about summary refs log tree commit diff
path: root/malloc
diff options
context:
space:
mode:
authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-08-30 14:01:00 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-12-15 17:35:39 -0300
commit0f982c182760bd7689769ee7590df592d0a132c0 (patch)
treef538197b6d1f3d2bd4eda217fccb4c824d3b5929 /malloc
parent0849eed45daabf30a02c153695041597d6d43b2d (diff)
downloadglibc-0f982c182760bd7689769ee7590df592d0a132c0.tar.gz
glibc-0f982c182760bd7689769ee7590df592d0a132c0.tar.xz
glibc-0f982c182760bd7689769ee7590df592d0a132c0.zip
malloc: Enable huge page support on main arena
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.

Reviewed-by: DJ Delorie <dj@redhat.com>
Diffstat (limited to 'malloc')
-rw-r--r--malloc/arena.c4
-rw-r--r--malloc/malloc.c12
-rw-r--r--malloc/morecore.c4
3 files changed, 14 insertions, 6 deletions
diff --git a/malloc/arena.c b/malloc/arena.c
index e1852f8597..3ed4ef3f05 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, size_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 32050be4cc..b67f2c84ee 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -2741,8 +2741,16 @@ 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)