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From: Steve Ellcey <sellcey@mips.com>
To: Carlos O'Donell <carlos@systemhalted.org>
Cc: Andrew Pinski <pinskia@gmail.com>,
	"Joseph S. Myers"	<joseph@codesourcery.com>,
	Carlos O'Donell <carlos@redhat.com>,
	"libc-ports@sourceware.org" <libc-ports@sourceware.org>
Subject: Re: [patch, mips] Improved memset for MIPS
Date: Fri, 13 Dec 2013 00:14:00 -0000	[thread overview]
Message-ID: <1386893669.2764.30.camel@ubuntu-sellcey> (raw)
In-Reply-To: <CAE2sS1iqz-GVB8hZVbZL7D4hr6Xs09ofPtaU2WQ6wzeBAjcf8w@mail.gmail.com>

On Thu, 2013-12-12 at 19:01 -0500, Carlos O'Donell wrote:

> > I noticed this patch causes some performance regressions on Octeon due
> > to having 128 byte cache lines.
> > Changing PREFETCH_CHUNK/PREFETCH_FOR_STORE to assume 128 byte cache
> > line gives us the performance back and improves over the original code
> > at least 15%.
> > That is:
> > #  define PREFETCH_CHUNK 128
> > #  define PREFETCH_FOR_STORE(chunk, reg) \
> >     pref PREFETCH_STORE_HINT, (chunk)*128(reg);
> 
> Submit a patch for that?
> 
> We have microbenchmarks now, but the next hardest
> part is going to be archiving data by device so that
> the community can help track performance and point
> out regressions like this.
> 
> Cheers,
> Carlos.

Unless the change is under some kind of ifdef for Octeon changing this
will probably slow down other MIPS chips.  Most of them have 32 byte
cache lines.

Steve Ellcey
sellcey@mips.com


  reply	other threads:[~2013-12-13  0:14 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-05 17:06 Steve Ellcey 
2013-09-06  0:40 ` Mike Frysinger
2013-09-06 15:42   ` Steve Ellcey
2013-09-06  4:18 ` Carlos O'Donell
2013-09-06 16:03   ` Steve Ellcey
2013-09-06 17:12     ` Carlos O'Donell
2013-09-06 23:33       ` Steve Ellcey
2013-09-07  2:38         ` Carlos O'Donell
2013-09-10 20:31           ` Steve Ellcey
2013-09-10 21:01             ` Carlos O'Donell
2013-09-10 21:14               ` Steve Ellcey
2013-09-10 22:35                 ` Carlos O'Donell
2013-09-10 22:38                   ` Carlos O'Donell
2013-09-07  5:46         ` Andreas Schwab
2013-09-06 14:31 ` Joseph S. Myers
2013-09-06 15:58   ` Steve Ellcey
2013-09-06 16:09     ` Joseph S. Myers
2013-09-06 16:50       ` Steve Ellcey
2013-09-06 16:59         ` Joseph S. Myers
2013-09-06 17:43           ` Steve Ellcey
2013-09-06 18:57             ` Brooks Moses
2013-09-18 17:41           ` Steve Ellcey
2013-09-19 15:25             ` Carlos O'Donell
2013-09-19 17:02               ` Steve Ellcey
2013-09-20 16:43             ` Joseph S. Myers
2013-09-20 17:32               ` Steve Ellcey
2013-12-12 22:19                 ` Andrew Pinski
2013-12-13  0:01                   ` Carlos O'Donell
2013-12-13  0:14                     ` Steve Ellcey [this message]
2013-12-13  0:22                       ` Andrew Pinski
2013-12-13  4:40                       ` Carlos O'Donell
2013-09-06 16:59       ` Steve Ellcey

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