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From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <longman@redhat.com>
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 22:38:14 +0100	[thread overview]
Message-ID: <YY2NRpg1q6hLIqpK@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <be3dc705-494a-913e-230f-9533c7404ac2@redhat.com>

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.

  parent reply	other threads:[~2021-11-11 21:38 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 [this message]
2021-11-11 21:46                       ` Waiman Long
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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