From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>, John Stultz <john.stultz@linaro.org>,
Ingo Molnar <mingo@redhat.com>,
lkml <linux-kernel@vger.kernel.org>,
Dmitry Shmidt <dimitrysh@google.com>,
Rom Lemarchand <romlem@google.com>,
Colin Cross <ccross@google.com>, Todd Kjos <tkjos@google.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: Severe performance regression w/ 4.4+ on Android due to cgroup locking changes
Date: Thu, 14 Jul 2016 18:14:13 +0200 [thread overview]
Message-ID: <20160714161413.GD30154@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20160714145844.GA7760@redhat.com>
On Thu, Jul 14, 2016 at 04:58:44PM +0200, Oleg Nesterov wrote:
>
> Of course, this leads to another question: do we really need rcu-sync at
> all, or should we change percpu-rwsem to always work in the "slow" mode
> which is not that slow with your change... I'd like to keep it ;)
>
> What do you think?
Yes, I think we wants to keep it. There are users where the read size
cost really are performance critical. I still have to repost that lglock
removal series for example, which replaces the fs/locks lglock with a
percpu-rwsem.
next prev parent reply other threads:[~2016-07-14 16:14 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-13 0:00 Severe performance regression w/ 4.4+ on Android due to cgroup locking changes John Stultz
2016-07-13 8:21 ` Peter Zijlstra
2016-07-13 14:42 ` Paul E. McKenney
2016-07-13 18:13 ` Dmitry Shmidt
2016-07-13 18:32 ` Paul E. McKenney
2016-07-13 18:21 ` Tejun Heo
2016-07-13 18:33 ` Tejun Heo
2016-07-13 20:13 ` John Stultz
2016-07-13 20:18 ` Tejun Heo
2016-07-13 20:26 ` Peter Zijlstra
2016-07-13 20:39 ` Tejun Heo
2016-07-13 20:51 ` Peter Zijlstra
2016-07-13 21:01 ` Tejun Heo
2016-07-13 21:03 ` Paul E. McKenney
2016-07-13 21:05 ` Tejun Heo
2016-07-13 21:18 ` Paul E. McKenney
2016-07-13 21:42 ` Paul E. McKenney
2016-07-13 21:46 ` John Stultz
2016-07-13 22:17 ` Paul E. McKenney
2016-07-13 22:39 ` John Stultz
2016-07-13 23:02 ` Paul E. McKenney
2016-07-13 23:04 ` Paul E. McKenney
2016-07-14 11:35 ` Tejun Heo
2016-07-14 12:04 ` Peter Zijlstra
2016-07-14 12:08 ` Tejun Heo
2016-07-14 12:20 ` Peter Zijlstra
2016-07-14 15:07 ` Tejun Heo
2016-07-14 15:24 ` Tejun Heo
2016-07-14 16:32 ` Peter Zijlstra
2016-07-14 17:34 ` Oleg Nesterov
2016-07-14 16:54 ` John Stultz
2016-07-13 22:25 ` John Stultz
2016-07-13 22:01 ` Tejun Heo
2016-07-13 22:33 ` Paul E. McKenney
2016-07-14 6:49 ` Peter Zijlstra
2016-07-14 11:20 ` Tejun Heo
2016-07-14 12:11 ` Peter Zijlstra
2016-07-14 15:14 ` Tejun Heo
2016-07-14 13:18 ` Peter Zijlstra
2016-07-14 14:14 ` Peter Zijlstra
2016-07-14 14:58 ` Oleg Nesterov
2016-07-14 16:14 ` Peter Zijlstra [this message]
2016-07-14 16:37 ` Peter Zijlstra
2016-07-14 17:05 ` Oleg Nesterov
2016-07-14 16:23 ` Paul E. McKenney
2016-07-14 16:45 ` Peter Zijlstra
2016-07-14 17:15 ` Paul E. McKenney
2016-07-14 16:43 ` John Stultz
2016-07-14 16:49 ` Peter Zijlstra
2016-07-14 17:02 ` John Stultz
2016-07-14 17:13 ` Oleg Nesterov
2016-07-14 17:30 ` John Stultz
2016-07-14 17:41 ` Oleg Nesterov
2016-07-14 17:51 ` John Stultz
2016-07-14 18:09 ` Oleg Nesterov
2016-07-14 18:36 ` Peter Zijlstra
2016-07-14 19:35 ` Peter Zijlstra
2016-07-13 20:57 ` John Stultz
2016-07-13 20:52 ` Paul E. McKenney
2016-07-13 20:57 ` Peter Zijlstra
2016-07-13 21:08 ` Paul E. McKenney
2016-07-13 21:01 ` Dmitry Shmidt
2016-07-13 21:03 ` John Stultz
2016-07-13 21:05 ` Paul E. McKenney
2016-07-13 20:31 ` Dmitry Shmidt
2016-07-13 20:44 ` Colin Cross
2016-07-13 20:54 ` Tejun Heo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160714161413.GD30154@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=ccross@google.com \
--cc=dimitrysh@google.com \
--cc=john.stultz@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=oleg@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=romlem@google.com \
--cc=tj@kernel.org \
--cc=tkjos@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.