From: Steven Rostedt <rostedt@goodmis.org>
To: Qais Yousef <qais.yousef@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Yury Norov <yury.norov@gmail.com>, Paul Turner <pjt@google.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Josh Don <joshdon@google.com>,
Pavan Kondeti <pkondeti@codeaurora.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/4] cpumask: Convert cpumask_any_but() to the new random function
Date: Tue, 14 Apr 2020 12:28:10 -0400 [thread overview]
Message-ID: <20200414122810.4b83ddd2@gandalf.local.home> (raw)
In-Reply-To: <20200414150556.10920-4-qais.yousef@arm.com>
On Tue, 14 Apr 2020 16:05:55 +0100
Qais Yousef <qais.yousef@arm.com> wrote:
> +int cpumask_any_but(const struct cpumask *srcp, unsigned int cpu)
> +{
> + unsigned int i;
> +
> + cpumask_check(cpu);
> +
> + for_each_cpu(i, srcp) {
> + i = cpumask_any(srcp);
Hmm, if the current CPU is the last CPU in the mask, and cpumask_any()
happens to return it, what happens?
> + if (i != cpu)
> + return i;
We loop again, and wouldn't i being the last CPU in the mask cause this
loop to exit, and return nr_cpu_ids?
-- Steve
> + }
> +
> + return nr_cpu_ids;
> +}
next prev parent reply other threads:[~2020-04-14 16:28 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 15:05 [PATCH 0/4] sched/rt: Distribute tasks in find_lowest_rq() Qais Yousef
2020-04-14 15:05 ` [PATCH 1/4] cpumask: Rename cpumask_any_and_distribute Qais Yousef
2020-04-14 15:05 ` [PATCH 2/4] cpumask: Make cpumask_any() truly random Qais Yousef
2020-04-14 16:19 ` Steven Rostedt
2020-04-15 9:36 ` Peter Zijlstra
2020-04-20 15:43 ` Qais Yousef
2020-04-20 21:36 ` Josh Don
2020-05-28 8:52 ` [cpumask] a7934287d8: BUG:using__this_cpu_read()in_preemptible[#]code:kworker kernel test robot
2020-04-14 15:05 ` [PATCH 3/4] cpumask: Convert cpumask_any_but() to the new random function Qais Yousef
2020-04-14 16:28 ` Steven Rostedt [this message]
2020-04-20 15:49 ` Qais Yousef
2020-04-14 15:05 ` [PATCH 4/4] sched/rt: Better distribute tasks that wakeup simultaneously Qais Yousef
2020-04-14 18:58 ` [PATCH 0/4] sched/rt: Distribute tasks in find_lowest_rq() Valentin Schneider
2020-04-14 20:27 ` Steven Rostedt
2020-04-14 20:56 ` Valentin Schneider
2020-04-15 9:39 ` Peter Zijlstra
2020-04-15 13:18 ` Steven Rostedt
2020-04-21 12:15 ` Qais Yousef
2020-04-21 12:13 ` Qais Yousef
2020-04-21 13:18 ` Valentin Schneider
2020-04-21 13:28 ` Vincent Guittot
2020-04-21 14:22 ` Yury Norov
2020-04-21 14:25 ` Qais Yousef
2020-04-21 14:09 ` Marc Zyngier
2020-04-21 14:22 ` Qais Yousef
2020-04-21 14:28 ` Marc Zyngier
2020-04-21 14:39 ` Qais Yousef
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