From: Yuyang Du <yuyang.du@intel.com>
To: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org,
Byungchul Park <byungchul.park@lge.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Luca Abeni <luca.abeni@unitn.it>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Rik van Riel <riel@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Wanpeng Li <wanpeng.li@hotmail.com>,
Mel Gorman <mgorman@techsingularity.net>,
Mike Galbraith <umgwanakikbuti@gmail.com>
Subject: Re: [RFC][PATCH 5/5] sched/core: Add debug code to catch missing update_rq_clock()
Date: Wed, 18 May 2016 03:01:27 +0800 [thread overview]
Message-ID: <20160517190127.GE8790@intel.com> (raw)
In-Reply-To: <20160517122415.GD21993@codeblueprint.co.uk>
On Tue, May 17, 2016 at 01:24:15PM +0100, Matt Fleming wrote:
> So, if the code looks like the following, either now or in the future,
>
> static void __schedule(bool preempt)
> {
> ...
> /* Clear RQCF_ACT_SKIP */
> rq->clock_update_flags = 0;
> ...
> delta = rq_clock();
> }
Sigh, you even said "Clear RQCF_ACT_SKIP", but you not only clear it,
you clear everything. And if you clear the RQCF_UPDATE also (maybe you
shouldn't, but actually it does not matter), of course you will get
a warning...
In addition, it looks like multiple skips are possible, so:
update_rq_clock() {
rq->clock_update_flags |= RQCF_UPDATE;
...
}
instead of clearing the skip flag there.
next prev parent reply other threads:[~2016-05-18 2:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-12 19:49 [RFC][PATCH 0/5] sched: Diagnostic checks for missing rq clock updates Matt Fleming
2016-05-12 19:49 ` [RFC][PATCH 1/5] sched/fair: Update the rq clock before detaching tasks Matt Fleming
2016-05-12 19:49 ` [RFC][PATCH 2/5] sched: Add wrappers for lockdep_(un)pin_lock() Matt Fleming
2016-05-12 19:49 ` [RFC][PATCH 3/5] sched/core: Reset RQCF_ACT_SKIP before unpinning rq->lock Matt Fleming
2016-05-12 19:49 ` [RFC][PATCH 4/5] sched/fair: Push rq lock pin/unpin into idle_balance() Matt Fleming
2016-05-12 19:49 ` [RFC][PATCH 5/5] sched/core: Add debug code to catch missing update_rq_clock() Matt Fleming
2016-05-15 2:14 ` Yuyang Du
2016-05-16 9:46 ` Matt Fleming
2016-05-16 20:11 ` Yuyang Du
2016-05-17 12:24 ` Matt Fleming
2016-05-17 19:01 ` Yuyang Du [this message]
2016-05-18 8:41 ` Matt Fleming
2016-05-18 22:51 ` Yuyang Du
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=20160517190127.GE8790@intel.com \
--to=yuyang.du@intel.com \
--cc=byungchul.park@lge.com \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luca.abeni@unitn.it \
--cc=matt@codeblueprint.co.uk \
--cc=mgorman@techsingularity.net \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rafael.j.wysocki@intel.com \
--cc=riel@redhat.com \
--cc=tglx@linutronix.de \
--cc=umgwanakikbuti@gmail.com \
--cc=wanpeng.li@hotmail.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.