From 7478c9959ae409f7b3d63146943575d6ee745352 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Fri, 13 Aug 2021 10:06:04 -0300 Subject: malloc: Add THP/madvise support for sbrk To increase effectiveness with Transparent Huge Page with madvise, the large page size is use instead page size for sbrk increment for the main arena. Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie --- malloc/malloc.c | 34 +++++++++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 5 deletions(-) (limited to 'malloc') diff --git a/malloc/malloc.c b/malloc/malloc.c index c75841b..57db4dd 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -2023,6 +2023,16 @@ madvise_thp (void *p, INTERNAL_SIZE_T size) not active. */ if (mp_.thp_pagesize == 0 || size < mp_.thp_pagesize) return; + + /* Linux requires the input address to be page-aligned, and unaligned + inputs happens only for initial data segment. */ + if (__glibc_unlikely (!PTR_IS_ALIGNED (p, GLRO (dl_pagesize)))) + { + void *q = PTR_ALIGN_DOWN (p, GLRO (dl_pagesize)); + size += PTR_DIFF (p, q); + p = q; + } + __madvise (p, size, MADV_HUGEPAGE); #endif } @@ -2609,14 +2619,25 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av) size -= old_size; /* - Round to a multiple of page size. + Round to a multiple of page size or huge page size. If MORECORE is not contiguous, this ensures that we only call it with whole-page arguments. And if MORECORE is contiguous and this is not first time through, this preserves page-alignment of previous calls. Otherwise, we correct to page-align below. */ - size = ALIGN_UP (size, pagesize); +#if HAVE_TUNABLES && defined (MADV_HUGEPAGE) + /* Defined in brk.c. */ + extern void *__curbrk; + if (__glibc_unlikely (mp_.thp_pagesize != 0)) + { + uintptr_t top = ALIGN_UP ((uintptr_t) __curbrk + size, + mp_.thp_pagesize); + size = top - (uintptr_t) __curbrk; + } + else +#endif + size = ALIGN_UP (size, GLRO(dl_pagesize)); /* Don't try to call MORECORE if argument is so big as to appear @@ -2899,10 +2920,8 @@ systrim (size_t pad, mstate av) long released; /* Amount actually released */ char *current_brk; /* address returned by pre-check sbrk call */ char *new_brk; /* address returned by post-check sbrk call */ - size_t pagesize; long top_area; - pagesize = GLRO (dl_pagesize); top_size = chunksize (av->top); top_area = top_size - MINSIZE - 1; @@ -2910,7 +2929,12 @@ systrim (size_t pad, mstate av) return 0; /* Release in pagesize units and round down to the nearest page. */ - extra = ALIGN_DOWN(top_area - pad, pagesize); +#if HAVE_TUNABLES && defined (MADV_HUGEPAGE) + if (__glibc_unlikely (mp_.thp_pagesize != 0)) + extra = ALIGN_DOWN (top_area - pad, mp_.thp_pagesize); + else +#endif + extra = ALIGN_DOWN (top_area - pad, GLRO(dl_pagesize)); if (extra == 0) return 0; -- cgit v1.1