From: "Albert D. Cahalan" <acahalan@cs.uml.edu>
To: Oliver.Neukum@lrz.uni-muenchen.de (Oliver Neukum)
Cc: davem@redhat.com (David S. Miller), linux-kernel@vger.kernel.org
Subject: Re: PCI DMA to small buffers on cache-incoherent arch
Date: Sun, 9 Jun 2002 02:57:26 -0400 (EDT) [thread overview]
Message-ID: <200206090657.g596vQj403167@saturn.cs.uml.edu> (raw)
In-Reply-To: <200206090644.g596iMX14841@fachschaft.cup.uni-muenchen.de> from "Oliver Neukum" at Jun 09, 2002 08:50:04 AM
Oliver Neukum writes:
>> For memory --> device DMA:
>>
>> 1. write back all cache lines affected by the DMA
>> 2. start the DMA
>> 3. invalidate the above cache lines
>
> Why the third step ? That data should still
> be valid.
I made a mistake, but perhaps it is a good one.
There is no need to invalidate the cache lines,
but I'd guess that commonly the data won't be
used again. Doing the invalidate would free up
some cache lines, meaning that the CPU would
have empty slots to use for other stuff.
next prev parent reply other threads:[~2002-06-09 6:57 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-06-08 20:38 Roland Dreier
2002-06-08 13:58 ` Anton Blanchard
2002-06-09 0:52 ` Roland Dreier
2002-06-08 23:03 ` David S. Miller
2002-06-09 0:40 ` Roland Dreier
2002-06-09 0:53 ` David S. Miller
2002-06-09 1:26 ` Roland Dreier
2002-06-09 5:29 ` David S. Miller
2002-06-09 6:16 ` Roland Dreier
2002-06-10 16:03 ` Roland Dreier
2002-06-11 14:04 ` David Woodhouse
2002-06-09 6:45 ` Oliver Neukum
2002-06-10 4:24 ` David S. Miller
2002-06-10 10:00 ` Oliver Neukum
2002-06-10 10:24 ` David S. Miller
2002-06-09 9:51 ` Paul Mackerras
2002-06-09 10:54 ` Benjamin Herrenschmidt
2002-06-10 4:27 ` David S. Miller
2002-06-10 15:59 ` Roland Dreier
2002-06-10 17:03 ` Tom Rini
2002-06-10 17:22 ` Oliver Neukum
2002-06-10 17:29 ` Tom Rini
2002-06-10 17:39 ` Oliver Neukum
2002-06-10 19:03 ` Roland Dreier
2002-06-10 19:14 ` Tom Rini
2002-06-10 19:21 ` Roland Dreier
2002-06-10 19:26 ` Tom Rini
2002-06-10 17:57 ` Russell King
2002-06-10 17:28 ` Roland Dreier
2002-06-10 18:07 ` William Jhun
2002-06-10 18:29 ` William Jhun
2002-06-10 18:33 ` Mark Zealey
2002-06-10 18:44 ` Oliver Neukum
2002-06-11 3:10 ` David S. Miller
2002-06-11 4:04 ` Roland Dreier
2002-06-11 4:16 ` Brad Hards
2002-06-11 4:24 ` Roland Dreier
2002-06-11 4:24 ` David S. Miller
2002-06-11 4:21 ` David S. Miller
2002-06-11 4:39 ` Roland Dreier
2002-06-11 4:38 ` David S. Miller
2002-06-11 6:23 ` Oliver Neukum
2002-06-11 6:38 ` David S. Miller
2002-06-11 7:38 ` Oliver Neukum
2002-06-11 7:36 ` David S. Miller
2002-06-11 7:43 ` David S. Miller
2002-06-11 8:07 ` Oliver Neukum
2002-06-11 8:15 ` David S. Miller
2002-06-11 12:06 ` Oliver Neukum
2002-06-11 12:04 ` David S. Miller
2002-06-11 14:23 ` Oliver Neukum
2002-06-14 4:14 ` David S. Miller
2002-06-11 18:26 ` Roland Dreier
2002-06-11 17:29 ` Benjamin Herrenschmidt
2002-06-12 12:02 ` Oliver Neukum
2002-06-11 20:06 ` Benjamin Herrenschmidt
2002-06-12 12:02 ` David S. Miller
2002-06-11 23:00 ` Thunder from the hill
2002-06-11 23:56 ` Roland Dreier
2002-06-12 0:09 ` Thunder from the hill
2002-06-11 15:57 ` William Jhun
2002-06-12 9:06 ` Pavel Machek
2002-06-12 20:16 ` David S. Miller
2002-06-12 11:47 ` David S. Miller
2002-06-12 12:08 ` Oliver Neukum
2002-06-14 4:41 ` David S. Miller
2002-06-12 16:09 ` William Jhun
2002-06-09 1:30 ` Albert D. Cahalan
2002-06-09 5:29 ` David S. Miller
2002-06-09 6:33 ` Albert D. Cahalan
2002-06-09 6:50 ` Oliver Neukum
2002-06-09 6:57 ` Albert D. Cahalan [this message]
2002-06-09 7:15 ` Oliver Neukum
2002-06-09 8:48 ` Russell King
2002-06-09 15:42 ` Albert D. Cahalan
2002-06-09 23:26 ` Oliver Neukum
2002-06-11 5:31 David Brownell
2002-06-11 5:44 ` David S. Miller
2002-06-11 15:12 ` David Brownell
2002-06-11 15:44 ` Oliver Neukum
2002-06-12 3:25 ` David S. Miller
2002-06-11 17:33 ` Benjamin Herrenschmidt
2002-06-12 9:42 ` David S. Miller
2002-06-12 14:14 ` David Brownell
2002-06-12 15:00 ` Benjamin Herrenschmidt
2002-06-12 18:44 ` Roland Dreier
2002-06-12 19:13 ` David Brownell
2002-06-12 19:58 ` Oliver Neukum
2002-06-12 22:51 ` David S. Miller
2002-06-12 23:17 ` Oliver Neukum
2002-06-13 4:57 ` David Brownell
2002-06-12 22:46 ` David S. Miller
2002-06-13 5:13 ` David Brownell
2002-06-13 9:38 ` David S. Miller
2002-06-12 22:50 ` David S. Miller
2002-06-12 6:25 ` David Brownell
2002-06-12 6:24 ` David S. Miller
2002-06-12 7:06 ` David Brownell
2002-06-12 9:22 ` David S. Miller
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