From: Jason Baron <jbaron@akamai.com>
To: peterz@infradead.org, mingo@redhat.com, viro@zeniv.linux.org.uk
Cc: akpm@linux-foundation.org, normalperson@yhbt.net,
davidel@xmailserver.org, mtk.manpages@gmail.com,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-api@vger.kernel.org
Subject: [PATCH v2 0/2] Add epoll round robin wakeup mode
Date: Tue, 17 Feb 2015 19:33:36 +0000 (GMT) [thread overview]
Message-ID: <cover.1424200151.git.jbaron@akamai.com> (raw)
When we are sharing a wakeup source among multiple epoll fds, we end up with
thundering herd wakeups, since there is currently no way to add to the
wakeup source exclusively. This series introduces 2 new epoll flags,
EPOLLEXCLUSIVE for adding to a wakeup source exclusively. And EPOLLROUNDROBIN
which is to be used in conjunction to EPOLLEXCLUSIVE to evenly
distribute the wakeups. This patch was originally motivated by a desire to
improve wakeup balance and cpu usage for a listen socket() shared amongst
multiple epoll fd sets.
See: http://lwn.net/Articles/632590/ for previous test program and testing
resutls.
Epoll manpage text:
EPOLLEXCLUSIVE
Provides exclusive wakeups when attaching multiple epoll fds to a
shared wakeup source. Must be specified with an EPOLL_CTL_ADD operation.
EPOLLROUNDROBIN
Provides balancing for exclusive wakeups when attaching multiple epoll
fds to a shared wakeup soruce. Depends on EPOLLEXCLUSIVE being set and
must be specified with an EPOLL_CTL_ADD operation.
Thanks,
-Jason
Jason Baron (2):
sched/wait: add round robin wakeup mode
epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN
fs/eventpoll.c | 25 ++++++++++++++++++++-----
include/linux/wait.h | 11 +++++++++++
include/uapi/linux/eventpoll.h | 6 ++++++
kernel/sched/wait.c | 10 ++++++++--
4 files changed, 45 insertions(+), 7 deletions(-)
--
1.8.2.rc2
next reply other threads:[~2015-02-17 19:33 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-17 19:33 Jason Baron [this message]
2015-02-17 19:33 ` [PATCH v2 1/2] sched/wait: add round robin wakeup mode Jason Baron
2015-02-17 19:33 ` [PATCH v2 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN Jason Baron
2015-02-18 8:07 ` Ingo Molnar
2015-02-18 15:42 ` Jason Baron
2015-02-18 16:33 ` Ingo Molnar
2015-02-18 17:38 ` Jason Baron
2015-02-18 17:45 ` Ingo Molnar
2015-02-18 17:51 ` Ingo Molnar
2015-02-18 22:18 ` Eric Wong
2015-02-19 3:26 ` Jason Baron
2015-02-22 0:24 ` Eric Wong
2015-02-25 15:48 ` Jason Baron
2015-02-18 23:12 ` Andy Lutomirski
[not found] ` <CAPh34mcPNQELwZCDTHej+HK=bpWgJ=jb1LeCtKoUHVgoDJOJoQ@mail.gmail.com>
2015-02-27 22:24 ` Jason Baron
2015-02-17 19:46 ` [PATCH v2 0/2] Add epoll round robin wakeup mode Andy Lutomirski
2015-02-17 20:33 ` Jason Baron
2015-02-17 21:09 ` Andy Lutomirski
2015-02-18 3:15 ` Jason Baron
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