From: Hillf Danton <hdanton@sina.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Mel Gorman <mgorman@techsingularity.net>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Davidlohr Bueso <dave@stgolabs.net>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] locking/rwbase: Prevent indefinite writer starvation
Date: Fri, 20 Jan 2023 17:37:11 +0800 [thread overview]
Message-ID: <20230120093711.3862-1-hdanton@sina.com> (raw)
In-Reply-To: <Y8lxhkxNJuPHu3xG@linutronix.de>
On Thu, 19 Jan 2023 17:36:22 +0100 Sebastian Andrzej Siewior
> On 2023-01-19 21:59:03 [+0800], Hillf Danton wrote:
> > On Thu, 19 Jan 2023 09:32:22 +0100 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> > >
> > > As far as Mel's efforts go, I am satisfied so far.
> >
> > If not because you can, could you specify why 4ms fails to cure starvation?
>
> It does not fail to cure the starvation. I haven't tested it myself but
> base on Mel's description and the patch it very much looks like it cures
> the writer starvation.
>
> If you don't like the 4ms, it could be 1ms or 40ms - it does not really
> matter. The 4ms is aligned on the generic implementation which uses the
> same value. Unless there is strong evidence to use something else I
> don't see the need to diverse.
I am fine with either 4ms or 40ms, or a second.
Given the cure, does it still work when reader bias for RT tasks is allowed?
If not, why keep starving waiters after they pay the 40ms price?
next prev parent reply other threads:[~2023-01-20 9:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20230117083817.togfwc5cy4g67e5r@techsingularity.net>
[not found] ` <Y8avJm1FQI9vB9cv@linutronix.de>
[not found] ` <20230117165021.t5m7c2d6frbbfzig@techsingularity.net>
[not found] ` <Y8gPhTGkfCbGwoUu@linutronix.de>
[not found] ` <20230118173130.4n2b3cs4pxiqnqd3@techsingularity.net>
2023-01-19 1:15 ` Hillf Danton
2023-01-19 8:32 ` Sebastian Andrzej Siewior
2023-01-19 13:59 ` Hillf Danton
2023-01-19 16:36 ` Sebastian Andrzej Siewior
2023-01-20 9:37 ` Hillf Danton [this message]
2023-01-20 18:34 ` Sebastian Andrzej Siewior
2023-01-21 3:46 ` Hillf Danton
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