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To: frankeh@watson.ibm.com
Cc: linux-kernel@vger.kernel.org, lse-tech@lists.sourceforge.net
Subject: Re: Fwd: [Lse-tech] get_pid() performance fix
In-Reply-To: <20020305145004.BFA503FE06@smtp.linux.ibm.com>
From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Date: Wed, 06 Mar 2002 01:26:20 +0900
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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.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
-
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