From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 23 Feb 2007 09:49:52 +0000 (GMT) Received: from web7914.mail.in.yahoo.com ([202.86.4.90]:14739 "HELO web7914.mail.in.yahoo.com") by ftp.linux-mips.org with SMTP id S20037707AbXBWJtr (ORCPT ); Fri, 23 Feb 2007 09:49:47 +0000 Received: (qmail 89556 invoked by uid 60001); 23 Feb 2007 09:48:38 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.in; h=X-YMail-OSG:Received:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=n6RjLV+82WGXCwqqjudRDHRPudETAKusK09k1MRNnSfk0fK841s/nRjFzqQp6QzC9z0A2kcxw5FuyCcB+o4FP7nqZoFZBZP7ALOrpszPs7LM/chWKlcZyfxsg2jMd+7cGZ4GRnew/AH90CNxYFhai5UuEwAfH9zS2sBD3C9bm3U=; X-YMail-OSG: be7womkVM1ncZ5y.BN6Q9QCOh_GkYYTfKbq8S_YC.7jYJe9wMUWtFVwhANbtGGJqjOIFs7bRHeG2x1EXXjjsNAsFf6ljgr.wzOA__c7XntutQYdQRtAQZwq85RKVbwlG5uZdYz2J5tT8cIPUqzlsKQ-- Received: from [61.246.223.98] by web7914.mail.in.yahoo.com via HTTP; Fri, 23 Feb 2007 09:48:38 GMT Date: Fri, 23 Feb 2007 09:48:38 +0000 (GMT) From: sathesh babu Subject: Re: unaligned access To: Ralf Baechle , "Kevin D. Kissell" Cc: sathesh babu , Rajat Jain , linux-mips@linux-mips.org In-Reply-To: <20070223030645.GA1349@linux-mips.org> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1192634343-1172224118=:88566" Content-Transfer-Encoding: 8bit Message-ID: <623154.88566.qm@web7914.mail.in.yahoo.com> Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 14216 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: sathesh_edara2003@yahoo.co.in Precedence: bulk X-list: linux-mips --0-1192634343-1172224118=:88566 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit It would be good idea to know which process hitting unaligned access and PC. So that we can try to fix unaligned access when it causes the performance bottleneck. Could you please share details about logging the unaligned accesses using sysctl. Thanks in advance Regards, Sathesh Ralf Baechle wrote: On Thu, Feb 22, 2007 at 04:06:57PM +0100, Kevin D. Kissell wrote: > Default behavior in MIPS is to silently fix up and emulate. A MIPS-specific > system call (sys_sysmips with the command argument of MIPS_FIXADE > and a parameter agument of zero) allows for this to be overridden, so that > such accesses will be fatal. It looks as if there was once support to log the events > to syslog, independently of whether or not they were fixed up, but it doesn't look to me > as if that still works in 2.6.x kernels. There used to be a configuration option to allow logging which was a leftover from the times when I implemented the unaligned emulation. I did never find it useful later on, so I removed that in almost 9 years ago and nobody missed it since :-) But I don't mind putting it back, controllable by sysctl if there is any demand for it. Ralf --------------------------------- Here’s a new way to find what you're looking for - Yahoo! Answers --0-1192634343-1172224118=:88566 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit
It would be good idea to know which process hitting unaligned access and PC.
So that we can try to fix unaligned access when it causes the  performance bottleneck.
 
Could you please share details about logging the unaligned accesses using sysctl.
 
Thanks in advance
 
Regards,
Sathesh

Ralf Baechle <ralf@linux-mips.org> wrote:
On Thu, Feb 22, 2007 at 04:06:57PM +0100, Kevin D. Kissell wrote:

> Default behavior in MIPS is to silently fix up and emulate. A MIPS-specific
> system call (sys_sysmips with the command argument of MIPS_FIXADE
> and a parameter agument of zero) allows for this to be overridden, so that
> such accesses will be fatal. It looks as if there was once support to log the events
> to syslog, independently of whether or not they were fixed up, but it doesn't look to me
> as if that still works in 2.6.x kernels.

There used to be a configuration option to allow logging which was a
leftover from the times when I implemented the unaligned emulation. I
did never find it useful later on, so I removed that in almost 9 years
ago and nobody missed it since :-)

But I don't mind putting it back, controllable by sysctl if there is any
demand for it.

Ralf


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