diff options
Diffstat (limited to 'malloc-Improve-MAP_HUGETLB-with-glibc.malloc.hugetlb.patch')
| -rw-r--r-- | malloc-Improve-MAP_HUGETLB-with-glibc.malloc.hugetlb.patch | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/malloc-Improve-MAP_HUGETLB-with-glibc.malloc.hugetlb.patch b/malloc-Improve-MAP_HUGETLB-with-glibc.malloc.hugetlb.patch new file mode 100644 index 0000000..03a9044 --- /dev/null +++ b/malloc-Improve-MAP_HUGETLB-with-glibc.malloc.hugetlb.patch @@ -0,0 +1,50 @@ +From bc6d79f4ae99206e7ec7d6a8c5abf26cdefc8bff Mon Sep 17 00:00:00 2001 +From: Adhemerval Zanella <adhemerval.zanella@linaro.org> +Date: Thu, 23 Nov 2023 14:29:15 -0300 +Subject: [PATCH] malloc: Improve MAP_HUGETLB with glibc.malloc.hugetlb=2 + +Even for explicit large page support, allocation might use mmap without +the hugepage bit set if the requested size is smaller than +mmap_threshold. For this case where mmap is issued, MAP_HUGETLB is set +iff the allocation size is larger than the used large page. + +To force such allocations to use large pages, also tune the mmap_threhold +(if it is not explicit set by a tunable). This forces allocation to +follow the sbrk path, which will fall back to mmap (which will try large +pages before galling back to default mmap). + +Checked on x86_64-linux-gnu. +Reviewed-by: DJ Delorie <dj@redhat.com> +Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org> + +Conflict: this adapt the context from the origin commit. +--- + malloc/arena.c | 12 +++++++++--- + 1 file changed, 9 insertions(+), 3 deletions(-) + +diff --git a/malloc/arena.c b/malloc/arena.c +index f8e425e1..33dbc5ae 100644 +--- a/malloc/arena.c ++++ b/malloc/arena.c +@@ -366,9 +366,15 @@ ptmalloc_init (void) + 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; ++ { ++ /* Force mmap for main arena instead of sbrk, so MAP_HUGETLB is always ++ tried. Also tune the mmap threshold, so allocation smaller than the ++ large page will also try to use large pages by falling back ++ to sysmalloc_mmap_fallback on sysmalloc. */ ++ if (!TUNABLE_IS_INITIALIZED (mmap_threshold)) ++ do_set_mmap_threshold (mp_.hp_pagesize); ++ __always_fail_morecore = true; ++ } + #else + if (__glibc_likely (_environ != NULL)) + { +-- +2.33.0 + |