }
> > -  else if (cpu_features->basic.kind == arch_kind_amd)
> > -    {
> > -      data   = handle_amd (_SC_LEVEL1_DCACHE_SIZE);
> > -      long int core = handle_amd (_SC_LEVEL2_CACHE_SIZE);
> > -      shared = handle_amd (_SC_LEVEL3_CACHE_SIZE);
> > -
> > -      /* Get maximum extended function. */
> > -      __cpuid (0x80000000, max_cpuid_ex, ebx, ecx, edx);
> > -
> > -      if (shared <= 0)
> > -     /* No shared L3 cache.  All we have is the L2 cache.  */
> > -     shared = core;
> > -      else
> > -     {
> > -       /* Figure out the number of logical threads that share L3.  */
> > -       if (max_cpuid_ex >= 0x80000008)
> > -         {
> > -           /* Get width of APIC ID.  */
> > -           __cpuid (0x80000008, max_cpuid_ex, ebx, ecx, edx);
> > -           threads = 1 << ((ecx >> 12) & 0x0f);
> > -         }
> > -
> > -       if (threads == 0 || cpu_features->basic.family >= 0x17)
> > -         {
> > -           /* If APIC ID width is not available, use logical
> > -              processor count.  */
> > -           __cpuid (0x00000001, max_cpuid_ex, ebx, ecx, edx);
> > -
> > -           if ((edx & (1 << 28)) != 0)
> > -             threads = (ebx >> 16) & 0xff;
> > -         }
> > -
> > -       /* Cap usage of highest cache level to the number of
> > -          supported threads.  */
> > -       if (threads > 0)
> > -         shared /= threads;
> > -
> > -       /* Get shared cache per ccx for Zen architectures.  */
> > -       if (cpu_features->basic.family >= 0x17)
> > -         {
> > -           unsigned int eax;
> > -
> > -           /* Get number of threads share the L3 cache in CCX.  */
> > -           __cpuid_count (0x8000001D, 0x3, eax, ebx, ecx, edx);
> > -
> > -           unsigned int threads_per_ccx = ((eax >> 14) & 0xfff) + 1;
> > -           shared *= threads_per_ccx;
> > -         }
> > -       else
> > -         {
> > -           /* Account for exclusive L2 and L3 caches.  */
> > -           shared += core;
> > -            }
> > -      }
> > -    }
> > -
> > -  /* Prefer cache size configure via tuning.  */
> > -  if (cpu_features->data_cache_size != 0)
> > -    data = cpu_features->data_cache_size;
> > -
> > -  if (data > 0)
> > -    {
> > -      __x86_raw_data_cache_size_half = data / 2;
> > -      __x86_raw_data_cache_size = data;
> > -      /* Round data cache size to multiple of 256 bytes.  */
> > -      data = data & ~255L;
> > -      __x86_data_cache_size_half = data / 2;
> > -      __x86_data_cache_size = data;
> > -    }
> > -
> > -  /* Prefer cache size configure via tuning.  */
> > -  if (cpu_features->shared_cache_size != 0)
> > -    shared = cpu_features->shared_cache_size;
> > -
> > -  if (shared > 0)
> > -    {
> > -      __x86_raw_shared_cache_size_half = shared / 2;
> > -      __x86_raw_shared_cache_size = shared;
> > -      /* Round shared cache size to multiple of 256 bytes.  */
> > -      shared = shared & ~255L;
> > -      __x86_shared_cache_size_half = shared / 2;
> > -      __x86_shared_cache_size = shared;
> > -    }
> > -
> > -  /* The default setting for the non_temporal threshold is 3/4 of one
> > -     thread's share of the chip's cache. For most Intel and AMD processors
> > -     with an initial release date between 2017 and 2020, a thread's typical
> > -     share of the cache is from 500 KBytes to 2 MBytes. Using the 3/4
> > -     threshold leaves 125 KBytes to 500 KBytes of the thread's data
> > -     in cache after a maximum temporal copy, which will maintain
> > -     in cache a reasonable portion of the thread's stack and other
> > -     active data. If the threshold is set higher than one thread's
> > -     share of the cache, it has a substantial risk of negatively
> > -     impacting the performance of other threads running on the chip. */
> >    __x86_shared_non_temporal_threshold
> > -    = (cpu_features->non_temporal_threshold != 0
> > -       ? cpu_features->non_temporal_threshold
> > -       : __x86_shared_cache_size * 3 / 4);
> > -
> > -  /* NB: The REP MOVSB threshold must be greater than VEC_SIZE * 8.  */
> > -  unsigned int minimum_rep_movsb_threshold;
> > -  /* NB: The default REP MOVSB threshold is 2048 * (VEC_SIZE / 16).  */
> > -  unsigned int rep_movsb_threshold;
> > -  if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> > -      && !CPU_FEATURE_PREFERRED_P (cpu_features, Prefer_No_AVX512))
> > -    {
> > -      rep_movsb_threshold = 2048 * (64 / 16);
> > -      minimum_rep_movsb_threshold = 64 * 8;
> > -    }
> > -  else if (CPU_FEATURE_PREFERRED_P (cpu_features,
> > -                                 AVX_Fast_Unaligned_Load))
> > -    {
> > -      rep_movsb_threshold = 2048 * (32 / 16);
> > -      minimum_rep_movsb_threshold = 32 * 8;
> > -    }
> > -  else
> > -    {
> > -      rep_movsb_threshold = 2048 * (16 / 16);
> > -      minimum_rep_movsb_threshold = 16 * 8;
> > -    }
> > -  if (cpu_features->rep_movsb_threshold > minimum_rep_movsb_threshold)
> > -    __x86_rep_movsb_threshold = cpu_features->rep_movsb_threshold;
> > -  else
> > -    __x86_rep_movsb_threshold = rep_movsb_threshold;
> > +    = cpu_features->non_temporal_threshold;
> >
> > -# if HAVE_TUNABLES
> > +  __x86_rep_movsb_threshold = cpu_features->rep_movsb_threshold;
> >    __x86_rep_stosb_threshold = cpu_features->rep_stosb_threshold;
> > -# endif
> >  }
> > +#endif
>
> Ok, it is refactoring the code.
>
> > diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
> > index f26deba38d..51c12d89ca 100644
> > --- a/sysdeps/x86/cpu-features.c
> > +++ b/sysdeps/x86/cpu-features.c
> > @@ -16,21 +16,12 @@
> >     License along with the GNU C Library; if not, see
> >     <https://www.gnu.org/licenses/>.  */
> >
> > -#include <cpuid.h>
> >  #include <dl-hwcap.h>
> >  #include <libc-pointer-arith.h>
> > -#if IS_IN (libc) && !defined SHARED
> > -# include <assert.h>
> > -# include <unistd.h>
> > -# include <dl-cacheinfo.h>
> > -# include <cacheinfo.h>
> > -#endif
> > +#include <cacheinfo.h>
> > +#include <dl-cacheinfo.h>
> >
> >  #if HAVE_TUNABLES
> > -# define TUNABLE_NAMESPACE cpu
> > -# include <unistd.h>         /* Get STDOUT_FILENO for _dl_printf.  */
> > -# include <elf/dl-tunables.h>
> > -
> >  extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *)
> >    attribute_hidden;
> >
>
> Ok.
>
> > @@ -642,24 +633,14 @@ no_cpuid:
> >    cpu_features->basic.model = model;
> >    cpu_features->basic.stepping = stepping;
> >
> > +  dl_init_cacheinfo (cpu_features);
> > +
> >  #if HAVE_TUNABLES
> >    TUNABLE_GET (hwcaps, tunable_val_t *, TUNABLE_CALLBACK (set_hwcaps));
> > -  cpu_features->non_temporal_threshold
> > -    = TUNABLE_GET (x86_non_temporal_threshold, long int, NULL);
> > -  cpu_features->rep_movsb_threshold
> > -    = TUNABLE_GET (x86_rep_movsb_threshold, long int, NULL);
> > -  cpu_features->rep_stosb_threshold
> > -    = TUNABLE_GET (x86_rep_stosb_threshold, long int, NULL);
> > -  cpu_features->data_cache_size
> > -    = TUNABLE_GET (x86_data_cache_size, long int, NULL);
> > -  cpu_features->shared_cache_size
> > -    = TUNABLE_GET (x86_shared_cache_size, long int, NULL);
> > -#endif
> > -
> > -  /* Reuse dl_platform, dl_hwcap and dl_hwcap_mask for x86.  */
> > -#if !HAVE_TUNABLES && defined SHARED
> > -  /* The glibc.cpu.hwcap_mask tunable is initialized already, so no need to do
> > -     this.  */
> > +#elif defined SHARED
> > +  /* Reuse dl_platform, dl_hwcap and dl_hwcap_mask for x86.  The
> > +     glibc.cpu.hwcap_mask tunable is initialized already, so no
> > +     need to do this.  */
> >    GLRO(dl_hwcap_mask) = HWCAP_IMPORTANT;
> >  #endif
> >
>
> Ok.
>
> > diff --git a/sysdeps/x86/dl-cacheinfo.h b/sysdeps/x86/dl-cacheinfo.h
> > index b2b90074b0..9632ee7818 100644
> > --- a/sysdeps/x86/dl-cacheinfo.h
> > +++ b/sysdeps/x86/dl-cacheinfo.h
> > @@ -476,3 +476,463 @@ handle_zhaoxin (int name)
> >    /* Nothing found.  */
> >    return 0;
> >  }
> > +
> > +static void
> > +get_common_cache_info (long int *shared_ptr, unsigned int *threads_ptr,
> > +                long int core)
> > +{
> > +  unsigned int eax;
> > +  unsigned int ebx;
> > +  unsigned int ecx;
> > +  unsigned int edx;
> > +
> > +  /* Number of logical processors sharing L2 cache.  */
> > +  int threads_l2;
> > +
> > +  /* Number of logical processors sharing L3 cache.  */
> > +  int threads_l3;
> > +
> > +  const struct cpu_features *cpu_features = __get_cpu_features ();
> > +  int max_cpuid = cpu_features->basic.max_cpuid;
> > +  unsigned int family = cpu_features->basic.family;
> > +  unsigned int model = cpu_features->basic.model;
> > +  long int shared = *shared_ptr;
> > +  unsigned int threads = *threads_ptr;
> > +  bool inclusive_cache = true;
> > +  bool support_count_mask = true;
> > +
> > +  /* Try L3 first.  */
> > +  unsigned int level = 3;
> > +
> > +  if (cpu_features->basic.kind == arch_kind_zhaoxin && family == 6)
> > +    support_count_mask = false;
> > +
> > +  if (shared <= 0)
> > +    {
> > +      /* Try L2 otherwise.  */
> > +      level  = 2;
> > +      shared = core;
> > +      threads_l2 = 0;
> > +      threads_l3 = -1;
> > +    }
> > +  else
> > +    {
> > +      threads_l2 = 0;
> > +      threads_l3 = 0;
> > +    }
> > +
> > +  /* A value of 0 for the HTT bit indicates there is only a single
> > +     logical processor.  */
> > +  if (HAS_CPU_FEATURE (HTT))
> > +    {
> > +      /* Figure out the number of logical threads that share the
> > +         highest cache level.  */
> > +      if (max_cpuid >= 4)
> > +        {
> > +          int i = 0;
> > +
> > +          /* Query until cache level 2 and 3 are enumerated.  */
> > +          int check = 0x1 | (threads_l3 == 0) << 1;
> > +          do
> > +            {
> > +              __cpuid_count (4, i++, eax, ebx, ecx, edx);
> > +
> > +              /* There seems to be a bug in at least some Pentium Ds
> > +                 which sometimes fail to iterate all cache parameters.
> > +                 Do not loop indefinitely here, stop in this case and
> > +                 assume there is no such information.  */
> > +              if (cpu_features->basic.kind == arch_kind_intel
> > +                  && (eax & 0x1f) == 0 )
> > +                goto intel_bug_no_cache_info;
> > +
> > +              switch ((eax >> 5) & 0x7)
> > +                {
> > +                  default:
> > +                    break;
> > +                  case 2:
> > +                    if ((check & 0x1))
> > +                      {
> > +                        /* Get maximum number of logical processors
> > +                           sharing L2 cache.  */
> > +                        threads_l2 = (eax >> 14) & 0x3ff;
> > +                        check &= ~0x1;
> > +                      }
> > +                    break;
> > +                  case 3:
> > +                    if ((check & (0x1 << 1)))
> > +                      {
> > +                        /* Get maximum number of logical processors
> > +                           sharing L3 cache.  */
> > +                        threads_l3 = (eax >> 14) & 0x3ff;
> > +
> > +                        /* Check if L2 and L3 caches are inclusive.  */
> > +                        inclusive_cache = (edx & 0x2) != 0;
> > +                        check &= ~(0x1 << 1);
> > +                      }
> > +                    break;
> > +                }
> > +            }
> > +          while (check);
> > +
> > +          /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
> > +             numbers of addressable IDs for logical processors sharing
> > +             the cache, instead of the maximum number of threads
> > +             sharing the cache.  */
> > +          if (max_cpuid >= 11 && support_count_mask)
> > +            {
> > +              /* Find the number of logical processors shipped in
> > +                 one core and apply count mask.  */
> > +              i = 0;
> > +
> > +              /* Count SMT only if there is L3 cache.  Always count
> > +                 core if there is no L3 cache.  */
> > +              int count = ((threads_l2 > 0 && level == 3)
> > +                           | ((threads_l3 > 0
> > +                               || (threads_l2 > 0 && level == 2)) << 1));
> > +
> > +              while (count)
> > +                {
> > +                  __cpuid_count (11, i++, eax, ebx, ecx, edx);
> > +
> > +                  int shipped = ebx & 0xff;
> > +                  int type = ecx & 0xff00;
> > +                  if (shipped == 0 || type == 0)
> > +                    break;
> > +                  else if (type == 0x100)
> > +                    {
> > +                      /* Count SMT.  */
> > +                      if ((count & 0x1))
> > +                        {
> > +                          int count_mask;
> > +
> > +                          /* Compute count mask.  */
> > +                          asm ("bsr %1, %0"
> > +                               : "=r" (count_mask) : "g" (threads_l2));
> > +                          count_mask = ~(-1 << (count_mask + 1));
> > +                          threads_l2 = (shipped - 1) & count_mask;
> > +                          count &= ~0x1;
> > +                        }
> > +                    }
> > +                  else if (type == 0x200)
> > +                    {
> > +                      /* Count core.  */
> > +                      if ((count & (0x1 << 1)))
> > +                        {
> > +                          int count_mask;
> > +                          int threads_core
> > +                            = (level == 2 ? threads_l2 : threads_l3);
> > +
> > +                          /* Compute count mask.  */
> > +                          asm ("bsr %1, %0"
> > +                               : "=r" (count_mask) : "g" (threads_core));
> > +                          count_mask = ~(-1 << (count_mask + 1));
> > +                          threads_core = (shipped - 1) & count_mask;
> > +                          if (level == 2)
> > +                            threads_l2 = threads_core;
> > +                          else
> > +                            threads_l3 = threads_core;
> > +                          count &= ~(0x1 << 1);
> > +                        }
> > +                    }
> > +                }
> > +            }
> > +          if (threads_l2 > 0)
> > +            threads_l2 += 1;
> > +          if (threads_l3 > 0)
> > +            threads_l3 += 1;
> > +          if (level == 2)
> > +            {
> > +              if (threads_l2)
> > +                {
> > +                  threads = threads_l2;
> > +                  if (cpu_features->basic.kind == arch_kind_intel
> > +                      && threads > 2
> > +                      && family == 6)
> > +                    switch (model)
> > +                      {
> > +                        case 0x37:
> > +                        case 0x4a:
> > +                        case 0x4d:
> > +                        case 0x5a:
> > +                        case 0x5d:
> > +                          /* Silvermont has L2 cache shared by 2 cores.  */
> > +                          threads = 2;
> > +                          break;
> > +                        default:
> > +                          break;
> > +                      }
> > +                }
> > +            }
> > +          else if (threads_l3)
> > +            threads = threads_l3;
> > +        }
> > +      else
> > +        {
> > +intel_bug_no_cache_info:
> > +          /* Assume that all logical threads share the highest cache
> > +             level.  */
> > +          threads
> > +            = ((cpu_features->features[COMMON_CPUID_INDEX_1].cpuid.ebx
> > +                >> 16) & 0xff);
> > +        }
> > +
> > +        /* Cap usage of highest cache level to the number of supported
> > +           threads.  */
> > +        if (shared > 0 && threads > 0)
> > +          shared /= threads;
> > +    }
> > +
> > +  /* Account for non-inclusive L2 and L3 caches.  */
> > +  if (!inclusive_cache)
> > +    {
> > +      if (threads_l2 > 0)
> > +        core /= threads_l2;
> > +      shared += core;
> > +    }
> > +
> > +  *shared_ptr = shared;
> > +  *threads_ptr = threads;
> > +}
> > +
>
> Ok, so this is function moved from sysdeps/x86/cacheinfo.h.
>
> > +static void
> > +dl_init_cacheinfo (struct cpu_features *cpu_features)
> > +{
> > +  /* Find out what brand of processor.  */
> > +  unsigned int ebx;
> > +  unsigned int ecx;
> > +  unsigned int edx;
> > +  int max_cpuid_ex;
> > +  long int data = -1;
> > +  long int shared = -1;
> > +  long int core;
> > +  unsigned int threads = 0;
> > +  unsigned long int level1_icache_size = -1;
> > +  unsigned long int level1_dcache_size = -1;
> > +  unsigned long int level1_dcache_assoc = -1;
> > +  unsigned long int level1_dcache_linesize = -1;
> > +  unsigned long int level2_cache_size = -1;
> > +  unsigned long int level2_cache_assoc = -1;
> > +  unsigned long int level2_cache_linesize = -1;
> > +  unsigned long int level3_cache_size = -1;
> > +  unsigned long int level3_cache_assoc = -1;
> > +  unsigned long int level3_cache_linesize = -1;
> > +  unsigned long int level4_cache_size = -1;
> > +
> > +  if (cpu_features->basic.kind == arch_kind_intel)
> > +    {
> > +      data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, cpu_features);
> > +      core = handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
> > +      shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, cpu_features);
> > +
> > +      level1_icache_size
> > +     = handle_intel (_SC_LEVEL1_ICACHE_SIZE, cpu_features);
> > +      level1_dcache_size = data;
> > +      level1_dcache_assoc
> > +     = handle_intel (_SC_LEVEL1_DCACHE_ASSOC, cpu_features);
> > +      level1_dcache_linesize
> > +     = handle_intel (_SC_LEVEL1_DCACHE_LINESIZE, cpu_features);
> > +      level2_cache_size = core;
> > +      level2_cache_assoc
> > +     = handle_intel (_SC_LEVEL2_CACHE_ASSOC, cpu_features);
> > +      level2_cache_linesize
> > +     = handle_intel (_SC_LEVEL2_CACHE_LINESIZE, cpu_features);
> > +      level3_cache_size = shared;
> > +      level3_cache_assoc
> > +     = handle_intel (_SC_LEVEL3_CACHE_ASSOC, cpu_features);
> > +      level3_cache_linesize
> > +     = handle_intel (_SC_LEVEL3_CACHE_LINESIZE, cpu_features);
> > +      level4_cache_size
> > +     = handle_intel (_SC_LEVEL4_CACHE_SIZE, cpu_features);
> > +
> > +      get_common_cache_info (&shared, &threads, core);
> > +    }
> > +  else if (cpu_features->basic.kind == arch_kind_zhaoxin)
> > +    {
> > +      data = handle_zhaoxin (_SC_LEVEL1_DCACHE_SIZE);
> > +      core = handle_zhaoxin (_SC_LEVEL2_CACHE_SIZE);
> > +      shared = handle_zhaoxin (_SC_LEVEL3_CACHE_SIZE);
> > +
> > +      level1_icache_size = handle_zhaoxin (_SC_LEVEL1_ICACHE_SIZE);
> > +      level1_dcache_size = data;
> > +      level1_dcache_assoc = handle_zhaoxin (_SC_LEVEL1_DCACHE_ASSOC);
> > +      level1_dcache_linesize = handle_zhaoxin (_SC_LEVEL1_DCACHE_LINESIZE);
> > +      level2_cache_size = core;
> > +      level2_cache_assoc = handle_zhaoxin (_SC_LEVEL2_CACHE_ASSOC);
> > +      level2_cache_linesize = handle_zhaoxin (_SC_LEVEL2_CACHE_LINESIZE);
> > +      level3_cache_size = shared;
> > +      level3_cache_assoc = handle_zhaoxin (_SC_LEVEL3_CACHE_ASSOC);
> > +      level3_cache_linesize = handle_zhaoxin (_SC_LEVEL3_CACHE_LINESIZE);
> > +
> > +      get_common_cache_info (&shared, &threads, core);
> > +    }
> > +  else if (cpu_features->basic.kind == arch_kind_amd)
> > +    {
> > +      data  = handle_amd (_SC_LEVEL1_DCACHE_SIZE);
> > +      core = handle_amd (_SC_LEVEL2_CACHE_SIZE);
> > +      shared = handle_amd (_SC_LEVEL3_CACHE_SIZE);
> > +
> > +      level1_icache_size = handle_amd (_SC_LEVEL1_ICACHE_SIZE);
> > +      level1_dcache_size = data;
> > +      level1_dcache_assoc = handle_amd (_SC_LEVEL1_DCACHE_ASSOC);
> > +      level1_dcache_linesize = handle_amd (_SC_LEVEL1_DCACHE_LINESIZE);
> > +      level2_cache_size = core;
> > +      level2_cache_assoc = handle_amd (_SC_LEVEL2_CACHE_ASSOC);
> > +      level2_cache_linesize = handle_amd (_SC_LEVEL2_CACHE_LINESIZE);
> > +      level3_cache_size = shared;
> > +      level3_cache_assoc = handle_amd (_SC_LEVEL3_CACHE_ASSOC);
> > +      level3_cache_linesize = handle_amd (_SC_LEVEL3_CACHE_LINESIZE);
> > +
> > +      /* Get maximum extended function. */
> > +      __cpuid (0x80000000, max_cpuid_ex, ebx, ecx, edx);
> > +
> > +      if (shared <= 0)
> > +     /* No shared L3 cache.  All we have is the L2 cache.  */
> > +     shared = core;
> > +      else
> > +     {
> > +       /* Figure out the number of logical threads that share L3.  */
> > +       if (max_cpuid_ex >= 0x80000008)
> > +         {
> > +           /* Get width of APIC ID.  */
> > +           __cpuid (0x80000008, max_cpuid_ex, ebx, ecx, edx);
> > +           threads = 1 << ((ecx >> 12) & 0x0f);
> > +         }
> > +
> > +       if (threads == 0 || cpu_features->basic.family >= 0x17)
> > +         {
> > +           /* If APIC ID width is not available, use logical
> > +              processor count.  */
> > +           __cpuid (0x00000001, max_cpuid_ex, ebx, ecx, edx);
> > +
> > +           if ((edx & (1 << 28)) != 0)
> > +             threads = (ebx >> 16) & 0xff;
> > +         }
> > +
> > +       /* Cap usage of highest cache level to the number of
> > +          supported threads.  */
> > +       if (threads > 0)
> > +         shared /= threads;
> > +
> > +       /* Get shared cache per ccx for Zen architectures.  */
> > +       if (cpu_features->basic.family >= 0x17)
> > +         {
> > +           unsigned int eax;
> > +
> > +           /* Get number of threads share the L3 cache in CCX.  */
> > +           __cpuid_count (0x8000001D, 0x3, eax, ebx, ecx, edx);
> > +
> > +           unsigned int threads_per_ccx = ((eax >> 14) & 0xfff) + 1;
> > +           shared *= threads_per_ccx;
> > +         }
> > +       else
> > +         {
> > +           /* Account for exclusive L2 and L3 caches.  */
> > +           shared += core;
> > +            }
> > +     }
> > +    }
> > +
> > +  cpu_features->level1_icache_size = level1_icache_size;
> > +  cpu_features->level1_dcache_size = level1_dcache_size;
> > +  cpu_features->level1_dcache_assoc = level1_dcache_assoc;
> > +  cpu_features->level1_dcache_linesize = level1_dcache_linesize;
> > +  cpu_features->level2_cache_size = level2_cache_size;
> > +  cpu_features->level2_cache_assoc = level2_cache_assoc;
> > +  cpu_features->level2_cache_linesize = level2_cache_linesize;
> > +  cpu_features->level3_cache_size = level3_cache_size;
> > +  cpu_features->level3_cache_assoc = level3_cache_assoc;
> > +  cpu_features->level3_cache_linesize = level3_cache_linesize;
> > +  cpu_features->level4_cache_size = level4_cache_size;
>
> Ok, so you are expanding the definitions by family.
>
> > +
> > +  /* The default setting for the non_temporal threshold is 3/4 of one
> > +     thread's share of the chip's cache. For most Intel and AMD processors
> > +     with an initial release date between 2017 and 2020, a thread's typical
> > +     share of the cache is from 500 KBytes to 2 MBytes. Using the 3/4
> > +     threshold leaves 125 KBytes to 500 KBytes of the thread's data
> > +     in cache after a maximum temporal copy, which will maintain
> > +     in cache a reasonable portion of the thread's stack and other
> > +     active data. If the threshold is set higher than one thread's
> > +     share of the cache, it has a substantial risk of negatively
> > +     impacting the performance of other threads running on the chip. */
> > +  unsigned long int non_temporal_threshold = shared * 3 / 4;
> > +
> > +#if HAVE_TUNABLES
> > +  /* NB: The REP MOVSB threshold must be greater than VEC_SIZE * 8.  */
> > +  unsigned int minimum_rep_movsb_threshold;
> > +#endif
> > +  /* NB: The default REP MOVSB threshold is 2048 * (VEC_SIZE / 16).  */
> > +  unsigned int rep_movsb_threshold;
> > +  if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> > +      && !CPU_FEATURE_PREFERRED_P (cpu_features, Prefer_No_AVX512))
> > +    {
> > +      rep_movsb_threshold = 2048 * (64 / 16);
> > +#if HAVE_TUNABLES
> > +      minimum_rep_movsb_threshold = 64 * 8;
> > +#endif
> > +    }
> > +  else if (CPU_FEATURE_PREFERRED_P (cpu_features,
> > +                                 AVX_Fast_Unaligned_Load))
> > +    {
> > +      rep_movsb_threshold = 2048 * (32 / 16);
> > +#if HAVE_TUNABLES
> > +      minimum_rep_movsb_threshold = 32 * 8;
> > +#endif
> > +    }
> > +  else
> > +    {
> > +      rep_movsb_threshold = 2048 * (16 / 16);
> > +#if HAVE_TUNABLES
> > +      minimum_rep_movsb_threshold = 16 * 8;
> > +#endif
> > +    }
> > +
> > +  /* The default threshold to use Enhanced REP STOSB.  */
> > +  unsigned long int rep_stosb_threshold = 2048;
> > +
>
> Ok.
>
> > +#if HAVE_TUNABLES
> > +  long int tunable_size;
> > +
> > +  tunable_size = TUNABLE_GET (x86_data_cache_size, long int, NULL);
> > +  /* NB: Ignore the default value 0.  */
> > +  if (tunable_size)
>
> No implicit checks, same as the others below.

Fixed.

> > +    data = tunable_size;
> > +
> > +  tunable_size = TUNABLE_GET (x86_shared_cache_size, long int, NULL);
> > +  /* NB: Ignore the default value 0.  */
> > +  if (tunable_size)

Fixed.

> > +    shared = tunable_size;
> > +
> > +  tunable_size = TUNABLE_GET (x86_non_temporal_threshold, long int, NULL);
> > +  /* NB: Ignore the default value 0.  */
> > +  if (tunable_size)

Fixed.

> > +    non_temporal_threshold = tunable_size;
> > +
> > +  tunable_size = TUNABLE_GET (x86_rep_movsb_threshold, long int, NULL);
> > +  if (tunable_size > minimum_rep_movsb_threshold)
> > +    rep_movsb_threshold = tunable_size;
> > +
> > +  /* NB: The default value of the x86_rep_stosb_threshold tunable is the
> > +     same as the default value of __x86_rep_stosb_threshold and the
> > +     minimum value is fixed.  */
> > +  rep_stosb_threshold = TUNABLE_GET (x86_rep_stosb_threshold,
> > +                                  long int, NULL);
> > +
> > +  TUNABLE_SET_WITH_BOUNDS (x86_data_cache_size, long int, data,
> > +                        0, (long int) -1);
> > +  TUNABLE_SET_WITH_BOUNDS (x86_shared_cache_size, long int, shared,
> > +                        0, (long int) -1);
> > +  TUNABLE_SET_WITH_BOUNDS (x86_non_temporal_threshold, long int,
> > +                        non_temporal_threshold, 0, (long int) -1);
> > +  TUNABLE_SET_WITH_BOUNDS (x86_rep_movsb_threshold, long int,
> > +                        rep_movsb_threshold,
> > +                        minimum_rep_movsb_threshold, (long int) -1);
> > +  TUNABLE_SET_WITH_BOUNDS (x86_rep_stosb_threshold, long int,
> > +                        rep_stosb_threshold, 1, (long int) -1);
> > +#endif
>
> Ok.  Are the bounds ok for the architecture?

The bounds are OK since they are derived from CPUID.

> > +
> > +  cpu_features->data_cache_size = data;
> > +  cpu_features->shared_cache_size = shared;
> > +  cpu_features->non_temporal_threshold = non_temporal_threshold;
> > +  cpu_features->rep_movsb_threshold = rep_movsb_threshold;
> > +  cpu_features->rep_stosb_threshold = rep_stosb_threshold;
> > +}
>
> Ok.
>
> > diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
> > index f62be0b9b3..3f3bd93320 100644
> > --- a/sysdeps/x86/include/cpu-features.h
> > +++ b/sysdeps/x86/include/cpu-features.h
> > @@ -153,6 +153,28 @@ struct cpu_features
> >    unsigned long int rep_movsb_threshold;
> >    /* Threshold to use "rep stosb".  */
> >    unsigned long int rep_stosb_threshold;
> > +  /* _SC_LEVEL1_ICACHE_SIZE.  */
> > +  unsigned long int level1_icache_size;
> > +  /* _SC_LEVEL1_DCACHE_SIZE.  */
> > +  unsigned long int level1_dcache_size;
> > +  /* _SC_LEVEL1_DCACHE_ASSOC.  */
> > +  unsigned long int level1_dcache_assoc;
> > +  /* _SC_LEVEL1_DCACHE_LINESIZE.  */
> > +  unsigned long int level1_dcache_linesize;
> > +  /* _SC_LEVEL2_CACHE_ASSOC.  */
> > +  unsigned long int level2_cache_size;
> > +  /* _SC_LEVEL2_DCACHE_ASSOC.  */
> > +  unsigned long int level2_cache_assoc;
> > +  /* _SC_LEVEL2_CACHE_LINESIZE.  */
> > +  unsigned long int level2_cache_linesize;
> > +  /* /_SC_LEVEL3_CACHE_SIZE.  */
> > +  unsigned long int level3_cache_size;
> > +  /* _SC_LEVEL3_CACHE_ASSOC.  */
> > +  unsigned long int level3_cache_assoc;
> > +  /* _SC_LEVEL3_CACHE_LINESIZE.  */
> > +  unsigned long int level3_cache_linesize;
> > +  /* /_SC_LEVEL4_CACHE_SIZE.  */
> > +  unsigned long int level4_cache_size;
> >  };
> >
> >  # if defined (_LIBC) && !IS_IN (nonlib)
> >
>
> Ok.

Here is the updated patch I am checking in.

Thanks.
diff mbox series

Patch

From ebef59ae6f104fd0c8b832a7f56136d39fb4e9e3 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 18 Sep 2020 07:55:14 -0700
Subject: [PATCH] x86: Move x86 processor cache info to cpu_features

1. Move x86 processor cache info to _dl_x86_cpu_features in ld.so.
2. Update tunable bounds with TUNABLE_SET_WITH_BOUNDS.
3. Move x86 cache info initialization to dl-cacheinfo.h and initialize
x86 cache info in init_cpu_features ().
4. Put x86 cache info for libc in cacheinfo.h, which is included in
libc-start.c in libc.a and is included in cacheinfo.c in libc.so.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
---
 sysdeps/x86/cacheinfo.c            |  46 ++-
 sysdeps/x86/cacheinfo.h            | 400 ++-----------------------
 sysdeps/x86/cpu-features.c         |  35 +--
 sysdeps/x86/dl-cacheinfo.h         | 460 +++++++++++++++++++++++++++++
 sysdeps/x86/include/cpu-features.h |  22 ++
 5 files changed, 551 insertions(+), 412 deletions(-)

diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
index ed4e1a5b58..350cba5fda 100644
--- a/sysdeps/x86/cacheinfo.c
+++ b/sysdeps/x86/cacheinfo.c
@@ -18,11 +18,8 @@ 
 
 #if IS_IN (libc)
 
-#include <assert.h>
 #include <unistd.h>
-#include <cpuid.h>
 #include <ldsodefs.h>
-#include <dl-cacheinfo.h>
 
 /* Get the value of the system variable NAME.  */
 long int
@@ -30,20 +27,45 @@  attribute_hidden
 __cache_sysconf (int name)
 {
   const struct cpu_features *cpu_features = __get_cpu_features ();
+  switch (name)
+    {
+    case _SC_LEVEL1_ICACHE_SIZE:
+      return cpu_features->level1_icache_size;
 
-  if (cpu_features->basic.kind == arch_kind_intel)
-    return handle_intel (name, cpu_features);
+    case _SC_LEVEL1_DCACHE_SIZE:
+      return cpu_features->level1_dcache_size;
 
-  if (cpu_features->basic.kind == arch_kind_amd)
-    return handle_amd (name);
+    case _SC_LEVEL1_DCACHE_ASSOC:
+      return cpu_features->level1_dcache_assoc;
 
-  if (cpu_features->basic.kind == arch_kind_zhaoxin)
-    return handle_zhaoxin (name);
+    case _SC_LEVEL1_DCACHE_LINESIZE:
+      return cpu_features->level1_dcache_linesize;
 
-  // XXX Fill in more vendors.
+    case _SC_LEVEL2_CACHE_SIZE:
+      return cpu_features->level2_cache_size;
 
-  /* CPU not known, we have no information.  */
-  return 0;
+    case _SC_LEVEL2_CACHE_ASSOC:
+      return cpu_features->level2_cache_assoc;
+
+    case _SC_LEVEL2_CACHE_LINESIZE:
+      return cpu_features->level2_cache_linesize;
+
+    case _SC_LEVEL3_CACHE_SIZE:
+      return cpu_features->level3_cache_size;
+
+    case _SC_LEVEL3_CACHE_ASSOC:
+      return cpu_features->level3_cache_assoc;
+
+    case _SC_LEVEL3_CACHE_LINESIZE:
+      return cpu_features->level3_cache_linesize;
+
+    case _SC_LEVEL4_CACHE_SIZE:
+      return cpu_features->level4_cache_size;
+
+    default:
+      break;
+    }
+  return -1;
 }
 
 # ifdef SHARED
diff --git a/sysdeps/x86/cacheinfo.h b/sysdeps/x86/cacheinfo.h
index 00d2d8a52a..68c253542f 100644
--- a/sysdeps/x86/cacheinfo.h
+++ b/sysdeps/x86/cacheinfo.h
@@ -18,7 +18,16 @@ 
 
 #include <assert.h>
 #include <unistd.h>
+#include <cpuid.h>
+#include <cpu-features.h>
 
+#if HAVE_TUNABLES
+# define TUNABLE_NAMESPACE cpu
+# include <unistd.h>		/* Get STDOUT_FILENO for _dl_printf.  */
+# include <elf/dl-tunables.h>
+#endif
+
+#if IS_IN (libc)
 /* Data cache size for use in memory and string routines, typically
    L1 size, rounded to multiple of 256 bytes.  */
 long int __x86_data_cache_size_half attribute_hidden = 32 * 1024 / 2;
@@ -45,385 +54,30 @@  long int __x86_rep_movsb_threshold attribute_hidden = 2048;
 /* Threshold to use Enhanced REP STOSB.  */
 long int __x86_rep_stosb_threshold attribute_hidden = 2048;
 
-static void
-get_common_cache_info (long int *shared_ptr, unsigned int *threads_ptr,
-		       long int core)
-{
-  unsigned int eax;
-  unsigned int ebx;
-  unsigned int ecx;
-  unsigned int edx;
-
-  /* Number of logical processors sharing L2 cache.  */
-  int threads_l2;
-
-  /* Number of logical processors sharing L3 cache.  */
-  int threads_l3;
-
-  const struct cpu_features *cpu_features = __get_cpu_features ();
-  int max_cpuid = cpu_features->basic.max_cpuid;
-  unsigned int family = cpu_features->basic.family;
-  unsigned int model = cpu_features->basic.model;
-  long int shared = *shared_ptr;
-  unsigned int threads = *threads_ptr;
-  bool inclusive_cache = true;
-  bool support_count_mask = true;
-
-  /* Try L3 first.  */
-  unsigned int level = 3;
-
-  if (cpu_features->basic.kind == arch_kind_zhaoxin && family == 6)
-    support_count_mask = false;
-
-  if (shared <= 0)
-    {
-      /* Try L2 otherwise.  */
-      level  = 2;
-      shared = core;
-      threads_l2 = 0;
-      threads_l3 = -1;
-    }
-  else
-    {
-      threads_l2 = 0;
-      threads_l3 = 0;
-    }
-
-  /* A value of 0 for the HTT bit indicates there is only a single
-     logical processor.  */
-  if (HAS_CPU_FEATURE (HTT))
-    {
-      /* Figure out the number of logical threads that share the
-         highest cache level.  */
-      if (max_cpuid >= 4)
-        {
-          int i = 0;
-
-          /* Query until cache level 2 and 3 are enumerated.  */
-          int check = 0x1 | (threads_l3 == 0) << 1;
-          do
-            {
-              __cpuid_count (4, i++, eax, ebx, ecx, edx);
-
-              /* There seems to be a bug in at least some Pentium Ds
-                 which sometimes fail to iterate all cache parameters.
-                 Do not loop indefinitely here, stop in this case and
-                 assume there is no such information.  */
-              if (cpu_features->basic.kind == arch_kind_intel
-                  && (eax & 0x1f) == 0 )
-                goto intel_bug_no_cache_info;
-
-              switch ((eax >> 5) & 0x7)
-                {
-                  default:
-                    break;
-                  case 2:
-                    if ((check & 0x1))
-                      {
-                        /* Get maximum number of logical processors
-                           sharing L2 cache.  */
-                        threads_l2 = (eax >> 14) & 0x3ff;
-                        check &= ~0x1;
-                      }
-                    break;
-                  case 3:
-                    if ((check & (0x1 << 1)))
-                      {
-                        /* Get maximum number of logical processors
-                           sharing L3 cache.  */
-                        threads_l3 = (eax >> 14) & 0x3ff;
-
-                        /* Check if L2 and L3 caches are inclusive.  */
-                        inclusive_cache = (edx & 0x2) != 0;
-                        check &= ~(0x1 << 1);
-                      }
-                    break;
-                }
-            }
-          while (check);
-
-          /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
-             numbers of addressable IDs for logical processors sharing
-             the cache, instead of the maximum number of threads
-             sharing the cache.  */
-          if (max_cpuid >= 11 && support_count_mask)
-            {
-              /* Find the number of logical processors shipped in
-                 one core and apply count mask.  */
-              i = 0;
-
-              /* Count SMT only if there is L3 cache.  Always count
-                 core if there is no L3 cache.  */
-              int count = ((threads_l2 > 0 && level == 3)
-                           | ((threads_l3 > 0
-                               || (threads_l2 > 0 && level == 2)) << 1));
-
-              while (count)
-                {
-                  __cpuid_count (11, i++, eax, ebx, ecx, edx);
-
-                  int shipped = ebx & 0xff;
-                  int type = ecx & 0xff00;
-                  if (shipped == 0 || type == 0)
-                    break;
-                  else if (type == 0x100)
-                    {
-                      /* Count SMT.  */
-                      if ((count & 0x1))
-                        {
-                          int count_mask;
-
-                          /* Compute count mask.  */
-                          asm ("bsr %1, %0"
-                               : "=r" (count_mask) : "g" (threads_l2));
-                          count_mask = ~(-1 << (count_mask + 1));
-                          threads_l2 = (shipped - 1) & count_mask;
-                          count &= ~0x1;
-                        }
-                    }
-                  else if (type == 0x200)
-                    {
-                      /* Count core.  */
-                      if ((count & (0x1 << 1)))
-                        {
-                          int count_mask;
-                          int threads_core
-                            = (level == 2 ? threads_l2 : threads_l3);
-
-                          /* Compute count mask.  */
-                          asm ("bsr %1, %0"
-                               : "=r" (count_mask) : "g" (threads_core));
-                          count_mask = ~(-1 << (count_mask + 1));
-                          threads_core = (shipped - 1) & count_mask;
-                          if (level == 2)
-                            threads_l2 = threads_core;
-                          else
-                            threads_l3 = threads_core;
-                          count &= ~(0x1 << 1);
-                        }
-                    }
-                }
-            }
-          if (threads_l2 > 0)
-            threads_l2 += 1;
-          if (threads_l3 > 0)
-            threads_l3 += 1;
-          if (level == 2)
-            {
-              if (threads_l2)
-                {
-                  threads = threads_l2;
-                  if (cpu_features->basic.kind == arch_kind_intel
-                      && threads > 2
-                      && family == 6)
-                    switch (model)
-                      {
-                        case 0x37:
-                        case 0x4a:
-                        case 0x4d:
-                        case 0x5a:
-                        case 0x5d:
-                          /* Silvermont has L2 cache shared by 2 cores.  */
-                          threads = 2;
-                          break;
-                        default:
-                          break;
-                      }
-                }
-            }
-          else if (threads_l3)
-            threads = threads_l3;
-        }
-      else
-        {
-intel_bug_no_cache_info:
-          /* Assume that all logical threads share the highest cache
-             level.  */
-          threads
-            = ((cpu_features->features[COMMON_CPUID_INDEX_1].cpuid.ebx
-                >> 16) & 0xff);
-        }
-
-        /* Cap usage of highest cache level to the number of supported
-           threads.  */
-        if (shared > 0 && threads > 0)
-          shared /= threads;
-    }
-
-  /* Account for non-inclusive L2 and L3 caches.  */
-  if (!inclusive_cache)
-    {
-      if (threads_l2 > 0)
-        core /= threads_l2;
-      shared += core;
-    }
-
-  *shared_ptr = shared;
-  *threads_ptr = threads;
-}
-
 static void
 init_cacheinfo (void)
 {
-  /* Find out what brand of processor.  */
-  unsigned int ebx;
-  unsigned int ecx;
-  unsigned int edx;
-  int max_cpuid_ex;
-  long int data = -1;
-  long int shared = -1;
-  long int core;
-  unsigned int threads = 0;
   const struct cpu_features *cpu_features = __get_cpu_features ();
+  long int data = cpu_features->data_cache_size;
+  __x86_raw_data_cache_size_half = data / 2;
+  __x86_raw_data_cache_size = data;
+  /* Round data cache size to multiple of 256 bytes.  */
+  data = data & ~255L;
+  __x86_data_cache_size_half = data / 2;
+  __x86_data_cache_size = data;
+
+  long int shared = cpu_features->shared_cache_size;
+  __x86_raw_shared_cache_size_half = shared / 2;
+  __x86_raw_shared_cache_size = shared;
+  /* Round shared cache size to multiple of 256 bytes.  */
+  shared = shared & ~255L;
+  __x86_shared_cache_size_half = shared / 2;
+  __x86_shared_cache_size = shared;
 
-  /* NB: In libc.so, cpu_features is defined in ld.so and is initialized
-     by DL_PLATFORM_INIT or IFUNC relocation before init_cacheinfo is
-     called by IFUNC relocation.  In libc.a, init_cacheinfo is called
-     from init_cpu_features by ARCH_INIT_CPU_FEATURES.  */
-  assert (cpu_features->basic.kind != arch_kind_unknown);
-
-  if (cpu_features->basic.kind == arch_kind_intel)
-    {
-      data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, cpu_features);
-      core = handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
-      shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, cpu_features);
-
-      get_common_cache_info (&shared, &threads, core);
-    }
-  else if (cpu_features->basic.kind == arch_kind_zhaoxin)
-    {
-      data = handle_zhaoxin (_SC_LEVEL1_DCACHE_SIZE);
-      core = handle_zhaoxin (_SC_LEVEL2_CACHE_SIZE);
-      shared = handle_zhaoxin (_SC_LEVEL3_CACHE_SIZE);
-
-      get_common_cache_info (&shared, &threads, core);
-    }
-  else if (cpu_features->basic.kind == arch_kind_amd)
-    {
-      data   = handle_amd (_SC_LEVEL1_DCACHE_SIZE);
-      long int core = handle_amd (_SC_LEVEL2_CACHE_SIZE);
-      shared = handle_amd (_SC_LEVEL3_CACHE_SIZE);
-
-      /* Get maximum extended function. */
-      __cpuid (0x80000000, max_cpuid_ex, ebx, ecx, edx);
-
-      if (shared <= 0)
-	/* No shared L3 cache.  All we have is the L2 cache.  */
-	shared = core;
-      else
-	{
-	  /* Figure out the number of logical threads that share L3.  */
-	  if (max_cpuid_ex >= 0x80000008)
-	    {
-	      /* Get width of APIC ID.  */
-	      __cpuid (0x80000008, max_cpuid_ex, ebx, ecx, edx);
-	      threads = 1 << ((ecx >> 12) & 0x0f);
-	    }
-
-	  if (threads == 0 || cpu_features->basic.family >= 0x17)
-	    {
-	      /* If APIC ID width is not available, use logical
-		 processor count.  */
-	      __cpuid (0x00000001, max_cpuid_ex, ebx, ecx, edx);
-
-	      if ((edx & (1 << 28)) != 0)
-		threads = (ebx >> 16) & 0xff;
-	    }
-
-	  /* Cap usage of highest cache level to the number of
-	     supported threads.  */
-	  if (threads > 0)
-	    shared /= threads;
-
-	  /* Get shared cache per ccx for Zen architectures.  */
-	  if (cpu_features->basic.family >= 0x17)
-	    {
-	      unsigned int eax;
-
-	      /* Get number of threads share the L3 cache in CCX.  */
-	      __cpuid_count (0x8000001D, 0x3, eax, ebx, ecx, edx);
-
-	      unsigned int threads_per_ccx = ((eax >> 14) & 0xfff) + 1;
-	      shared *= threads_per_ccx;
-	    }
-	  else
-	    {
-	      /* Account for exclusive L2 and L3 caches.  */
-	      shared += core;
-            }
-      }
-    }
-
-  /* Prefer cache size configure via tuning.  */
-  if (cpu_features->data_cache_size != 0)
-    data = cpu_features->data_cache_size;
-
-  if (data > 0)
-    {
-      __x86_raw_data_cache_size_half = data / 2;
-      __x86_raw_data_cache_size = data;
-      /* Round data cache size to multiple of 256 bytes.  */
-      data = data & ~255L;
-      __x86_data_cache_size_half = data / 2;
-      __x86_data_cache_size = data;
-    }
-
-  /* Prefer cache size configure via tuning.  */
-  if (cpu_features->shared_cache_size != 0)
-    shared = cpu_features->shared_cache_size;
-
-  if (shared > 0)
-    {
-      __x86_raw_shared_cache_size_half = shared / 2;
-      __x86_raw_shared_cache_size = shared;
-      /* Round shared cache size to multiple of 256 bytes.  */
-      shared = shared & ~255L;
-      __x86_shared_cache_size_half = shared / 2;
-      __x86_shared_cache_size = shared;
-    }
-
-  /* The default setting for the non_temporal threshold is 3/4 of one
-     thread's share of the chip's cache. For most Intel and AMD processors
-     with an initial release date between 2017 and 2020, a thread's typical
-     share of the cache is from 500 KBytes to 2 MBytes. Using the 3/4
-     threshold leaves 125 KBytes to 500 KBytes of the thread's data
-     in cache after a maximum temporal copy, which will maintain
-     in cache a reasonable portion of the thread's stack and other
-     active data. If the threshold is set higher than one thread's
-     share of the cache, it has a substantial risk of negatively
-     impacting the performance of other threads running on the chip. */
   __x86_shared_non_temporal_threshold
-    = (cpu_features->non_temporal_threshold != 0
-       ? cpu_features->non_temporal_threshold
-       : __x86_shared_cache_size * 3 / 4);
-
-  /* NB: The REP MOVSB threshold must be greater than VEC_SIZE * 8.  */
-  unsigned int minimum_rep_movsb_threshold;
-  /* NB: The default REP MOVSB threshold is 2048 * (VEC_SIZE / 16).  */
-  unsigned int rep_movsb_threshold;
-  if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
-      && !CPU_FEATURE_PREFERRED_P (cpu_features, Prefer_No_AVX512))
-    {
-      rep_movsb_threshold = 2048 * (64 / 16);
-      minimum_rep_movsb_threshold = 64 * 8;
-    }
-  else if (CPU_FEATURE_PREFERRED_P (cpu_features,
-				    AVX_Fast_Unaligned_Load))
-    {
-      rep_movsb_threshold = 2048 * (32 / 16);
-      minimum_rep_movsb_threshold = 32 * 8;
-    }
-  else
-    {
-      rep_movsb_threshold = 2048 * (16 / 16);
-      minimum_rep_movsb_threshold = 16 * 8;
-    }
-  if (cpu_features->rep_movsb_threshold > minimum_rep_movsb_threshold)
-    __x86_rep_movsb_threshold = cpu_features->rep_movsb_threshold;
-  else
-    __x86_rep_movsb_threshold = rep_movsb_threshold;
+    = cpu_features->non_temporal_threshold;
 
-# if HAVE_TUNABLES
+  __x86_rep_movsb_threshold = cpu_features->rep_movsb_threshold;
   __x86_rep_stosb_threshold = cpu_features->rep_stosb_threshold;
-# endif
 }
+#endif
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index e7da682a2e..06e4307b71 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -16,22 +16,13 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <cpuid.h>
 #include <dl-hwcap.h>
 #include <libc-pointer-arith.h>
 #include <get-isa-level.h>
-#if IS_IN (libc) && !defined SHARED
-# include <assert.h>
-# include <unistd.h>
-# include <dl-cacheinfo.h>
-# include <cacheinfo.h>
-#endif
+#include <cacheinfo.h>
+#include <dl-cacheinfo.h>
 
 #if HAVE_TUNABLES
-# define TUNABLE_NAMESPACE cpu
-# include <unistd.h>		/* Get STDOUT_FILENO for _dl_printf.  */
-# include <elf/dl-tunables.h>
-
 extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *)
   attribute_hidden;
 
@@ -646,24 +637,14 @@  no_cpuid:
   cpu_features->basic.model = model;
   cpu_features->basic.stepping = stepping;
 
+  dl_init_cacheinfo (cpu_features);
+
 #if HAVE_TUNABLES
   TUNABLE_GET (hwcaps, tunable_val_t *, TUNABLE_CALLBACK (set_hwcaps));
-  cpu_features->non_temporal_threshold
-    = TUNABLE_GET (x86_non_temporal_threshold, long int, NULL);
-  cpu_features->rep_movsb_threshold
-    = TUNABLE_GET (x86_rep_movsb_threshold, long int, NULL);
-  cpu_features->rep_stosb_threshold
-    = TUNABLE_GET (x86_rep_stosb_threshold, long int, NULL);
-  cpu_features->data_cache_size
-    = TUNABLE_GET (x86_data_cache_size, long int, NULL);
-  cpu_features->shared_cache_size
-    = TUNABLE_GET (x86_shared_cache_size, long int, NULL);
-#endif
-
-  /* Reuse dl_platform, dl_hwcap and dl_hwcap_mask for x86.  */
-#if !HAVE_TUNABLES && defined SHARED
-  /* The glibc.cpu.hwcap_mask tunable is initialized already, so no need to do
-     this.  */
+#elif defined SHARED
+  /* Reuse dl_platform, dl_hwcap and dl_hwcap_mask for x86.  The
+     glibc.cpu.hwcap_mask tunable is initialized already, so no
+     need to do this.  */
   GLRO(dl_hwcap_mask) = HWCAP_IMPORTANT;
 #endif
 
diff --git a/sysdeps/x86/dl-cacheinfo.h b/sysdeps/x86/dl-cacheinfo.h
index 6adce4147c..96c49f2411 100644
--- a/sysdeps/x86/dl-cacheinfo.h
+++ b/sysdeps/x86/dl-cacheinfo.h
@@ -476,3 +476,463 @@  handle_zhaoxin (int name)
   /* Nothing found.  */
   return 0;
 }
+
+static void
+get_common_cache_info (long int *shared_ptr, unsigned int *threads_ptr,
+                long int core)
+{
+  unsigned int eax;
+  unsigned int ebx;
+  unsigned int ecx;
+  unsigned int edx;
+
+  /* Number of logical processors sharing L2 cache.  */
+  int threads_l2;
+
+  /* Number of logical processors sharing L3 cache.  */
+  int threads_l3;
+
+  const struct cpu_features *cpu_features = __get_cpu_features ();
+  int max_cpuid = cpu_features->basic.max_cpuid;
+  unsigned int family = cpu_features->basic.family;
+  unsigned int model = cpu_features->basic.model;
+  long int shared = *shared_ptr;
+  unsigned int threads = *threads_ptr;
+  bool inclusive_cache = true;
+  bool support_count_mask = true;
+
+  /* Try L3 first.  */
+  unsigned int level = 3;
+
+  if (cpu_features->basic.kind == arch_kind_zhaoxin && family == 6)
+    support_count_mask = false;
+
+  if (shared <= 0)
+    {
+      /* Try L2 otherwise.  */
+      level  = 2;
+      shared = core;
+      threads_l2 = 0;
+      threads_l3 = -1;
+    }
+  else
+    {
+      threads_l2 = 0;
+      threads_l3 = 0;
+    }
+
+  /* A value of 0 for the HTT bit indicates there is only a single
+     logical processor.  */
+  if (HAS_CPU_FEATURE (HTT))
+    {
+      /* Figure out the number of logical threads that share the
+         highest cache level.  */
+      if (max_cpuid >= 4)
+        {
+          int i = 0;
+
+          /* Query until cache level 2 and 3 are enumerated.  */
+          int check = 0x1 | (threads_l3 == 0) << 1;
+          do
+            {
+              __cpuid_count (4, i++, eax, ebx, ecx, edx);
+
+              /* There seems to be a bug in at least some Pentium Ds
+                 which sometimes fail to iterate all cache parameters.
+                 Do not loop indefinitely here, stop in this case and
+                 assume there is no such information.  */
+              if (cpu_features->basic.kind == arch_kind_intel
+                  && (eax & 0x1f) == 0 )
+                goto intel_bug_no_cache_info;
+
+              switch ((eax >> 5) & 0x7)
+                {
+                  default:
+                    break;
+                  case 2:
+                    if ((check & 0x1))
+                      {
+                        /* Get maximum number of logical processors
+                           sharing L2 cache.  */
+                        threads_l2 = (eax >> 14) & 0x3ff;
+                        check &= ~0x1;
+                      }
+                    break;
+                  case 3:
+                    if ((check & (0x1 << 1)))
+                      {
+                        /* Get maximum number of logical processors
+                           sharing L3 cache.  */
+                        threads_l3 = (eax >> 14) & 0x3ff;
+
+                        /* Check if L2 and L3 caches are inclusive.  */
+                        inclusive_cache = (edx & 0x2) != 0;
+                        check &= ~(0x1 << 1);
+                      }
+                    break;
+                }
+            }
+          while (check);
+
+          /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
+             numbers of addressable IDs for logical processors sharing
+             the cache, instead of the maximum number of threads
+             sharing the cache.  */
+          if (max_cpuid >= 11 && support_count_mask)
+            {
+              /* Find the number of logical processors shipped in
+                 one core and apply count mask.  */
+              i = 0;
+
+              /* Count SMT only if there is L3 cache.  Always count
+                 core if there is no L3 cache.  */
+              int count = ((threads_l2 > 0 && level == 3)
+                           | ((threads_l3 > 0
+                               || (threads_l2 > 0 && level == 2)) << 1));
+
+              while (count)
+                {
+                  __cpuid_count (11, i++, eax, ebx, ecx, edx);
+
+                  int shipped = ebx & 0xff;
+                  int type = ecx & 0xff00;
+                  if (shipped == 0 || type == 0)
+                    break;
+                  else if (type == 0x100)
+                    {
+                      /* Count SMT.  */
+                      if ((count & 0x1))
+                        {
+                          int count_mask;
+
+                          /* Compute count mask.  */
+                          asm ("bsr %1, %0"
+                               : "=r" (count_mask) : "g" (threads_l2));
+                          count_mask = ~(-1 << (count_mask + 1));
+                          threads_l2 = (shipped - 1) & count_mask;
+                          count &= ~0x1;
+                        }
+                    }
+                  else if (type == 0x200)
+                    {
+                      /* Count core.  */
+                      if ((count & (0x1 << 1)))
+                        {
+                          int count_mask;
+                          int threads_core
+                            = (level == 2 ? threads_l2 : threads_l3);
+
+                          /* Compute count mask.  */
+                          asm ("bsr %1, %0"
+                               : "=r" (count_mask) : "g" (threads_core));
+                          count_mask = ~(-1 << (count_mask + 1));
+                          threads_core = (shipped - 1) & count_mask;
+                          if (level == 2)
+                            threads_l2 = threads_core;
+                          else
+                            threads_l3 = threads_core;
+                          count &= ~(0x1 << 1);
+                        }
+                    }
+                }
+            }
+          if (threads_l2 > 0)
+            threads_l2 += 1;
+          if (threads_l3 > 0)
+            threads_l3 += 1;
+          if (level == 2)
+            {
+              if (threads_l2)
+                {
+                  threads = threads_l2;
+                  if (cpu_features->basic.kind == arch_kind_intel
+                      && threads > 2
+                      && family == 6)
+                    switch (model)
+                      {
+                        case 0x37:
+                        case 0x4a:
+                        case 0x4d:
+                        case 0x5a:
+                        case 0x5d:
+                          /* Silvermont has L2 cache shared by 2 cores.  */
+                          threads = 2;
+                          break;
+                        default:
+                          break;
+                      }
+                }
+            }
+          else if (threads_l3)
+            threads = threads_l3;
+        }
+      else
+        {
+intel_bug_no_cache_info:
+          /* Assume that all logical threads share the highest cache
+             level.  */
+          threads
+            = ((cpu_features->features[COMMON_CPUID_INDEX_1].cpuid.ebx
+                >> 16) & 0xff);
+        }
+
+        /* Cap usage of highest cache level to the number of supported
+           threads.  */
+        if (shared > 0 && threads > 0)
+          shared /= threads;
+    }
+
+  /* Account for non-inclusive L2 and L3 caches.  */
+  if (!inclusive_cache)
+    {
+      if (threads_l2 > 0)
+        core /= threads_l2;
+      shared += core;
+    }
+
+  *shared_ptr = shared;
+  *threads_ptr = threads;
+}
+
+static void
+dl_init_cacheinfo (struct cpu_features *cpu_features)
+{
+  /* Find out what brand of processor.  */
+  unsigned int ebx;
+  unsigned int ecx;
+  unsigned int edx;
+  int max_cpuid_ex;
+  long int data = -1;
+  long int shared = -1;
+  long int core;
+  unsigned int threads = 0;
+  unsigned long int level1_icache_size = -1;
+  unsigned long int level1_dcache_size = -1;
+  unsigned long int level1_dcache_assoc = -1;
+  unsigned long int level1_dcache_linesize = -1;
+  unsigned long int level2_cache_size = -1;
+  unsigned long int level2_cache_assoc = -1;
+  unsigned long int level2_cache_linesize = -1;
+  unsigned long int level3_cache_size = -1;
+  unsigned long int level3_cache_assoc = -1;
+  unsigned long int level3_cache_linesize = -1;
+  unsigned long int level4_cache_size = -1;
+
+  if (cpu_features->basic.kind == arch_kind_intel)
+    {
+      data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, cpu_features);
+      core = handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
+      shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, cpu_features);
+
+      level1_icache_size
+	= handle_intel (_SC_LEVEL1_ICACHE_SIZE, cpu_features);
+      level1_dcache_size = data;
+      level1_dcache_assoc
+	= handle_intel (_SC_LEVEL1_DCACHE_ASSOC, cpu_features);
+      level1_dcache_linesize
+	= handle_intel (_SC_LEVEL1_DCACHE_LINESIZE, cpu_features);
+      level2_cache_size = core;
+      level2_cache_assoc
+	= handle_intel (_SC_LEVEL2_CACHE_ASSOC, cpu_features);
+      level2_cache_linesize
+	= handle_intel (_SC_LEVEL2_CACHE_LINESIZE, cpu_features);
+      level3_cache_size = shared;
+      level3_cache_assoc
+	= handle_intel (_SC_LEVEL3_CACHE_ASSOC, cpu_features);
+      level3_cache_linesize
+	= handle_intel (_SC_LEVEL3_CACHE_LINESIZE, cpu_features);
+      level4_cache_size
+	= handle_intel (_SC_LEVEL4_CACHE_SIZE, cpu_features);
+
+      get_common_cache_info (&shared, &threads, core);
+    }
+  else if (cpu_features->basic.kind == arch_kind_zhaoxin)
+    {
+      data = handle_zhaoxin (_SC_LEVEL1_DCACHE_SIZE);
+      core = handle_zhaoxin (_SC_LEVEL2_CACHE_SIZE);
+      shared = handle_zhaoxin (_SC_LEVEL3_CACHE_SIZE);
+
+      level1_icache_size = handle_zhaoxin (_SC_LEVEL1_ICACHE_SIZE);
+      level1_dcache_size = data;
+      level1_dcache_assoc = handle_zhaoxin (_SC_LEVEL1_DCACHE_ASSOC);
+      level1_dcache_linesize = handle_zhaoxin (_SC_LEVEL1_DCACHE_LINESIZE);
+      level2_cache_size = core;
+      level2_cache_assoc = handle_zhaoxin (_SC_LEVEL2_CACHE_ASSOC);
+      level2_cache_linesize = handle_zhaoxin (_SC_LEVEL2_CACHE_LINESIZE);
+      level3_cache_size = shared;
+      level3_cache_assoc = handle_zhaoxin (_SC_LEVEL3_CACHE_ASSOC);
+      level3_cache_linesize = handle_zhaoxin (_SC_LEVEL3_CACHE_LINESIZE);
+
+      get_common_cache_info (&shared, &threads, core);
+    }
+  else if (cpu_features->basic.kind == arch_kind_amd)
+    {
+      data  = handle_amd (_SC_LEVEL1_DCACHE_SIZE);
+      core = handle_amd (_SC_LEVEL2_CACHE_SIZE);
+      shared = handle_amd (_SC_LEVEL3_CACHE_SIZE);
+
+      level1_icache_size = handle_amd (_SC_LEVEL1_ICACHE_SIZE);
+      level1_dcache_size = data;
+      level1_dcache_assoc = handle_amd (_SC_LEVEL1_DCACHE_ASSOC);
+      level1_dcache_linesize = handle_amd (_SC_LEVEL1_DCACHE_LINESIZE);
+      level2_cache_size = core;
+      level2_cache_assoc = handle_amd (_SC_LEVEL2_CACHE_ASSOC);
+      level2_cache_linesize = handle_amd (_SC_LEVEL2_CACHE_LINESIZE);
+      level3_cache_size = shared;
+      level3_cache_assoc = handle_amd (_SC_LEVEL3_CACHE_ASSOC);
+      level3_cache_linesize = handle_amd (_SC_LEVEL3_CACHE_LINESIZE);
+
+      /* Get maximum extended function. */
+      __cpuid (0x80000000, max_cpuid_ex, ebx, ecx, edx);
+
+      if (shared <= 0)
+	/* No shared L3 cache.  All we have is the L2 cache.  */
+	shared = core;
+      else
+	{
+	  /* Figure out the number of logical threads that share L3.  */
+	  if (max_cpuid_ex >= 0x80000008)
+	    {
+	      /* Get width of APIC ID.  */
+	      __cpuid (0x80000008, max_cpuid_ex, ebx, ecx, edx);
+	      threads = 1 << ((ecx >> 12) & 0x0f);
+	    }
+
+	  if (threads == 0 || cpu_features->basic.family >= 0x17)
+	    {
+	      /* If APIC ID width is not available, use logical
+		 processor count.  */
+	      __cpuid (0x00000001, max_cpuid_ex, ebx, ecx, edx);
+
+	      if ((edx & (1 << 28)) != 0)
+		threads = (ebx >> 16) & 0xff;
+	    }
+
+	  /* Cap usage of highest cache level to the number of
+	     supported threads.  */
+	  if (threads > 0)
+	    shared /= threads;
+
+	  /* Get shared cache per ccx for Zen architectures.  */
+	  if (cpu_features->basic.family >= 0x17)
+	    {
+	      unsigned int eax;
+
+	      /* Get number of threads share the L3 cache in CCX.  */
+	      __cpuid_count (0x8000001D, 0x3, eax, ebx, ecx, edx);
+
+	      unsigned int threads_per_ccx = ((eax >> 14) & 0xfff) + 1;
+	      shared *= threads_per_ccx;
+	    }
+	  else
+	    {
+	      /* Account for exclusive L2 and L3 caches.  */
+	      shared += core;
+            }
+	}
+    }
+
+  cpu_features->level1_icache_size = level1_icache_size;
+  cpu_features->level1_dcache_size = level1_dcache_size;
+  cpu_features->level1_dcache_assoc = level1_dcache_assoc;
+  cpu_features->level1_dcache_linesize = level1_dcache_linesize;
+  cpu_features->level2_cache_size = level2_cache_size;
+  cpu_features->level2_cache_assoc = level2_cache_assoc;
+  cpu_features->level2_cache_linesize = level2_cache_linesize;
+  cpu_features->level3_cache_size = level3_cache_size;
+  cpu_features->level3_cache_assoc = level3_cache_assoc;
+  cpu_features->level3_cache_linesize = level3_cache_linesize;
+  cpu_features->level4_cache_size = level4_cache_size;
+
+  /* The default setting for the non_temporal threshold is 3/4 of one
+     thread's share of the chip's cache. For most Intel and AMD processors
+     with an initial release date between 2017 and 2020, a thread's typical
+     share of the cache is from 500 KBytes to 2 MBytes. Using the 3/4
+     threshold leaves 125 KBytes to 500 KBytes of the thread's data
+     in cache after a maximum temporal copy, which will maintain
+     in cache a reasonable portion of the thread's stack and other
+     active data. If the threshold is set higher than one thread's
+     share of the cache, it has a substantial risk of negatively
+     impacting the performance of other threads running on the chip. */
+  unsigned long int non_temporal_threshold = shared * 3 / 4;
+
+#if HAVE_TUNABLES
+  /* NB: The REP MOVSB threshold must be greater than VEC_SIZE * 8.  */
+  unsigned int minimum_rep_movsb_threshold;
+#endif
+  /* NB: The default REP MOVSB threshold is 2048 * (VEC_SIZE / 16).  */
+  unsigned int rep_movsb_threshold;
+  if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
+      && !CPU_FEATURE_PREFERRED_P (cpu_features, Prefer_No_AVX512))
+    {
+      rep_movsb_threshold = 2048 * (64 / 16);
+#if HAVE_TUNABLES
+      minimum_rep_movsb_threshold = 64 * 8;
+#endif
+    }
+  else if (CPU_FEATURE_PREFERRED_P (cpu_features,
+				    AVX_Fast_Unaligned_Load))
+    {
+      rep_movsb_threshold = 2048 * (32 / 16);
+#if HAVE_TUNABLES
+      minimum_rep_movsb_threshold = 32 * 8;
+#endif
+    }
+  else
+    {
+      rep_movsb_threshold = 2048 * (16 / 16);
+#if HAVE_TUNABLES
+      minimum_rep_movsb_threshold = 16 * 8;
+#endif
+    }
+
+  /* The default threshold to use Enhanced REP STOSB.  */
+  unsigned long int rep_stosb_threshold = 2048;
+
+#if HAVE_TUNABLES
+  long int tunable_size;
+
+  tunable_size = TUNABLE_GET (x86_data_cache_size, long int, NULL);
+  /* NB: Ignore the default value 0.  */
+  if (tunable_size != 0)
+    data = tunable_size;
+
+  tunable_size = TUNABLE_GET (x86_shared_cache_size, long int, NULL);
+  /* NB: Ignore the default value 0.  */
+  if (tunable_size != 0)
+    shared = tunable_size;
+
+  tunable_size = TUNABLE_GET (x86_non_temporal_threshold, long int, NULL);
+  /* NB: Ignore the default value 0.  */
+  if (tunable_size != 0)
+    non_temporal_threshold = tunable_size;
+
+  tunable_size = TUNABLE_GET (x86_rep_movsb_threshold, long int, NULL);
+  if (tunable_size > minimum_rep_movsb_threshold)
+    rep_movsb_threshold = tunable_size;
+
+  /* NB: The default value of the x86_rep_stosb_threshold tunable is the
+     same as the default value of __x86_rep_stosb_threshold and the
+     minimum value is fixed.  */
+  rep_stosb_threshold = TUNABLE_GET (x86_rep_stosb_threshold,
+				     long int, NULL);
+
+  TUNABLE_SET_WITH_BOUNDS (x86_data_cache_size, long int, data,
+			   0, (long int) -1);
+  TUNABLE_SET_WITH_BOUNDS (x86_shared_cache_size, long int, shared,
+			   0, (long int) -1);
+  TUNABLE_SET_WITH_BOUNDS (x86_non_temporal_threshold, long int,
+			   non_temporal_threshold, 0, (long int) -1);
+  TUNABLE_SET_WITH_BOUNDS (x86_rep_movsb_threshold, long int,
+			   rep_movsb_threshold,
+			   minimum_rep_movsb_threshold, (long int) -1);
+  TUNABLE_SET_WITH_BOUNDS (x86_rep_stosb_threshold, long int,
+			   rep_stosb_threshold, 1, (long int) -1);
+#endif
+
+  cpu_features->data_cache_size = data;
+  cpu_features->shared_cache_size = shared;
+  cpu_features->non_temporal_threshold = non_temporal_threshold;
+  cpu_features->rep_movsb_threshold = rep_movsb_threshold;
+  cpu_features->rep_stosb_threshold = rep_stosb_threshold;
+}
diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
index 99e7ee08cf..50cb5a15f5 100644
--- a/sysdeps/x86/include/cpu-features.h
+++ b/sysdeps/x86/include/cpu-features.h
@@ -149,6 +149,28 @@  struct cpu_features
   unsigned long int rep_movsb_threshold;
   /* Threshold to use "rep stosb".  */
   unsigned long int rep_stosb_threshold;
+  /* _SC_LEVEL1_ICACHE_SIZE.  */
+  unsigned long int level1_icache_size;
+  /* _SC_LEVEL1_DCACHE_SIZE.  */
+  unsigned long int level1_dcache_size;
+  /* _SC_LEVEL1_DCACHE_ASSOC.  */
+  unsigned long int level1_dcache_assoc;
+  /* _SC_LEVEL1_DCACHE_LINESIZE.  */
+  unsigned long int level1_dcache_linesize;
+  /* _SC_LEVEL2_CACHE_ASSOC.  */
+  unsigned long int level2_cache_size;
+  /* _SC_LEVEL2_DCACHE_ASSOC.  */
+  unsigned long int level2_cache_assoc;
+  /* _SC_LEVEL2_CACHE_LINESIZE.  */
+  unsigned long int level2_cache_linesize;
+  /* /_SC_LEVEL3_CACHE_SIZE.  */
+  unsigned long int level3_cache_size;
+  /* _SC_LEVEL3_CACHE_ASSOC.  */
+  unsigned long int level3_cache_assoc;
+  /* _SC_LEVEL3_CACHE_LINESIZE.  */
+  unsigned long int level3_cache_linesize;
+  /* /_SC_LEVEL4_CACHE_SIZE.  */
+  unsigned long int level4_cache_size;
 };
 
 #if defined (_LIBC) && !IS_IN (nonlib)
-- 
2.29.2