From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Hillf Danton" <hdanton@sina.com>, 马振华 <mazhenhua@xiaomi.com>,
mingo <mingo@redhat.com>, will <will@kernel.org>,
"boqun.feng" <boqun.feng@gmail.com>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [BUG]locking/rwsem: only clean RWSEM_FLAG_HANDOFF when already set
Date: Thu, 11 Nov 2021 16:46:31 -0500 [thread overview]
Message-ID: <88037962-a31b-913e-7903-68fac7e3329d@redhat.com> (raw)
In-Reply-To: <YY2NRpg1q6hLIqpK@hirez.programming.kicks-ass.net>
On 11/11/21 16:38, Peter Zijlstra wrote:
> On Thu, Nov 11, 2021 at 04:01:16PM -0500, Waiman Long wrote:
>
>>>> + if (has_handoff || (!waiter->rt_task &&
>>>> + !time_after(jiffies, waiter->timeout)))
>>> Does ->rt_task really help over rt_task(current) ? I suppose there's an
>>> argument for locality, but that should be pretty much it, no?
>> Waiting for the timeout may introduce too much latency for RT task. That is
>> the only reason I am doing it. I can take it out if you think it is not
>> necessary.
> I meant simply calling rt_task(waiter->task) here, instead of mucking about
> with the extra variable.
OK, that make sense.
Cheers,
Longman
next prev parent reply other threads:[~2021-11-11 21:46 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4fafad133b074f279dbab1aa3642e23f@xiaomi.com>
2021-11-07 3:25 ` Waiman Long
2021-11-07 3:28 ` Waiman Long
[not found] ` <20211107090131.1535-1-hdanton@sina.com>
2021-11-07 15:24 ` Waiman Long
2021-11-07 19:52 ` Waiman Long
2021-11-10 21:38 ` Peter Zijlstra
2021-11-11 2:42 ` Maria Yu
2021-11-11 15:08 ` Peter Zijlstra
2021-11-11 19:14 ` Waiman Long
2021-11-11 19:20 ` Peter Zijlstra
2021-11-11 19:36 ` Waiman Long
2021-11-11 19:52 ` Waiman Long
2021-11-11 20:26 ` Peter Zijlstra
2021-11-11 21:01 ` Waiman Long
2021-11-11 21:25 ` Waiman Long
2021-11-11 21:53 ` Peter Zijlstra
2021-11-11 21:55 ` Waiman Long
2021-11-11 22:00 ` Waiman Long
2021-11-11 21:38 ` Peter Zijlstra
2021-11-11 21:46 ` Waiman Long [this message]
2021-11-11 20:35 ` Peter Zijlstra
2021-11-11 20:39 ` Peter Zijlstra
2021-11-11 20:45 ` Waiman Long
2021-11-11 21:27 ` Peter Zijlstra
2021-11-11 21:54 ` Waiman Long
2021-11-11 20:50 ` Peter Zijlstra
2021-11-11 21:09 ` Waiman Long
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