# HG changeset patch # User Ruslan Ermilov # Date 1499182350 -10800 # Node ID 8c5e3cc21332b3c72747e79efd31c76e75379edb # Parent 94f30939545a6feab63848ea29c701c9e7d9401b 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. diff --git a/src/core/ngx_slab.c b/src/core/ngx_slab.c --- a/src/core/ngx_slab.c +++ b/src/core/ngx_slab.c @@ -339,11 +339,17 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *p } /* "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 *po 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; }