lkml.org 
[lkml]   [2015]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH] epoll: add exclusive wakeups flag
Date
Hi,

Re-post of an old series addressing thundering herd issues when sharing
an event source fd amongst multiple epoll fds. Last posting was here
for reference: https://lkml.org/lkml/2015/2/25/56

The patch herein drops the core scheduler 'rotate' changes I had previously
proposed as this patch seems performant without those.

I was prompted to re-post this because Madars Vitolins reported some good
speedups with this patch using Enduro/X application. His writeup is here:
https://mvitolin.wordpress.com/2015/12/05/endurox-testing-epollexclusive-flag/

Thanks,

-Jason

Sample epoll_clt text:

EPOLLEXCLUSIVE
Sets an exclusive wakeup mode for the epfd file descriptor that is
being attached to the target file descriptor, fd. Thus, when an
event occurs and multiple epfd file descriptors are attached to the
same target file using EPOLLEXCLUSIVE, one or more epfds will receive
an event with epoll_wait(2). The default in this scenario (when
EPOLLEXCLUSIVE is not set) is for all epfds to receive an event.
EPOLLEXLUSVIE may only be specified with the op EPOLL_CTL_ADD.

Jason Baron (1):
epoll: add EPOLLEXCLUSIVE flag

fs/eventpoll.c | 24 +++++++++++++++++++++---
include/uapi/linux/eventpoll.h | 3 +++
2 files changed, 24 insertions(+), 3 deletions(-)

--
2.6.1



\
 
 \ /
  Last update: 2015-12-08 04:41    [W:0.102 / U:0.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site