From: James Bottomley <James.Bottomley@SteelEye.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Matthew Wilcox <matthew@wil.cx>, Jeremy Higdon <jeremy@sgi.com>,
Grant Grundler <grundler@parisc-linux.org>,
Jesse Barnes <jbarnes@engr.sgi.com>,
Matthew Wilcox <willy@debian.org>,
Andrew Vasquez <andrew.vasquez@qlogic.com>,
pj@sgi.com, SCSI Mailing List <linux-scsi@vger.kernel.org>,
mdr@cthulhu.engr.sgi.com, jeremy@cthulhu.engr.sgi.com,
djh@cthulhu.engr.sgi.com, Andrew Morton <akpm@osdl.org>,
Richard Henderson <rth@twiddle.net>,
Paul Mackerras <paulus@samba.org>
Subject: Re: I/O write ordering
Date: 22 Sep 2004 11:11:24 -0400 [thread overview]
Message-ID: <1095865892.1715.5.camel@mulgrave> (raw)
In-Reply-To: <1095864709.6297.5.camel@gaston>
On Wed, 2004-09-22 at 10:51, Benjamin Herrenschmidt wrote:
> Read & write barriers are different for IO. Actually, as I stated earlier,
> the real issue isn't much with IO barriers proper (which are mostly dealt
> with within the implementation of the IO accessors), but in IO vs. memory
> accesses, at least on PPC. Cacheable and non-cacheable accesses go through
> completely different path on the CPU and can be completely re-ordered one
> to each other unless more heavy barriers are used. That has been a pain
> for ages for us since Linux doesn't provide an abstraction to order those,
> it would be nice to get that in place now ;)
Just to be sure we're talking about the same thing; by cacheable and
non-cacheable are you thinking about what PCI calls consistent and
streaming (because your consistent memory is implemented as
non-cacheable) or is this really the fact that PCI memory space as seen
by the CPU is all uncacheable?
James
next prev parent reply other threads:[~2004-09-22 15:11 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <B179AE41C1147041AA1121F44614F0B060EF48@AVEXCH02.qlogic.org>
[not found] ` <20040916121235.5e4f9c32.pj@sgi.com>
[not found] ` <1095362263.16326.12.camel@praka>
2004-09-16 19:56 ` SCSI QLA not working on latest *-mm SN2 Paul Jackson
2004-09-16 20:05 ` Jesse Barnes
2004-09-16 20:56 ` Andrew Vasquez
2004-09-16 21:09 ` Jesse Barnes
2004-09-16 21:40 ` Andrew Vasquez
2004-09-16 22:25 ` Andrew Morton
2004-09-16 22:29 ` Jesse Barnes
2004-09-17 17:21 ` Jesse Barnes
2004-09-18 6:10 ` Grant Grundler
2004-09-18 17:57 ` Documentation/io_ordering.txt is wrong Matthew Wilcox
2004-09-20 23:39 ` Jesse Barnes
2004-09-21 0:38 ` Jesse Barnes
2004-09-20 22:40 ` SCSI QLA not working on latest *-mm SN2 Jesse Barnes
2004-09-20 23:27 ` Grant Grundler
2004-09-21 0:09 ` Jesse Barnes
2004-09-21 5:46 ` Grant Grundler
2004-09-21 6:45 ` Jeremy Higdon
2004-09-21 13:29 ` Jesse Barnes
2004-09-21 13:25 ` Jesse Barnes
2004-09-21 15:13 ` Jesse Barnes
2004-09-21 15:41 ` James Bottomley
2004-09-21 15:58 ` Jesse Barnes
2004-09-21 16:01 ` Matthew Wilcox
2004-09-21 16:05 ` Jesse Barnes
2004-09-21 16:11 ` James Bottomley
2004-09-21 16:18 ` Jesse Barnes
2004-09-21 16:24 ` James Bottomley
2004-09-21 17:03 ` Jesse Barnes
2004-09-21 17:15 ` Matthew Wilcox
2004-09-21 17:24 ` Jesse Barnes
2004-09-21 17:20 ` James Bottomley
2004-09-21 17:46 ` Jesse Barnes
2004-09-21 17:56 ` James Bottomley
2004-09-21 18:09 ` Jesse Barnes
2004-09-21 19:06 ` Grant Grundler
2004-09-21 19:40 ` Jesse Barnes
2004-09-21 22:44 ` Grant Grundler
2004-09-21 21:03 ` Jeremy Higdon
2004-09-21 21:11 ` Matthew Wilcox
2004-09-21 21:43 ` Jeremy Higdon
2004-09-21 22:33 ` Jesse Barnes
2004-09-22 0:02 ` Matthew Wilcox
2004-09-22 1:16 ` Jeremy Higdon
2004-09-22 1:44 ` Grant Grundler
2004-09-22 2:58 ` Jeremy Higdon
2004-09-22 14:32 ` I/O write ordering Matthew Wilcox
2004-09-22 14:40 ` Benjamin Herrenschmidt
2004-09-22 14:50 ` Jesse Barnes
2004-09-22 14:47 ` James Bottomley
2004-09-22 14:51 ` Benjamin Herrenschmidt
2004-09-22 15:11 ` James Bottomley [this message]
2004-09-22 15:11 ` Benjamin Herrenschmidt
2004-09-22 15:22 ` James Bottomley
2004-09-22 15:28 ` Benjamin Herrenschmidt
2004-09-22 15:43 ` James Bottomley
2004-09-23 0:19 ` Benjamin Herrenschmidt
2004-09-23 1:58 ` Matthew Wilcox
2004-09-23 3:01 ` James Bottomley
2004-09-23 3:40 ` Benjamin Herrenschmidt
2004-09-23 4:26 ` Grant Grundler
2004-09-21 23:03 ` SCSI QLA not working on latest *-mm SN2 Guennadi Liakhovetski
2004-09-16 23:14 ` Jeremy Higdon
2004-09-16 20:11 ` Andrew Morton
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