From: Eugene Surovegin <ebs@ebshome.net>
To: Darin.Johnson@nokia.com
Cc: <linuxppc-embedded@lists.linuxppc.org>
Subject: RE: [RFC] consistent_sync and non L1 cache line aligned buffers
Date: Tue, 15 Jul 2003 13:39:19 -0700 [thread overview]
Message-ID: <5.1.0.14.2.20030715133146.030d2e60@mail.ebshome.net> (raw)
In-Reply-To: <F0B628F30F48064289D8CCC1EE21B7A80C48A5@mvebe001.americas.n okia.com>
At 01:18 PM 7/15/2003, Darin.Johnson@nokia.com wrote:
>I solved the problem (in a non-Linux system) by just flushing the first
>and last lines in the requested range, and invalidating the rest. The
>very slight performance hit is probably less than testing to see if the
>buffer is unaligned.
I don't think so.
If you take a look at the assembler output of my patch you'll see that test
for unaligned just accesses register, when dcbf may require memory access
which is *significantly* slower.
In majority of cases consistent_sync is called with properly aligned buffer
and I don't want to penalize this path by *unconditionally* (as you are
suggesting) flushing start and end of the buffer.
Eugene.
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next parent reply other threads:[~2003-07-15 20:39 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <F0B628F30F48064289D8CCC1EE21B7A80C48A5@mvebe001.americas.n okia.com>
2003-07-15 20:39 ` Eugene Surovegin [this message]
2003-07-15 21:26 ` [RFC] consistent_sync and non L1 cache line aligned buffers David Blythe
2003-07-15 22:15 ` Dan Malek
2003-07-16 0:12 Darin.Johnson
-- strict thread matches above, loose matches on Subject: below --
2003-07-15 23:04 Darin.Johnson
2003-07-15 23:34 ` Paul Mackerras
2003-07-15 23:50 ` Eugene Surovegin
2003-07-15 23:45 ` Matt Porter
2003-07-16 14:01 ` Dan Malek
2003-07-15 20:47 Darin.Johnson
2003-07-15 20:18 Darin.Johnson
2003-07-15 4:32 Eugene Surovegin
2003-07-15 15:46 ` Tom Rini
2003-07-15 16:20 ` Eugene Surovegin
2003-07-15 16:25 ` Tom Rini
2003-07-15 16:17 ` Matt Porter
2003-07-15 16:27 ` Eugene Surovegin
2003-07-15 23:51 ` Matt Porter
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