Mercurial > hg > nginx-quic
view src/os/unix/rfork_thread.S @ 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 <sys/syscall.h> #include <machine/asm.h> /* * rfork_thread(3) - rfork_thread(flags, stack, func, arg); */ #define KERNCALL int $0x80 ENTRY(rfork_thread) push %ebp mov %esp, %ebp push %esi mov 12(%ebp), %esi # the thread stack address sub $4, %esi mov 20(%ebp), %eax # the thread argument mov %eax, (%esi) sub $4, %esi mov 16(%ebp), %eax # the thread start address mov %eax, (%esi) push 8(%ebp) # rfork(2) flags push $0 mov $SYS_rfork, %eax KERNCALL jc error cmp $0, %edx jne child parent: add $8, %esp pop %esi leave ret child: mov %esi, %esp pop %eax call *%eax # call a thread start address ... add $4, %esp push %eax push $0 mov $SYS_exit, %eax # ... and exit(2) after a thread would return KERNCALL error: add $8, %esp pop %esi leave PIC_PROLOGUE /* libc's cerror: jmp PIC_PLT(HIDENAME(cerror)) */ push %eax call PIC_PLT(CNAME(__error)) pop %ecx PIC_EPILOGUE mov %ecx, (%eax) mov $-1, %eax mov $-1, %edx ret