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From: george anzinger <george@mvista.com>
To: Parity Error <bootup@mail.ru>
Cc: linux-kernel@vger.kernel.org
Subject: Re: current->need_reshed, can it be a global flag ?
Date: Thu, 22 Mar 2001 10:45:07 -0800	[thread overview]
Message-ID: <3ABA4833.C169783@mvista.com> (raw)
In-Reply-To: <E14g4XZ-0009hb-00@f5.mail.ru>

Parity Error wrote:
> 
> instead of need_reshed being a per-task flag, could it be
> as a global flag ?, since every time current->need_reshed
> is checked, schedule() is just called to pick another
> process.
> 
> ---
But for which cpu?  Really this is a short cut to provide a per cpu area
that I think works very well, thank you.

Putting it in a real cpu data area would make access slower.  The
"current" pointer is either very quickly computed or pre loaded in a
register (depends on the platform) so it is about as fast as it can get
as it is.

Also, the flag is often checked by selective preemption code in the
kernel.  Even more often by the full preemption patch.

Nuf said
George

      reply	other threads:[~2001-03-22 18:49 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-03-22 12:50 current->need_reshed, can it be a global flag ? Parity Error
2001-03-22 18:45 ` george anzinger [this message]

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