diff options
Diffstat (limited to 'malloc-hugepage-0003-malloc-Move-mmap-logic-to-its-own-function.patch')
| -rw-r--r-- | malloc-hugepage-0003-malloc-Move-mmap-logic-to-its-own-function.patch | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/malloc-hugepage-0003-malloc-Move-mmap-logic-to-its-own-function.patch b/malloc-hugepage-0003-malloc-Move-mmap-logic-to-its-own-function.patch new file mode 100644 index 0000000..5b1768b --- /dev/null +++ b/malloc-hugepage-0003-malloc-Move-mmap-logic-to-its-own-function.patch @@ -0,0 +1,205 @@ +From 6cc3ccc67e0dda654fc839377af2818a296f0007 Mon Sep 17 00:00:00 2001 +From: Adhemerval Zanella <adhemerval.zanella@linaro.org> +Date: Mon, 16 Aug 2021 11:14:20 -0300 +Subject: [PATCH 3/7] malloc: Move mmap logic to its own function + +So it can be used with different pagesize and flags. + +Reviewed-by: DJ Delorie <dj@redhat.com> +--- + malloc/malloc.c | 164 ++++++++++++++++++++++++++---------------------- + 1 file changed, 88 insertions(+), 76 deletions(-) + +diff --git a/malloc/malloc.c b/malloc/malloc.c +index 57db4dd9a5..6b6ec53db1 100644 +--- a/malloc/malloc.c ++++ b/malloc/malloc.c +@@ -2412,6 +2412,85 @@ do_check_malloc_state (mstate av) + be extended or replaced. + */ + ++static void * ++sysmalloc_mmap (INTERNAL_SIZE_T nb, size_t pagesize, int extra_flags, mstate av) ++{ ++ long int size; ++ ++ /* ++ Round up size to nearest page. For mmapped chunks, the overhead is one ++ SIZE_SZ unit larger than for normal chunks, because there is no ++ following chunk whose prev_size field could be used. ++ ++ See the front_misalign handling below, for glibc there is no need for ++ further alignments unless we have have high alignment. ++ */ ++ if (MALLOC_ALIGNMENT == CHUNK_HDR_SZ) ++ size = ALIGN_UP (nb + SIZE_SZ, pagesize); ++ else ++ size = ALIGN_UP (nb + SIZE_SZ + MALLOC_ALIGN_MASK, pagesize); ++ ++ /* Don't try if size wraps around 0. */ ++ if ((unsigned long) (size) <= (unsigned long) (nb)) ++ return MAP_FAILED; ++ ++ char *mm = (char *) MMAP (0, size, ++ mtag_mmap_flags | PROT_READ | PROT_WRITE, ++ extra_flags); ++ if (mm == MAP_FAILED) ++ return mm; ++ ++ madvise_thp (mm, size); ++ ++ /* ++ The offset to the start of the mmapped region is stored in the prev_size ++ field of the chunk. This allows us to adjust returned start address to ++ meet alignment requirements here and in memalign(), and still be able to ++ compute proper address argument for later munmap in free() and realloc(). ++ */ ++ ++ INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of new space */ ++ ++ if (MALLOC_ALIGNMENT == CHUNK_HDR_SZ) ++ { ++ /* For glibc, chunk2mem increases the address by CHUNK_HDR_SZ and ++ MALLOC_ALIGN_MASK is CHUNK_HDR_SZ-1. Each mmap'ed area is page ++ aligned and therefore definitely MALLOC_ALIGN_MASK-aligned. */ ++ assert (((INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK) == 0); ++ front_misalign = 0; ++ } ++ else ++ front_misalign = (INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK; ++ ++ mchunkptr p; /* the allocated/returned chunk */ ++ ++ if (front_misalign > 0) ++ { ++ ptrdiff_t correction = MALLOC_ALIGNMENT - front_misalign; ++ p = (mchunkptr) (mm + correction); ++ set_prev_size (p, correction); ++ set_head (p, (size - correction) | IS_MMAPPED); ++ } ++ else ++ { ++ p = (mchunkptr) mm; ++ set_prev_size (p, 0); ++ set_head (p, size | IS_MMAPPED); ++ } ++ ++ /* update statistics */ ++ int new = atomic_exchange_and_add (&mp_.n_mmaps, 1) + 1; ++ atomic_max (&mp_.max_n_mmaps, new); ++ ++ unsigned long sum; ++ sum = atomic_exchange_and_add (&mp_.mmapped_mem, size) + size; ++ atomic_max (&mp_.max_mmapped_mem, sum); ++ ++ check_chunk (av, p); ++ ++ return chunk2mem (p); ++} ++ + static void * + sysmalloc (INTERNAL_SIZE_T nb, mstate av) + { +@@ -2449,81 +2528,10 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av) + || ((unsigned long) (nb) >= (unsigned long) (mp_.mmap_threshold) + && (mp_.n_mmaps < mp_.n_mmaps_max))) + { +- char *mm; /* return value from mmap call*/ +- +- try_mmap: +- /* +- Round up size to nearest page. For mmapped chunks, the overhead +- is one SIZE_SZ unit larger than for normal chunks, because there +- is no following chunk whose prev_size field could be used. +- +- See the front_misalign handling below, for glibc there is no +- need for further alignments unless we have have high alignment. +- */ +- if (MALLOC_ALIGNMENT == CHUNK_HDR_SZ) +- size = ALIGN_UP (nb + SIZE_SZ, pagesize); +- else +- size = ALIGN_UP (nb + SIZE_SZ + MALLOC_ALIGN_MASK, pagesize); ++ char *mm = sysmalloc_mmap (nb, pagesize, 0, av); ++ if (mm != MAP_FAILED) ++ return mm; + tried_mmap = true; +- +- /* Don't try if size wraps around 0 */ +- if ((unsigned long) (size) > (unsigned long) (nb)) +- { +- mm = (char *) (MMAP (0, size, +- mtag_mmap_flags | PROT_READ | PROT_WRITE, 0)); +- +- if (mm != MAP_FAILED) +- { +- madvise_thp (mm, size); +- +- /* +- The offset to the start of the mmapped region is stored +- in the prev_size field of the chunk. This allows us to adjust +- returned start address to meet alignment requirements here +- and in memalign(), and still be able to compute proper +- address argument for later munmap in free() and realloc(). +- */ +- +- if (MALLOC_ALIGNMENT == CHUNK_HDR_SZ) +- { +- /* For glibc, chunk2mem increases the address by +- CHUNK_HDR_SZ and MALLOC_ALIGN_MASK is +- CHUNK_HDR_SZ-1. Each mmap'ed area is page +- aligned and therefore definitely +- MALLOC_ALIGN_MASK-aligned. */ +- assert (((INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK) == 0); +- front_misalign = 0; +- } +- else +- front_misalign = (INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK; +- if (front_misalign > 0) +- { +- correction = MALLOC_ALIGNMENT - front_misalign; +- p = (mchunkptr) (mm + correction); +- set_prev_size (p, correction); +- set_head (p, (size - correction) | IS_MMAPPED); +- } +- else +- { +- p = (mchunkptr) mm; +- set_prev_size (p, 0); +- set_head (p, size | IS_MMAPPED); +- } +- +- /* update statistics */ +- +- int new = atomic_exchange_and_add (&mp_.n_mmaps, 1) + 1; +- atomic_max (&mp_.max_n_mmaps, new); +- +- unsigned long sum; +- sum = atomic_exchange_and_add (&mp_.mmapped_mem, size) + size; +- atomic_max (&mp_.max_mmapped_mem, sum); +- +- check_chunk (av, p); +- +- return chunk2mem (p); +- } +- } + } + + /* There are no usable arenas and mmap also failed. */ +@@ -2600,8 +2608,12 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av) + } + } + else if (!tried_mmap) +- /* We can at least try to use to mmap memory. */ +- goto try_mmap; ++ { ++ /* We can at least try to use to mmap memory. */ ++ char *mm = sysmalloc_mmap (nb, pagesize, 0, av); ++ if (mm != MAP_FAILED) ++ return mm; ++ } + } + else /* av == main_arena */ + +-- +2.33.0 + |