diff mbox

x86: Add cache info to cpu_features

Message ID 20170524032917.GA18498@gmail.com
State New, archived
Headers

Commit Message

H.J. Lu May 24, 2017, 3:29 a.m. UTC 
  This patch adds cache info to cpu_features to support tunables for both
cache info as well as CPU features in a single x86 namespace.  Since
init_cacheinfo is in libc.so and cpu_features is in ld.so, cache info
and CPU features must be in a place for tunables.

Any comments?

H.J.
---
	* sysdeps/x86/cacheinfo.c (init_cacheinfo): Use data_size,
	shared_size and non_temporal_threshold from cpu_features if
	they aren't not zero.
	* sysdeps/x86/cpu-features.h (cache_info): New.
	(cpu_features): Add cache.
---
 sysdeps/x86/cacheinfo.c    | 11 ++++++++++-
 sysdeps/x86/cpu-features.h | 13 +++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
index 12ffeef..321fbb6 100644
--- a/sysdeps/x86/cacheinfo.c
+++ b/sysdeps/x86/cacheinfo.c
@@ -745,6 +745,9 @@  intel_bug_no_cache_info:
 #endif
     }
 
+  if (cpu_features->cache.data_size != 0)
+    data = cpu_features->cache.data_size;
+
   if (data > 0)
     {
       __x86_raw_data_cache_size_half = data / 2;
@@ -755,6 +758,9 @@  intel_bug_no_cache_info:
       __x86_data_cache_size = data;
     }
 
+  if (cpu_features->cache.shared_size != 0)
+    shared = cpu_features->cache.shared_size;
+
   if (shared > 0)
     {
       __x86_raw_shared_cache_size_half = shared / 2;
@@ -768,7 +774,10 @@  intel_bug_no_cache_info:
   /* The large memcpy micro benchmark in glibc shows that 6 times of
      shared cache size is the approximate value above which non-temporal
      store becomes faster.  */
-  __x86_shared_non_temporal_threshold = __x86_shared_cache_size * 6;
+  __x86_shared_non_temporal_threshold
+    = (cpu_features->cache.non_temporal_threshold != 0
+       ? cpu_features->cache.non_temporal_threshold
+       : __x86_shared_cache_size * 6);
 }
 
 #endif
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index 31c7c80..f428dca 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -185,6 +185,18 @@ 
 
 #else	/* __ASSEMBLER__ */
 
+struct cache_info
+{
+  /* Data cache size for use in memory and string routines, typically
+     L1 size.  */
+  long int data_size;
+  /* Shared cache size for use in memory and string routines, typically
+     L2 or L3 size.  */
+  long int shared_size;
+  /* Threshold to use non temporal store.  */
+  long int non_temporal_threshold;
+};
+
 enum
   {
     COMMON_CPUID_INDEX_1 = 0,
@@ -214,6 +226,7 @@  struct cpu_features
   unsigned int family;
   unsigned int model;
   unsigned int feature[FEATURE_INDEX_MAX];
+  struct cache_info cache;
 };
 
 /* Used from outside of glibc to get access to the CPU features