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| author | Pavel Tatashin <pasha.tatashin@oracle.com> | 2017-07-06 15:39:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-06 16:24:33 -0700 |
| commit | 3749a8f008eac3355a9e50b366ba08317a7e9cf8 (patch) | |
| tree | 448dc6eaf19a3838cdc2ab497c529729168def2b /mm/page_alloc.c | |
| parent | f7fb506fef6e8701bdb0ea7bb4f01148efd7416c (diff) | |
| download | linux-3749a8f008eac3355a9e50b366ba08317a7e9cf8.tar.gz | |
mm: zero hash tables in allocator
Add a new flag HASH_ZERO which when provided grantees that the hash table that is returned by alloc_large_system_hash() is zeroed. In most cases that is what is needed by the caller. Use page level allocator's __GFP_ZERO flags to zero the memory. It is using memset() which is efficient method to zero memory and is optimized for most platforms. Link: http://lkml.kernel.org/r/1488432825-92126-3-git-send-email-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Babu Moger <babu.moger@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 387f20db217c..34240e2a0583 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7198,6 +7198,7 @@ void *__init alloc_large_system_hash(const char *tablename, unsigned long long max = high_limit; unsigned long log2qty, size; void *table = NULL; + gfp_t gfp_flags; /* allow the kernel cmdline to have a say */ if (!numentries) { @@ -7242,12 +7243,17 @@ void *__init alloc_large_system_hash(const char *tablename, log2qty = ilog2(numentries); + /* + * memblock allocator returns zeroed memory already, so HASH_ZERO is + * currently not used when HASH_EARLY is specified. + */ + gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC; do { size = bucketsize << log2qty; if (flags & HASH_EARLY) table = memblock_virt_alloc_nopanic(size, 0); else if (hashdist) - table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); + table = __vmalloc(size, gfp_flags, PAGE_KERNEL); else { /* * If bucketsize is not a power-of-two, we may free @@ -7255,8 +7261,8 @@ void *__init alloc_large_system_hash(const char *tablename, * alloc_pages_exact() automatically does */ if (get_order(size) < MAX_ORDER) { - table = alloc_pages_exact(size, GFP_ATOMIC); - kmemleak_alloc(table, size, 1, GFP_ATOMIC); + table = alloc_pages_exact(size, gfp_flags); + kmemleak_alloc(table, size, 1, gfp_flags); } } } while (!table && size > PAGE_SIZE && --log2qty); |