diff mbox series

[v5,7/7] malloc: Enable huge page support on main arena

Message ID 20211214185806.4109231-8-adhemerval.zanella@linaro.org
State Committed
Headers show
Series malloc: Improve Huge Page support | expand

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

Adhemerval Zanella Dec. 14, 2021, 6:58 p.m. UTC
This patch adds support huge page support on main arena allocation,
enable with tunable glibc.malloc.hugetlb=2.  The patch essentially
disable the __glibc_morecore() sbrk() call (similar when memory
tag does when sbrk() call does not support it) and fallback to
default page size if the memory allocation fails.

Checked on x86_64-linux-gnu.
---
 malloc/arena.c    |  4 ++++
 malloc/malloc.c   | 12 ++++++++++--
 malloc/morecore.c |  4 ----
 3 files changed, 14 insertions(+), 6 deletions(-)

Comments

DJ Delorie Dec. 15, 2021, 4:59 a.m. UTC | #1
LGTM
Reviewed-by: DJ Delorie <dj@redhat.com>

Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> writes:
> diff --git a/malloc/arena.c b/malloc/arena.c
>  # endif
>    TUNABLE_GET (mxfast, size_t, TUNABLE_CALLBACK (set_mxfast));
>    TUNABLE_GET (hugetlb, int32_t, TUNABLE_CALLBACK (set_hugetlb));
> +  if (mp_.hp_pagesize > 0)
> +    /* Force mmap for main arena instead of sbrk, so hugepages are explicitly
> +       used.  */
> +    __always_fail_morecore = true;

Ok.

> diff --git a/malloc/malloc.c b/malloc/malloc.c
>             */
>  
> -	  char *mbrk = sysmalloc_mmap_fallback (&size, nb, old_size, pagesize,
> -						MMAP_AS_MORECORE_SIZE, 0, av);
> +	  char *mbrk = MAP_FAILED;
> +#if HAVE_TUNABLES
> +	  if (mp_.hp_pagesize > 0)
> +	    mbrk = sysmalloc_mmap_fallback (&size, nb, old_size,
> +					    mp_.hp_pagesize, mp_.hp_pagesize,
> +					    mp_.hp_flags, av);
> +#endif
> +	  if (mbrk == MAP_FAILED)
> +	    mbrk = sysmalloc_mmap_fallback (&size, nb, old_size, pagesize,
> +					    MMAP_AS_MORECORE_SIZE, 0, av);

Ok.

> diff --git a/malloc/morecore.c b/malloc/morecore.c
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> -#if defined(SHARED) || defined(USE_MTAG)
>  static bool __always_fail_morecore = false;
> -#endif

Ok.

> @@ -25,10 +23,8 @@ static bool __always_fail_morecore = false;
>  void *
>  __glibc_morecore (ptrdiff_t increment)
>  {
> -#if defined(SHARED) || defined(USE_MTAG)
>    if (__always_fail_morecore)
>      return NULL;
> -#endif

Ok.
diff mbox series

Patch

diff --git a/malloc/arena.c b/malloc/arena.c
index c6d811ff3b..bd09a4fd9e 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -364,6 +364,10 @@  ptmalloc_init (void)
 # endif
   TUNABLE_GET (mxfast, size_t, TUNABLE_CALLBACK (set_mxfast));
   TUNABLE_GET (hugetlb, int32_t, TUNABLE_CALLBACK (set_hugetlb));
+  if (mp_.hp_pagesize > 0)
+    /* Force mmap for main arena instead of sbrk, so hugepages are explicitly
+       used.  */
+    __always_fail_morecore = true;
 #else
   if (__glibc_likely (_environ != NULL))
     {
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 9118306923..5c2bb153f5 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -2740,8 +2740,16 @@  sysmalloc (INTERNAL_SIZE_T nb, mstate av)
              segregated mmap region.
            */
 
-	  char *mbrk = sysmalloc_mmap_fallback (&size, nb, old_size, pagesize,
-						MMAP_AS_MORECORE_SIZE, 0, av);
+	  char *mbrk = MAP_FAILED;
+#if HAVE_TUNABLES
+	  if (mp_.hp_pagesize > 0)
+	    mbrk = sysmalloc_mmap_fallback (&size, nb, old_size,
+					    mp_.hp_pagesize, mp_.hp_pagesize,
+					    mp_.hp_flags, av);
+#endif
+	  if (mbrk == MAP_FAILED)
+	    mbrk = sysmalloc_mmap_fallback (&size, nb, old_size, pagesize,
+					    MMAP_AS_MORECORE_SIZE, 0, av);
 	  if (mbrk != MAP_FAILED)
 	    {
 	      /* We do not need, and cannot use, another sbrk call to find end */
diff --git a/malloc/morecore.c b/malloc/morecore.c
index 8168ef158c..004cd3ead4 100644
--- a/malloc/morecore.c
+++ b/malloc/morecore.c
@@ -15,9 +15,7 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#if defined(SHARED) || defined(USE_MTAG)
 static bool __always_fail_morecore = false;
-#endif
 
 /* Allocate INCREMENT more bytes of data space,
    and return the start of data space, or NULL on errors.
@@ -25,10 +23,8 @@  static bool __always_fail_morecore = false;
 void *
 __glibc_morecore (ptrdiff_t increment)
 {
-#if defined(SHARED) || defined(USE_MTAG)
   if (__always_fail_morecore)
     return NULL;
-#endif
 
   void *result = (void *) __sbrk (increment);
   if (result == (void *) -1)