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From: Neil Brown <neilb@suse.de>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Thu, 9 Apr 2009 16:05:55 +1000
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Cc: Greg Kroah-Hartman <gregkh@suse.de>, LKML <linux-kernel@vger.kernel.org>,
       Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [PATCH] sysfs poll should keep the poll rule of normal regular file.
In-Reply-To: message from KOSAKI Motohiro on Thursday April 9
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On Thursday April 9, kosaki.motohiro@jp.fujitsu.com wrote:
> > On Wednesday April 8, kosaki.motohiro@jp.fujitsu.com wrote:
> > > Because Ruby (the scripting language) VM assume select system-call against regular file don't block.
> > > (POSIX gurantee it.)
> > > But sysfs_poll() don't keep this rule although sysfs file can read and write always.
> > 
> > It would be nice to include a reference to where POSIX (or SUS)
> > guarantees it - though I suspect you are right.
> 
> Oh, very good opinion.
> 
> following explanation is better?
> 
> poll is requireed "Regular files shall always poll TRUE for reading and
> writing." by SUSv3.
>   see http://www.opengroup.org/onlinepubs/009695399/functions/poll.html
> 

Yes, that's excellent, thanks.

NeilBrown