The "worker_aio_requests" directive.

The default value is 32 AIO simultaneous requests per worker. Previously
they were hardcoded to 1024, and it was too large, since Linux allocated
them early on io_setup(), but not on request itself. So with default value
of /proc/sys/fs/aio-max-nr equal to 65536 only 64 worker processes could
be run simultaneously. 32 AIO requests are enough for modern disks even if
server runs only 1 worker.
This commit is contained in:
Igor Sysoev 2011-09-20 07:30:09 +00:00
parent a823c550e4
commit c8df23cb29

View File

@ -86,6 +86,7 @@ int eventfd(u_int initval)
typedef struct {
ngx_uint_t events;
ngx_uint_t aio_requests;
} ngx_epoll_conf_t;
@ -133,6 +134,13 @@ static ngx_command_t ngx_epoll_commands[] = {
offsetof(ngx_epoll_conf_t, events),
NULL },
{ ngx_string("worker_aio_requests"),
NGX_EVENT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
0,
offsetof(ngx_epoll_conf_t, aio_requests),
NULL },
ngx_null_command
};
@ -207,7 +215,7 @@ io_getevents(aio_context_t ctx, long min_nr, long nr, struct io_event *events,
static void
ngx_epoll_aio_init(ngx_cycle_t *cycle)
ngx_epoll_aio_init(ngx_cycle_t *cycle, ngx_epoll_conf_t *epcf)
{
int n;
struct epoll_event ee;
@ -232,7 +240,7 @@ ngx_epoll_aio_init(ngx_cycle_t *cycle)
goto failed;
}
if (io_setup(1024, &ngx_aio_ctx) == -1) {
if (io_setup(epcf->aio_requests, &ngx_aio_ctx) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"io_setup() failed");
goto failed;
@ -294,7 +302,7 @@ ngx_epoll_init(ngx_cycle_t *cycle, ngx_msec_t timer)
#if (NGX_HAVE_FILE_AIO)
ngx_epoll_aio_init(cycle);
ngx_epoll_aio_init(cycle, epcf);
#endif
}
@ -794,6 +802,7 @@ ngx_epoll_create_conf(ngx_cycle_t *cycle)
}
epcf->events = NGX_CONF_UNSET;
epcf->aio_requests = NGX_CONF_UNSET;
return epcf;
}
@ -805,6 +814,7 @@ ngx_epoll_init_conf(ngx_cycle_t *cycle, void *conf)
ngx_epoll_conf_t *epcf = conf;
ngx_conf_init_uint_value(epcf->events, 512);
ngx_conf_init_uint_value(epcf->aio_requests, 32);
return NGX_CONF_OK;
}