Mercurial > hg > nginx-quic
view src/core/ngx_queue.c @ 5718:c46657e391a3
Core: slab allocator free pages defragmentation.
Large allocations from a slab pool result in free page blocks being fragmented,
eventually leading to a situation when no further allocation larger than a page
size are possible from the pool. While this isn't a problem for nginx itself,
it is known to be bad for various 3rd party modules. Fix is to merge adjacent
blocks of free pages in the ngx_slab_free_pages() function.
Prodded by Wandenberg Peixoto and Yichun Zhang.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 03 Jun 2014 17:53:03 +0400 |
parents | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> /* * find the middle queue element if the queue has odd number of elements * or the first element of the queue's second part otherwise */ ngx_queue_t * ngx_queue_middle(ngx_queue_t *queue) { ngx_queue_t *middle, *next; middle = ngx_queue_head(queue); if (middle == ngx_queue_last(queue)) { return middle; } next = ngx_queue_head(queue); for ( ;; ) { middle = ngx_queue_next(middle); next = ngx_queue_next(next); if (next == ngx_queue_last(queue)) { return middle; } next = ngx_queue_next(next); if (next == ngx_queue_last(queue)) { return middle; } } } /* the stable insertion sort */ void ngx_queue_sort(ngx_queue_t *queue, ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *)) { ngx_queue_t *q, *prev, *next; q = ngx_queue_head(queue); if (q == ngx_queue_last(queue)) { return; } for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) { prev = ngx_queue_prev(q); next = ngx_queue_next(q); ngx_queue_remove(q); do { if (cmp(prev, q) <= 0) { break; } prev = ngx_queue_prev(prev); } while (prev != ngx_queue_sentinel(queue)); ngx_queue_insert_after(prev, q); } }