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From: Hubertus Franke <frankeh@watson.ibm.com>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: linux-kernel@vger.kernel.org, lse-tech@lists.sourceforge.net
Subject: Re: Fwd: [Lse-tech] get_pid() performance fix
Date: Tue, 5 Mar 2002 11:43:44 -0500	[thread overview]
Message-ID: <20020305164239.8EFFF3FE06@smtp.linux.ibm.com> (raw)
In-Reply-To: <20020305145004.BFA503FE06@smtp.linux.ibm.com> <87bse39e1f.fsf@devron.myhome.or.jp>
In-Reply-To: <87bse39e1f.fsf@devron.myhome.or.jp>

On Tuesday 05 March 2002 11:26 am, OGAWA Hirofumi wrote:
> Hubertus Franke <frankeh@watson.ibm.com> writes:
> > @@ -153,13 +155,18 @@
> >                               if(last_pid & 0xffff8000)
> >                                     last_pid = 300;
> >                               next_safe = PID_MAX;
> > +                             goto repeat;
> >                         }
> > -                       goto repeat;
> > +                       if(unlikely(last_pid == beginpid))
> > +                             goto nomorepids;
> > +                       continue;
>
> It isn't guaranteed that pid is unique.
>
> In the case:
> 	task->pid = 300, task->xxx = 301
> 	pid 301 is free
>
> 	This get_pid() returns 301.
>
> Regards.

No the point of this patch was to limit the search time for finding
the next available pid. We are not mocking around with the 
logic that declares a pid available or not. That stays the same.
However, one doesn't need to start every single time from the
beginning to find the next available pid.

-- 
-- Hubertus Franke  (frankeh@watson.ibm.com)

  reply	other threads:[~2002-03-05 16:43 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-03-05  1:57 Fwd: [Lse-tech] get_pid() performance fix Hubertus Franke
2002-03-05 16:26 ` OGAWA Hirofumi
2002-03-05 16:43   ` Hubertus Franke [this message]
2002-03-07  3:56 ` Rusty Russell
2002-03-07 14:35   ` Hubertus Franke
2002-03-07 14:54     ` Guest section DW
2002-03-07 19:07       ` Hubertus Franke
2002-03-07 19:44         ` Richard B. Johnson
2002-03-07 19:46         ` Guest section DW
2002-03-07 23:14           ` Hubertus Franke
2002-03-07 15:21   ` Dave McCracken
2002-03-05 16:43 Rajan Ravindran
2002-03-05 17:57 ` OGAWA Hirofumi
2002-03-05 19:53   ` Hubertus Franke
2002-03-05 20:10     ` OGAWA Hirofumi
2002-03-05 21:59       ` Hubertus Franke
2002-03-05 22:48         ` OGAWA Hirofumi
2002-03-05 23:40           ` Hubertus Franke
2002-03-07 22:37 Manfred Spraul

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