From: Eric Wong <normalperson@yhbt.net>
To: Jason Baron <jbaron@akamai.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
Linux API <linux-api@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Davide Libenzi <davidel@xmailserver.org>,
Michael Kerrisk-manpages <mtk.manpages@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN
Date: Tue, 10 Feb 2015 19:32:47 +0000 [thread overview]
Message-ID: <20150210193247.GA12953@dcvr.yhbt.net> (raw)
In-Reply-To: <54DA592A.3050102@akamai.com>
Jason Baron <jbaron@akamai.com> wrote:
> On 02/09/2015 11:49 PM, Eric Wong wrote:
> > Do you have a userland use case to share?
>
> I've been trying to describe the use case, maybe I haven't been doing a good
> job :(
Sorry, I meant if you had any public code.
Anyways, I've restarted work on another project which I'll hopefully be
able to share in a few weeks which might be a good public candidate for
epoll performance testing.
> > Did you try my suggestion of using a dedicated thread (or thread pool)
> > which does nothing but loop on accept() + EPOLL_CTL_ADD?
> >
> > Those dedicated threads could do its own round-robin in userland to pick
> > a different epollfd to call EPOLL_CTL_ADD on.
>
> Thanks for your suggestion! I'm not actively working on the user-space
> code here, but I will pass it along.
>
> I would prefer though not to have to context switch the 'accept' thread
> on and off the cpu every time there is a new connection. So the approach
> suggested here essentially moves this dedicated thread (threads), down
> into the kernel and avoids the creation of these threads entirely.
For cmogstored, I stopped using TCP_DEFER_ACCEPT when using the
dedicated thread. This approach offloads to epoll and ends up giving
similar behavior to what used to be infinite in TCP_DEFER_ACCEPT in
Linux <= 2.6.31
next prev parent reply other threads:[~2015-02-10 19:32 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-09 20:05 [PATCH 0/2] Add epoll round robin wakeup mode Jason Baron
2015-02-09 20:05 ` [PATCH 1/2] sched/wait: add " Jason Baron
2015-02-09 20:26 ` Michael Kerrisk
2015-02-09 21:50 ` Peter Zijlstra
2015-02-10 4:06 ` Jason Baron
2015-02-10 9:03 ` Peter Zijlstra
2015-02-10 15:59 ` Jason Baron
2015-02-10 16:11 ` Peter Zijlstra
2015-02-09 20:06 ` [PATCH 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN Jason Baron
2015-02-09 20:18 ` Andy Lutomirski
2015-02-09 21:32 ` Jason Baron
2015-02-09 22:45 ` Andy Lutomirski
2015-02-10 3:59 ` Jason Baron
2015-02-10 4:49 ` Eric Wong
2015-02-10 19:16 ` Jason Baron
2015-02-10 19:32 ` Eric Wong [this message]
2015-02-09 20:27 ` Michael Kerrisk
2015-02-09 20:25 ` [PATCH 0/2] Add epoll round robin wakeup mode Michael Kerrisk
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