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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [PATCH 1/4] linux-user: add pselect syscall
Date: Fri, 26 Mar 2010 23:05:31 +0000
References: <cover.1269616764.git.riku.voipio@nokia.com>
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To: qemu-devel@nongnu.org
Cc: Riku Voipio <riku.voipio@nokia.com>, Riku Voipio <riku.voipio@iki.fi>, Michael Casadevall <mcasadevall@ubuntu.com>

>This patch adds support for the pselect syscall in linux-user emulation
>and also adds several support functions required to translate the
>timespec structs between the target and the host.

IIUC the whole point of the pselect is that it should be atomic. By emulating 
this in a non-atomic fasion I think you're re-introducing the race condition 
that it is designed to avoid.

Wouldn't it be better to just return ENOSYS and let the guest deal with the 
problem?

Paul