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author | Ruslan Ermilov <ru@nginx.com> | 2017-07-04 18:32:30 +0300 |
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committer | Ruslan Ermilov <ru@nginx.com> | 2017-07-04 18:32:30 +0300 |
commit | d0071f08e88660aab9af84f4210c1a4a32f34980 (patch) | |
tree | 9e0f2266fe6ee4e0e1f4443ba9461f8996540f9d | |
parent | 75c3f8958be4ae7284a46f1d61d79193e6bc5d95 (diff) | |
download | nginx-d0071f08e88660aab9af84f4210c1a4a32f34980.tar.gz |
Slab: fixed small allocations on systems with large pagesize.
Notably, on ppc64 with 64k pagesize, slab 0 (of size 8) requires
128 64-bit elements for bitmasks. The code bogusly assumed that
one uintptr_t is enough for bitmasks plus at least one free slot.
-rw-r--r-- | src/core/ngx_slab.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/src/core/ngx_slab.c b/src/core/ngx_slab.c index 587987023..9e7796d50 100644 --- a/src/core/ngx_slab.c +++ b/src/core/ngx_slab.c @@ -339,11 +339,17 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size) } /* "n" elements for bitmap, plus one requested */ - bitmap[0] = ((uintptr_t) 2 << n) - 1; + + for (i = 0; i < (n + 1) / (8 * sizeof(uintptr_t)); i++) { + bitmap[i] = NGX_SLAB_BUSY; + } + + m = ((uintptr_t) 1 << ((n + 1) % (8 * sizeof(uintptr_t)))) - 1; + bitmap[i] = m; map = (ngx_pagesize >> shift) / (8 * sizeof(uintptr_t)); - for (i = 1; i < map; i++) { + for (i = i + 1; i < map; i++) { bitmap[i] = 0; } @@ -506,13 +512,16 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p) n = 1; } - if (bitmap[0] & ~(((uintptr_t) 1 << n) - 1)) { + i = n / (8 * sizeof(uintptr_t)); + m = ((uintptr_t) 1 << (n % (8 * sizeof(uintptr_t)))) - 1; + + if (bitmap[i] & ~m) { goto done; } map = (ngx_pagesize >> shift) / (8 * sizeof(uintptr_t)); - for (i = 1; i < map; i++) { + for (i = i + 1; i < map; i++) { if (bitmap[i]) { goto done; } |