From: Christoph Lameter <cl@linux-foundation.org>
To: Rik van Riel <riel@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>, David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mel@csn.ul.ie>,
stable@kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Frans Pop <elendil@planet.nl>,
Jiri Kosina <jkosina@suse.cz>,
Sven Geggus <lists@fuchsschwanzdomain.de>,
Karol Lewandowski <karol.k.lewandowski@gmail.com>,
Tobias Oetiker <tobi@oetiker.ch>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Pekka Enberg <penberg@cs.helsinki.fi>,
Stephan von Krawczynski <skraw@ithnet.com>,
kernel-testers@vger.kernel.org
Subject: Re: [PATCH 2/3] page allocator: Do not allow interrupts to use ALLOC_HARDER
Date: Mon, 2 Nov 2009 11:42:36 -0500 (EST) [thread overview]
Message-ID: <alpine.DEB.1.10.0911021139100.24535@V090114053VZO-1> (raw)
In-Reply-To: <4AECCF6A.4020206@redhat.com>
On Sat, 31 Oct 2009, Rik van Riel wrote:
> On 10/31/2009 04:11 PM, Pavel Machek wrote:
>
> > But we can't guarantee that enough memory will be ready in the
> > reserves. So if realtime task relies on it, it is broken, and will
> > fail to meet its deadlines from time to time.
>
> Any realtime task that does networking (which may be the
> majority of realtime tasks) relies on the kernel memory
> allocator.
What is realtime in this scenario? There are no guarantees that reclaim
wont have to occur. There are no guarantees anymore and therefore you
cannot really call this realtime.
Is realtime anything more than: "I want to have my patches merged"?
Give some criteria as to what realtime is please. I am all for decreasing
kernel latencies. But some of this work is adding bloat and increasing
overhead.
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next prev parent reply other threads:[~2009-11-02 16:43 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-27 13:40 [PATCH 0/3] Reduce GFP_ATOMIC allocation failures, partial fix V3 Mel Gorman
2009-10-27 13:40 ` [PATCH 1/3] page allocator: Always wake kswapd when restarting an allocation attempt after direct reclaim failed Mel Gorman
2009-10-27 13:40 ` [PATCH 2/3] page allocator: Do not allow interrupts to use ALLOC_HARDER Mel Gorman
[not found] ` <1256650833-15516-3-git-send-email-mel-wPRd99KPJ+uzQB+pC5nmwQ@public.gmane.org>
2009-10-27 20:09 ` Andrew Morton
2009-10-27 21:12 ` David Rientjes
2009-10-31 18:40 ` Pavel Machek
2009-10-31 19:51 ` David Rientjes
2009-10-31 20:11 ` Pavel Machek
2009-10-31 21:19 ` David Rientjes
2009-10-31 22:29 ` Pavel Machek
2009-10-31 22:55 ` Rik van Riel
2009-11-01 7:35 ` Pavel Machek
2009-11-01 12:37 ` KOSAKI Motohiro
2009-11-01 14:44 ` Rik van Riel
2009-11-01 19:32 ` Pavel Machek
2009-11-02 16:38 ` Christoph Lameter
2009-10-31 23:59 ` Rik van Riel
2009-11-02 16:42 ` Christoph Lameter [this message]
2009-11-02 20:53 ` David Rientjes
2009-11-03 17:10 ` Christoph Lameter
2009-11-04 1:46 ` David Rientjes
2009-11-04 9:01 ` Pavel Machek
2009-11-09 10:11 ` Mel Gorman
2009-10-28 10:24 ` Mel Gorman
2009-10-27 13:40 ` [PATCH 3/3] vmscan: Force kswapd to take notice faster when high-order watermarks are being hit Mel Gorman
2009-10-27 18:18 ` Rik van Riel
2009-10-27 20:19 ` Andrew Morton
2009-10-28 3:54 ` KOSAKI Motohiro
2009-10-28 10:29 ` Mel Gorman
2009-10-28 19:47 ` Andrew Morton
2009-11-02 16:05 ` Mel Gorman
2009-11-02 17:32 ` Frans Pop
2009-11-02 17:38 ` Mel Gorman
2009-11-02 20:36 ` Mel Gorman
2009-11-03 22:01 ` Frans Pop
2009-11-03 22:08 ` Mel Gorman
2009-11-04 0:01 ` Frans Pop
2009-11-04 1:18 ` Mel Gorman
2009-11-04 2:05 ` Frans Pop
2009-11-04 2:08 ` Frans Pop
2009-11-04 15:48 ` Mel Gorman
2009-11-04 20:57 ` Frans Pop
2009-11-05 16:48 ` [PATCH 3/3] vmscan: Force kswapd to take notice faster when high-order watermarks are being hit (data on latencies available) Mel Gorman
2009-11-12 11:36 ` Frans Pop
2009-11-04 2:08 ` [PATCH 3/3] vmscan: Force kswapd to take notice faster when high-order watermarks are being hit Mel Gorman
2009-10-28 13:02 ` [PATCH 0/3] Reduce GFP_ATOMIC allocation failures, partial fix V3 Karol Lewandowski
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