Mercurial > hg > nginx
changeset 6635:6acaa638fa07
Events: support for EPOLLEXCLUSIVE.
This flag appeared in Linux 4.5 and is useful for avoiding thundering herd
problem.
The current Linux kernel implementation walks the list of exclusive waiters,
and queues an event to each epfd, until it finds the first waiter that has
threads blocked on it via epoll_wait().
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Fri, 15 Jul 2016 15:18:57 +0300 |
parents | 18f6120e3b7a |
children | ea284434db0f |
files | auto/modules auto/os/linux src/event/modules/ngx_epoll_module.c src/event/ngx_event.c src/event/ngx_event.h |
diffstat | 5 files changed, 59 insertions(+), 4 deletions(-) [+] |
line wrap: on
line diff
--- a/auto/modules +++ b/auto/modules @@ -43,6 +43,7 @@ fi if [ $NGX_TEST_BUILD_EPOLL = YES ]; then have=NGX_HAVE_EPOLL . auto/have have=NGX_HAVE_EPOLLRDHUP . auto/have + have=NGX_HAVE_EPOLLEXCLUSIVE . auto/have have=NGX_HAVE_EVENTFD . auto/have have=NGX_TEST_BUILD_EPOLL . auto/have EVENT_MODULES="$EVENT_MODULES $EPOLL_MODULE"
--- a/auto/os/linux +++ b/auto/os/linux @@ -70,6 +70,22 @@ if [ $ngx_found = yes ]; then ee.data.ptr = NULL; epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)" . auto/feature + + + # EPOLLEXCLUSIVE appeared in Linux 4.5, glibc 2.24 + + ngx_feature="EPOLLEXCLUSIVE" + ngx_feature_name="NGX_HAVE_EPOLLEXCLUSIVE" + ngx_feature_run=no + ngx_feature_incs="#include <sys/epoll.h>" + ngx_feature_path= + ngx_feature_libs= + ngx_feature_test="int efd = 0, fd = 0; + struct epoll_event ee; + ee.events = EPOLLIN|EPOLLEXCLUSIVE; + ee.data.ptr = NULL; + epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)" + . auto/feature fi
--- a/src/event/modules/ngx_epoll_module.c +++ b/src/event/modules/ngx_epoll_module.c @@ -27,6 +27,7 @@ #define EPOLLRDHUP 0x2000 +#define EPOLLEXCLUSIVE 0x10000000 #define EPOLLONESHOT 0x40000000 #define EPOLLET 0x80000000 @@ -610,6 +611,12 @@ ngx_epoll_add_event(ngx_event_t *ev, ngx op = EPOLL_CTL_ADD; } +#if (NGX_HAVE_EPOLLEXCLUSIVE && NGX_HAVE_EPOLLRDHUP) + if (flags & NGX_EXCLUSIVE_EVENT) { + events &= ~EPOLLRDHUP; + } +#endif + ee.events = events | (uint32_t) flags; ee.data.ptr = (void *) ((uintptr_t) c | ev->instance);
--- a/src/event/ngx_event.c +++ b/src/event/ngx_event.c @@ -822,15 +822,38 @@ ngx_event_process_init(ngx_cycle_t *cycl rev->handler = (c->type == SOCK_STREAM) ? ngx_event_accept : ngx_event_recvmsg; - if (ngx_use_accept_mutex #if (NGX_HAVE_REUSEPORT) - && !ls[i].reuseport + + if (ls[i].reuseport) { + if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) { + return NGX_ERROR; + } + + continue; + } + #endif - ) - { + + if (ngx_use_accept_mutex) { continue; } +#if (NGX_HAVE_EPOLLEXCLUSIVE) + + if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) + && ccf->worker_processes > 1) + { + if (ngx_add_event(rev, NGX_READ_EVENT, NGX_EXCLUSIVE_EVENT) + == NGX_ERROR) + { + return NGX_ERROR; + } + + continue; + } + +#endif + if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) { return NGX_ERROR; }
--- a/src/event/ngx_event.h +++ b/src/event/ngx_event.h @@ -367,6 +367,9 @@ extern ngx_uint_t ngx_use_epo #define NGX_ONESHOT_EVENT EPOLLONESHOT #endif +#if (NGX_HAVE_EPOLLEXCLUSIVE) +#define NGX_EXCLUSIVE_EVENT EPOLLEXCLUSIVE +#endif #elif (NGX_HAVE_POLL) @@ -395,6 +398,11 @@ extern ngx_uint_t ngx_use_epo #endif +#if (NGX_TEST_BUILD_EPOLL) +#define NGX_EXCLUSIVE_EVENT 0 +#endif + + #ifndef NGX_CLEAR_EVENT #define NGX_CLEAR_EVENT 0 /* dummy declaration */ #endif