From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
bigeasy@linutronix.de,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
daniel.wagner@siemens.com, Will Deacon <will.deacon@arm.com>,
x86@kernel.org, Linus Torvalds <torvalds@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>,
boqun.feng@gmail.com, Paul McKenney <paulmck@linux.vnet.ibm.com>
Subject: Re: [Problem] Cache line starvation
Date: Wed, 3 Oct 2018 10:28:42 +0200 [thread overview]
Message-ID: <20181003082842.GN26858@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <alpine.DEB.2.21.1810031005210.1435@nanos.tec.linutronix.de>
On Wed, Oct 03, 2018 at 10:07:05AM +0200, Thomas Gleixner wrote:
> On Wed, 3 Oct 2018, Catalin Marinas wrote:
>
> > On Fri, 21 Sep 2018 at 13:22, Peter Zijlstra <peterz@infradead.org> wrote:
> > > On Fri, Sep 21, 2018 at 02:02:26PM +0200, Sebastian Andrzej Siewior wrote:
> > > > We reproducibly observe cache line starvation on a Core2Duo E6850 (2
> > > > cores), a i5-6400 SKL (4 cores) and on a NXP LS2044A ARM Cortex-A72 (4
> > > > cores).
> Except that the ARM64 ticket locks are not preventing the starvation
> issue. Neither do the qrlocks on ARM64 on later kernels.
That A72 is ARMv8-A afaict, that doesn't have the fancy LSE bits (which
are new in ARMv8.1) on and thus ends up using LL/SC. And LL/SC has
similar issues as cmpxchg loops.
AFAICT Cortex-A75 is the first that has LSE on (that's an ARMv8.2-A).
next prev parent reply other threads:[~2018-10-03 8:28 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-21 12:02 [Problem] Cache line starvation Sebastian Andrzej Siewior
2018-09-21 12:13 ` Thomas Gleixner
2018-09-21 12:50 ` Sebastian Andrzej Siewior
2018-09-21 12:20 ` Peter Zijlstra
2018-09-21 12:54 ` Thomas Gleixner
2018-10-03 7:51 ` Catalin Marinas
2018-10-03 8:07 ` Thomas Gleixner
2018-10-03 8:28 ` Peter Zijlstra [this message]
2018-10-03 10:43 ` Thomas Gleixner
2018-10-03 8:23 ` Peter Zijlstra
2018-09-26 7:34 ` Peter Zijlstra
2018-09-26 8:04 ` Thomas Gleixner
2018-09-26 12:53 ` Will Deacon
2018-09-27 14:25 ` Kurt Kanzenbach
2018-09-27 14:41 ` Kurt Kanzenbach
2018-09-27 14:47 ` Thomas Gleixner
2018-09-28 9:05 ` Kurt Kanzenbach
2018-09-28 15:26 ` Kurt Kanzenbach
2018-09-28 19:26 ` Sebastian Andrzej Siewior
2018-09-28 19:34 ` Thomas Gleixner
2018-10-02 6:31 ` Daniel Wagner
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=20181003082842.GN26858@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=bigeasy@linutronix.de \
--cc=boqun.feng@gmail.com \
--cc=catalin.marinas@arm.com \
--cc=daniel.wagner@siemens.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=will.deacon@arm.com \
--cc=x86@kernel.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;
as well as URLs for NNTP newsgroup(s).