view src/os/unix/ngx_sunpro_amd64.il @ 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 2cd019520210
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/
/ Copyright (C) Igor Sysoev
/ Copyright (C) Nginx, Inc.
/

/ ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock,
/     ngx_atomic_uint_t old, ngx_atomic_uint_t set);
/
/ the arguments are passed in %rdi, %rsi, %rdx
/ the result is returned in the %rax

        .inline ngx_atomic_cmp_set,0
        movq      %rsi, %rax
        lock
        cmpxchgq  %rdx, (%rdi)
        setz      %al
        movzbq    %al, %rax
        .end


/ ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value,
/     ngx_atomic_int_t add);
/
/ the arguments are passed in %rdi, %rsi
/ the result is returned in the %rax

        .inline ngx_atomic_fetch_add,0
        movq      %rsi, %rax
        lock
        xaddq     %rax, (%rdi)
        .end


/ ngx_cpu_pause()
/
/ the "rep; nop" is used instead of "pause" to avoid the "[ PAUSE ]" hardware
/ capability added by linker because Solaris/amd64 does not know about it:
/
/ ld.so.1: nginx: fatal: hardware capability unsupported: 0x2000 [ PAUSE ]

       .inline ngx_cpu_pause,0
       rep; nop
       .end