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
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