From: Andrew Morton <akpm@linux-foundation.org>
To: Jason Low <jason.low2@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Oleg Nesterov <oleg@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org,
Frederic Weisbecker <fweisbec@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Steven Rostedt <rostedt@goodmis.org>,
Terry Rudd <terry.rudd@hp.com>, Rik van Riel <riel@redhat.com>,
Scott J Norton <scott.norton@hp.com>
Subject: Re: [PATCH 0/3] timer: Improve itimers scalability
Date: Tue, 25 Aug 2015 20:27:10 -0700 [thread overview]
Message-ID: <20150825202710.d960a928.akpm@linux-foundation.org> (raw)
In-Reply-To: <1440559068-29680-1-git-send-email-jason.low2@hp.com>
On Tue, 25 Aug 2015 20:17:45 -0700 Jason Low <jason.low2@hp.com> wrote:
> When running a database workload on a 16 socket machine, there were
> scalability issues related to itimers.
>
> Commit 1018016c706f addressed the issue with the thread_group_cputimer
> spinlock taking up a significant portion of total run time.
>
> This patch series address the other issue where a lot of time is spent
> trying to acquire the sighand lock. It was found in some cases that
> 200+ threads were simultaneously contending for the same sighand lock,
> reducing throughput by more than 30%.
Does this imply that the patchset increased the throughput of this
workload by 30%?
And is this test case realistic? If not, what are the benefits on a
real-world workload?
next prev parent reply other threads:[~2015-08-26 3:27 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-26 3:17 [PATCH 0/3] timer: Improve itimers scalability Jason Low
2015-08-26 3:17 ` [PATCH 1/3] timer: Optimize fastpath_timer_check() Jason Low
2015-08-26 21:57 ` Frederic Weisbecker
2015-08-31 15:15 ` Davidlohr Bueso
2015-08-31 19:40 ` Jason Low
2015-08-26 3:17 ` [PATCH 2/3] timer: Check thread timers only when there are active thread timers Jason Low
2015-08-26 3:17 ` [PATCH 3/3] timer: Reduce unnecessary sighand lock contention Jason Low
2015-08-26 17:53 ` Linus Torvalds
2015-08-26 22:31 ` Frederic Weisbecker
2015-08-26 22:57 ` Jason Low
2015-08-26 22:56 ` Frederic Weisbecker
2015-08-26 23:32 ` Jason Low
2015-08-27 4:52 ` Jason Low
2015-08-27 12:53 ` Frederic Weisbecker
2015-08-27 20:29 ` Jason Low
2015-08-27 21:12 ` Frederic Weisbecker
2015-08-26 3:27 ` Andrew Morton [this message]
2015-08-26 16:33 ` [PATCH 0/3] timer: Improve itimers scalability Jason Low
2015-08-26 17:08 ` Oleg Nesterov
2015-08-26 22:07 ` Jason Low
2015-08-26 22:53 ` Hideaki Kimura
2015-08-26 23:13 ` Frederic Weisbecker
2015-08-26 23:45 ` Hideaki Kimura
2015-08-27 13:18 ` Frederic Weisbecker
2015-08-27 14:47 ` Steven Rostedt
2015-08-27 15:09 ` Thomas Gleixner
2015-08-27 15:17 ` Frederic Weisbecker
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=20150825202710.d960a928.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=dave@stgolabs.net \
--cc=fweisbec@gmail.com \
--cc=jason.low2@hp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=rostedt@goodmis.org \
--cc=scott.norton@hp.com \
--cc=terry.rudd@hp.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox