From: Pekka Enberg <penberg@kernel.org>
To: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>, linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
leonid.moiseichuk@nokia.com, kamezawa.hiroyu@jp.fujitsu.com,
mel@csn.ul.ie, rientjes@google.com,
KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Marcelo Tosatti <mtosatti@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Ronen Hod <rhod@redhat.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Subject: Re: [RFC 1/3] /dev/low_mem_notify
Date: Tue, 17 Jan 2012 21:49:13 +0200 [thread overview]
Message-ID: <CAOJsxLFzuvYm2pHZP--=nx3qGatzgfT6Dii49gzJwzxOtzniTg@mail.gmail.com> (raw)
In-Reply-To: <4F15CC56.90309@redhat.com>
On Tue, Jan 17, 2012 at 9:30 PM, Rik van Riel <riel@redhat.com> wrote:
> Looks like a nice extensible interface to me.
>
> The only thing is, I expect we will not want to wake
> up processes most of the time, when there is no memory
> pressure, because that would just waste battery power
> and/or cpu time that could be used for something else.
>
> The desire to avoid such wakeups makes it harder to
> wake up processes at arbitrary points set by the API.
Sure. You could either bump up the threshold or use Minchan's hooks - or both.
On Tue, Jan 17, 2012 at 9:30 PM, Rik van Riel <riel@redhat.com> wrote:
> Another issue is that we might be running two programs
> on the system, each with a different threshold for
> "lets free some of my cache". Say one program sets
> the threshold at 20% free/cache memory, the other
> program at 10%.
>
> We could end up with the first process continually
> throwing away its caches, while the second process
> never gives its unused memory back to the kernel.
>
> I am not sure what the right thing to do would be...
One option is to use per-process thresholds on RSS, for example, and
also support system-wide thresholds.
That said, I'd really like to see the N9 and Android policies
supported with this ABI. It's much easier to make it generic once we
support real-world use cases.
Pekka
next prev parent reply other threads:[~2012-01-17 19:49 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-17 8:13 [RFC 0/3] low memory notify Minchan Kim
2012-01-17 8:13 ` [RFC 1/3] /dev/low_mem_notify Minchan Kim
2012-01-17 9:27 ` Pekka Enberg
2012-01-17 16:35 ` Rik van Riel
2012-01-17 18:51 ` Pekka Enberg
2012-01-17 19:30 ` Rik van Riel
2012-01-17 19:49 ` Pekka Enberg [this message]
2012-01-17 19:54 ` Pekka Enberg
2012-01-17 19:57 ` Pekka Enberg
2012-01-17 23:20 ` Minchan Kim
2012-01-18 7:16 ` Pekka Enberg
2012-01-18 7:49 ` Minchan Kim
2012-01-18 9:06 ` leonid.moiseichuk
2012-01-18 9:15 ` Pekka Enberg
2012-01-18 9:41 ` leonid.moiseichuk
2012-01-18 10:40 ` Pekka Enberg
2012-01-18 10:44 ` leonid.moiseichuk
2012-01-18 23:34 ` Ronen Hod
2012-01-19 7:25 ` Pekka Enberg
2012-01-19 9:05 ` Ronen Hod
2012-01-19 9:10 ` Pekka Enberg
2012-01-19 9:20 ` Ronen Hod
2012-01-19 10:53 ` leonid.moiseichuk
2012-01-19 11:07 ` Pekka Enberg
2012-01-19 11:54 ` leonid.moiseichuk
2012-01-19 11:59 ` Pekka Enberg
2012-01-19 12:06 ` Pekka Enberg
2012-01-24 15:38 ` Marcelo Tosatti
2012-01-24 16:08 ` Ronen Hod
2012-01-24 18:10 ` Marcelo Tosatti
2012-01-25 8:52 ` Ronen Hod
2012-01-25 10:12 ` Marcelo Tosatti
2012-01-25 10:48 ` Ronen Hod
2012-01-26 16:17 ` Marcelo Tosatti
2012-01-24 16:10 ` Pekka Enberg
2012-01-24 18:29 ` Marcelo Tosatti
2012-01-25 8:19 ` leonid.moiseichuk
2012-01-19 7:34 ` Pekka Enberg
2012-01-24 16:22 ` Arnd Bergmann
2012-01-18 14:30 ` Rik van Riel
2012-01-18 15:29 ` Pekka Enberg
2012-01-24 15:40 ` Marcelo Tosatti
2012-01-24 16:01 ` Pekka Enberg
2012-01-24 16:25 ` Arnd Bergmann
2012-01-24 18:32 ` Marcelo Tosatti
2012-01-24 21:57 ` Jonathan Corbet
2012-01-17 9:45 ` Pekka Enberg
2012-01-17 8:13 ` [RFC 2/3] vmscan hook Minchan Kim
2012-01-17 8:39 ` KAMEZAWA Hiroyuki
2012-01-17 9:13 ` Minchan Kim
2012-01-17 10:05 ` KAMEZAWA Hiroyuki
2012-01-17 23:08 ` Minchan Kim
2012-01-18 0:18 ` KAMEZAWA Hiroyuki
2012-01-18 14:17 ` Rik van Riel
2012-01-19 2:25 ` KAMEZAWA Hiroyuki
2012-01-19 14:42 ` Rik van Riel
2012-01-20 0:24 ` KAMEZAWA Hiroyuki
2012-01-17 8:13 ` [RFC 3/3] test program Minchan Kim
2012-01-17 14:38 ` [RFC 0/3] low memory notify Colin Walters
2012-01-17 15:04 ` Pekka Enberg
2012-01-17 16:44 ` Rik van Riel
2012-01-17 17:16 ` Olof Johansson
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