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To: "Albert Cahalan" <acahalan@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: wait4/waitpid/waitid oddness
References: <787b0d920604052038i3a75bdb6ic0818d93805b881b@mail.gmail.com>
From: ebiederm@xmission.com (Eric W. Biederman)
Date: Fri, 07 Apr 2006 12:23:38 -0600
In-Reply-To: <787b0d920604052038i3a75bdb6ic0818d93805b881b@mail.gmail.com> (Albert
 Cahalan's message of "Wed, 5 Apr 2006 23:38:20 -0400")
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"Albert Cahalan" <acahalan@gmail.com> writes:

> The kernel prohibits:
>
> 1. WNOHANG on waitpid/wait4

Not 2.6.17-rc1, and not for a lot of earlier kernels.
At least not on ingress, and just skimming the code
I can't see any deeper checks that would prevent this.

> 2. __WALL on waitid
>
> Why? I need both at once.

Which kernel is failing, and how?

Eric