From: Davidlohr Bueso <dave@stgolabs.net>
To: Waiman Long <waiman.long@hpe.com>
Cc: Jason Low <jason.low2@hpe.com>,
imre.deak@intel.com, Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Chris Wilson <chris@chris-wilson.co.uk>,
Daniel Vetter <daniel.vetter@intel.com>
Subject: Re: [RFC] Avoid mutex starvation when optimistic spinning is disabled
Date: Fri, 22 Jul 2016 11:03:09 -0700 [thread overview]
Message-ID: <20160722180309.GB1881@linux-80c1.suse> (raw)
In-Reply-To: <57925E25.8010506@hpe.com>
On Fri, 22 Jul 2016, Waiman Long wrote:
>I think making mutex_trylock() fail maybe a bit too far. Do we really
>have any real workload that cause starvation problem because of that.
>Code that does mutex_trylock() in a loop can certainly cause lock
>starvation, but it is not how mutex_trylock() is supposed to be used.
>We can't build in safeguard for all the possible abuses of the mutex
>APIs.
True, and that's actually why I think that 'fixing' the !SPIN_ON_OWNER case
is a bit too far in the first place: most of the archs that will care about
this already have ARCH_SUPPORTS_ATOMIC_RMW. The extra code for dealing with
this is not worth it imo.
Thanks,
Davidlohr
next prev parent reply other threads:[~2016-07-22 18:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-18 16:16 [RFC] locking/mutex: Fix starvation of sleeping waiters Imre Deak
2016-07-18 17:15 ` Peter Zijlstra
2016-07-18 17:47 ` Jason Low
2016-07-19 16:53 ` Imre Deak
2016-07-19 22:57 ` Jason Low
2016-07-19 23:04 ` [RFC] Avoid mutex starvation when optimistic spinning is disabled Jason Low
2016-07-20 4:39 ` Jason Low
2016-07-20 13:29 ` Imre Deak
2016-07-21 20:57 ` Jason Low
2016-07-22 17:55 ` Waiman Long
2016-07-22 18:03 ` Davidlohr Bueso [this message]
2016-07-22 18:29 ` Imre Deak
2016-07-22 19:26 ` Davidlohr Bueso
2016-07-22 19:53 ` Imre Deak
2016-07-20 18:37 ` Waiman Long
2016-07-21 22:29 ` Jason Low
2016-07-22 9:34 ` Imre Deak
2016-07-22 18:44 ` Jason Low
2016-07-22 18:01 ` Waiman Long
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=20160722180309.GB1881@linux-80c1.suse \
--to=dave@stgolabs.net \
--cc=chris@chris-wilson.co.uk \
--cc=daniel.vetter@intel.com \
--cc=imre.deak@intel.com \
--cc=jason.low2@hpe.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=waiman.long@hpe.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.