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From: Oleg Nesterov <oleg@redhat.com>
To: Ratan Nalumasu <rnalumasu@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@elte.hu>, Roland McGrath <roland@redhat.com>,
	Vitaly Mayatskikh <vmayatsk@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC,PATCH 0/2] do_wait() wakeup optimization
Date: Tue, 23 Jun 2009 16:30:54 +0200	[thread overview]
Message-ID: <20090623143054.GA10069@redhat.com> (raw)
In-Reply-To: <93ad5f3f0906230955x357ff9evc334d4a5c6def20@mail.gmail.com>

On 06/23, Ratan Nalumasu wrote:
>
> Yes, it is something we really need. The specific case I have (hundreds of
> NTPL threads in a program, and each thread managing a child process), the
> CPU load is >99% with NTPL threads, near 0% with the patch
                                                   ^^^^^^^^^

Thanks. Did you test this patch, or do you mean the previous one?

> So, yes, the complication is worthwhile.

I am asking because I am not sure this change is enough, note the
"We can make child_wait_callback() more clever later" in the changelog.

__wake_up_parent() passes key = p, but we can pass more info and do
additional checks in child_wait_callback().

Oleg.


  parent reply	other threads:[~2009-06-23 17:46 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-22 17:04 [RFC,PATCH 0/2] do_wait() wakeup optimization Oleg Nesterov
     [not found] ` <93ad5f3f0906230955x357ff9evc334d4a5c6def20@mail.gmail.com>
2009-06-23 14:30   ` Oleg Nesterov [this message]
     [not found]     ` <93ad5f3f0906240953v3b328f9bxca51cd9d3838d05c@mail.gmail.com>
2009-06-24 15:41       ` Oleg Nesterov

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