From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx105.postini.com [74.125.245.105]) by kanga.kvack.org (Postfix) with SMTP id 425356B006E for ; Fri, 8 Jun 2012 05:12:48 -0400 (EDT) From: Subject: RE: [PATCH 0/5] Some vmevent fixes... Date: Fri, 8 Jun 2012 09:12:36 +0000 Message-ID: <84FF21A720B0874AA94B46D76DB98269045F7B42@008-AM1MPN1-004.mgdnok.nokia.com> References: <20120601122118.GA6128@lizard> <4FCC7592.9030403@kernel.org> <20120604113811.GA4291@lizard> <4FCD14F1.1030105@gmail.com> <20120605083921.GA21745@lizard> <4FD014D7.6000605@kernel.org> <20120608074906.GA27095@lizard> <4FD1BB29.1050805@kernel.org> In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: penberg@kernel.org, minchan@kernel.org Cc: anton.vorontsov@linaro.org, kosaki.motohiro@gmail.com, john.stultz@linaro.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com > -----Original Message----- > From: penberg@gmail.com [mailto:penberg@gmail.com] On Behalf Of ext > Pekka Enberg > Sent: 08 June, 2012 11:48 > To: Minchan Kim ... >=20 > On Fri, Jun 8, 2012 at 11:43 AM, Minchan Kim wrote: > >> So, the solution would be then two-fold: > >> > >> 1. Use your memory pressure notifications. They must be quite fast > >> when > >> =A0 =A0we starting to feel the high pressure. (I see the you use > >> =A0 =A0zone_page_state() and friends, which is vm_stat, and it is upda= ted > > > > VM has other information like nr_reclaimed, nr_scanned, nr_congested, > > recent_scanned, recent_rotated, too. I hope we can make math by them > > and improve as we improve VM reclaimer. > > > >> =A0 =A0very infrequently, but to get accurate notification we have to > >> =A0 =A0update it much more frequently, but this is very expensive. So > >> =A0 =A0KOSAKI and Christoph will complain. :-) > > > > > > Reclaimer already have used that and if we need accuracy, we handled > > it like zone_watermark_ok_safe. If it's very inaccurate, VM should be f= ixed, > too. >=20 > Exactly. I don't know why people think pushing vmevents to userspace is > going to fix any of the hard problems. >=20 > Anton, Lenoid, do you see any fundamental issues from userspace point of > view with going forward what Minchan is proposing? That good proposal but I have to underline that userspace could be interest= ed not only in memory consumption stressed cases (pressure, vm watermarks O= N etc.)=20 but quite relaxed as well e.g. 60% durty pages are consumed - let's do not = restart some daemons. In very stressed conditions user-space might be alrea= dy dead. Another interesting question which combination of VM page types could be re= cognized as interesting for tracking as Minchan correctly stated it depends= from area. For me seems weights most likely will be -1, 0 or +1 to calculate resulting= values and thesholds e.g. Active =3D {+1 * Active_Anon; +1 * Active_File} It will extend flexibility a lot. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org