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.
diff --git a/src/event/modules/ngx_epoll_module.c b/src/event/modules/ngx_epoll_module.c
index df5bf89..31c10c6 100644
--- a/src/event/modules/ngx_epoll_module.c
+++ b/src/event/modules/ngx_epoll_module.c
@@ -86,6 +86,7 @@
typedef struct {
ngx_uint_t events;
+ ngx_uint_t aio_requests;
} ngx_epoll_conf_t;
@@ -133,6 +134,13 @@
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 @@
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 @@
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 @@
#if (NGX_HAVE_FILE_AIO)
- ngx_epoll_aio_init(cycle);
+ ngx_epoll_aio_init(cycle, epcf);
#endif
}
@@ -794,6 +802,7 @@
}
epcf->events = NGX_CONF_UNSET;
+ epcf->aio_requests = NGX_CONF_UNSET;
return epcf;
}
@@ -805,6 +814,7 @@
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;
}