From: Peter Zijlstra <peterz@infradead.org>
To: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>,
"Siddha, Suresh B" <suresh.b.siddha@intel.com>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
ak@suse.de, gregkh@suse.de, muli@il.ibm.com, ashok.raj@intel.com,
davem@davemloft.net, clameter@sgi.com
Subject: Re: [Intel IOMMU 06/10] Avoid memory allocation failures in dma map api calls
Date: Thu, 21 Jun 2007 09:13:11 +0200 [thread overview]
Message-ID: <1182409991.21117.112.camel@twins> (raw)
In-Reply-To: <20070621063730.GC6771@linux-os.sc.intel.com>
On Wed, 2007-06-20 at 23:37 -0700, Keshavamurthy, Anil S wrote:
> On Thu, Jun 21, 2007 at 08:29:34AM +0200, Peter Zijlstra wrote:
> > On Wed, 2007-06-20 at 23:11 -0700, Arjan van de Ven wrote:
> > > Peter Zijlstra wrote:
> > Also, the other iommu code you pointed me to, was happy to fail, it did
> > not attempt to use the emergency reserves.
>
> Is the same behavior acceptable here?
I would say it is. Failure is a part of life.
If you have a (small) mempool with 16 pages or so, that should give you
plenty megabytes of io-space to get out of a tight spot. That is, you
can queue many pages with that. If it is depleted you know you have at
least that many pages outstanding. So failing will just delay the next
pages.
Throughput is not a key issue when that low on memory, a guarantee of
progress is.
next prev parent reply other threads:[~2007-06-21 7:13 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-19 21:37 [Intel IOMMU 00/10] Intel IOMMU support, take #2 Keshavamurthy, Anil S
2007-06-19 21:37 ` [Intel IOMMU 01/10] DMAR detection and parsing logic Keshavamurthy, Anil S
2007-07-04 9:18 ` Peter Zijlstra
2007-07-04 10:04 ` Andrew Morton
2007-07-04 10:14 ` Peter Zijlstra
2007-06-19 21:37 ` [Intel IOMMU 02/10] PCI generic helper function Keshavamurthy, Anil S
2007-06-26 5:49 ` Andrew Morton
2007-06-26 14:44 ` Keshavamurthy, Anil S
2007-06-19 21:37 ` [Intel IOMMU 03/10] clflush_cache_range now takes size param Keshavamurthy, Anil S
2007-06-19 21:37 ` [Intel IOMMU 04/10] IOVA allocation and management routines Keshavamurthy, Anil S
2007-06-26 6:07 ` Andrew Morton
2007-06-26 16:16 ` Keshavamurthy, Anil S
2007-06-19 21:37 ` [Intel IOMMU 05/10] Intel IOMMU driver Keshavamurthy, Anil S
2007-06-19 23:32 ` Christoph Lameter
2007-06-19 23:50 ` Keshavamurthy, Anil S
2007-06-19 23:56 ` Christoph Lameter
2007-06-26 6:32 ` Andrew Morton
2007-06-26 16:29 ` Keshavamurthy, Anil S
2007-06-26 6:25 ` Andrew Morton
2007-06-26 16:33 ` Keshavamurthy, Anil S
2007-06-26 6:30 ` Andrew Morton
2007-06-19 21:37 ` [Intel IOMMU 06/10] Avoid memory allocation failures in dma map api calls Keshavamurthy, Anil S
2007-06-19 23:25 ` Christoph Lameter
2007-06-19 23:27 ` Arjan van de Ven
2007-06-19 23:34 ` Christoph Lameter
2007-06-20 0:02 ` Arjan van de Ven
2007-06-20 8:06 ` Peter Zijlstra
2007-06-20 13:03 ` Arjan van de Ven
2007-06-20 17:30 ` Siddha, Suresh B
2007-06-20 18:05 ` Peter Zijlstra
2007-06-20 19:14 ` Arjan van de Ven
2007-06-20 20:08 ` Peter Zijlstra
2007-06-20 23:03 ` Keshavamurthy, Anil S
2007-06-21 6:10 ` Peter Zijlstra
2007-06-21 6:11 ` Arjan van de Ven
2007-06-21 6:29 ` Peter Zijlstra
2007-06-21 6:37 ` Keshavamurthy, Anil S
2007-06-21 7:13 ` Peter Zijlstra [this message]
2007-06-21 19:51 ` Keshavamurthy, Anil S
2007-06-21 6:30 ` Keshavamurthy, Anil S
2007-06-26 5:34 ` Andrew Morton
2007-06-19 21:37 ` [Intel IOMMU 07/10] Intel iommu cmdline option - forcedac Keshavamurthy, Anil S
2007-06-19 21:37 ` [Intel IOMMU 08/10] DMAR fault handling support Keshavamurthy, Anil S
2007-06-19 21:37 ` [Intel IOMMU 09/10] Iommu Gfx workaround Keshavamurthy, Anil S
2007-06-19 21:37 ` [Intel IOMMU 10/10] Iommu floppy workaround Keshavamurthy, Anil S
2007-06-26 6:42 ` Andrew Morton
2007-06-26 10:37 ` Andi Kleen
2007-06-26 19:25 ` Keshavamurthy, Anil S
2007-06-26 16:26 ` Keshavamurthy, Anil S
2007-06-26 6:45 ` [Intel IOMMU 00/10] Intel IOMMU support, take #2 Andrew Morton
2007-06-26 7:12 ` Andi Kleen
2007-06-26 11:13 ` Muli Ben-Yehuda
2007-06-26 15:03 ` Arjan van de Ven
2007-06-26 15:11 ` Muli Ben-Yehuda
2007-06-26 15:48 ` Keshavamurthy, Anil S
2007-06-26 16:00 ` Muli Ben-Yehuda
2007-06-26 15:56 ` Andi Kleen
2007-06-26 15:09 ` Muli Ben-Yehuda
2007-06-26 15:36 ` Andi Kleen
2007-06-26 15:15 ` Arjan van de Ven
2007-06-26 15:33 ` Andi Kleen
2007-06-26 16:25 ` Arjan van de Ven
2007-06-26 17:31 ` Andi Kleen
2007-06-26 20:10 ` Jesse Barnes
2007-06-26 22:35 ` Andi Kleen
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