Date: Wed, 28 Apr 2010 16:15:45 +0800
From: Yong Zhang <yong.zhang@windriver.com>
To: Changli Gao <xiaosuo@gmail.com>
Cc: Xiaotian Feng <xtfeng@gmail.com>, Ingo Molnar <mingo@elte.hu>,
       Alexander Viro <viro@zeniv.linux.org.uk>,
       Andrew Morton <akpm@linux-foundation.org>,
       "Eric W. Biederman" <ebiederm@xmission.com>,
       Davide Libenzi <davidel@xmailserver.org>,
       Roland Dreier <rolandd@cisco.com>,
       Stefan Richter <stefanr@s5r6.in-berlin.de>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       "David S. Miller" <davem@davemloft.net>,
       Eric Dumazet <dada1@cosmosbay.com>, Christoph Lameter <cl@linux.com>,
       Andreas Herrmann <andreas.herrmann3@amd.com>,
       Thomas Gleixner <tglx@linutronix.de>,
       David Howells <dhowells@redhat.com>, Takashi Iwai <tiwai@suse.de>,
       linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC] sched: implement the exclusive wait queue as a LIFO queue
Message-ID: <20100428081545.GA19027@windriver.com>
Reply-To: Yong Zhang <yong.zhang@windriver.com>
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On Wed, Apr 28, 2010 at 03:52:01PM +0800, Changli Gao wrote:
> On Wed, Apr 28, 2010 at 3:47 PM, Xiaotian Feng <xtfeng@gmail.com> wrote:
> > On Wed, Apr 28, 2010 at 1:03 PM, Changli Gao <xiaosuo@gmail.com> wrote:
> >> implement the exclusive wait queue as a LIFO queue
> >>
> >> If the exclusive wait queue is also a LIFO queue as the normal wait queue, the
> >> process who goes to sleep recently, will be woke up first. As its memory is
> >> more likely in cache, we will get better performance. And when there are many
> >> processes waiting on a exclusive wait queue, some of them may not be woke up,
> >> if the others can handle the workload, and it will reduce the load of
> >> the scheduler.
> >>
> >
> > Starve some processes for performance?
> >
> 
> Starve? Oh, No. If we don't need these processes, and we can do better

What do you mean "we don't need these processes"?

> without them, why we wake them up?

So some processs(at the tail of exclusive list)will be treated abnormally
and it will sleep for a long time, is this reasonable?

> 
> 
> -- 
> Regards，
> Changli Gao(xiaosuo@gmail.com)
> --
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