From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 14AC86B01AF for ; Thu, 14 May 2009 08:34:35 -0400 (EDT) Received: by gxk20 with SMTP id 20so2382344gxk.14 for ; Thu, 14 May 2009 05:35:07 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20090514210839.9B90.A69D9226@jp.fujitsu.com> References: <20090514204033.9B87.A69D9226@jp.fujitsu.com> <28c262360905140505h2db7ac3bp5ca10fcf2b4301bb@mail.gmail.com> <20090514210839.9B90.A69D9226@jp.fujitsu.com> Date: Thu, 14 May 2009 21:35:07 +0900 Message-ID: <28c262360905140535w4bfdbbccp55f395daa18fbf0e@mail.gmail.com> Subject: Re: [PATCH] mmtom: Prevent shrinking of active anon lru list in case of no swap space V2 From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Andrew Morton , LKML , linux-mm , Johannes Weiner , Rik van Riel List-ID: On Thu, May 14, 2009 at 9:11 PM, KOSAKI Motohiro wrote: >> On Thu, May 14, 2009 at 8:44 PM, KOSAKI Motohiro >> wrote: >> >> > >> >> > Changelog since V2 >> >> > ?o Add new function - can_reclaim_anon : it tests anon_list can be = reclaim >> >> > >> >> > Changelog since V1 >> >> > ?o Use nr_swap_pages <=3D 0 in shrink_active_list to prevent scanni= ng ?of active anon list. >> >> > >> >> > Now shrink_active_list is called several places. >> >> > But if we don't have a swap space, we can't reclaim anon pages. >> >> > So, we don't need deactivating anon pages in anon lru list. >> >> > >> >> > Signed-off-by: Minchan Kim >> >> > Cc: KOSAKI Motohiro >> >> > Cc: Johannes Weiner >> >> > Cc: Rik van Riel >> >> >> >> looks good to me. thanks :) >> > >> > Grr, my fault. >> > >> > >> > >> >> ?static unsigned long shrink_list(enum lru_list lru, unsigned long nr= _to_scan, >> >> ? ? ? struct zone *zone, struct scan_control *sc, int priority) >> >> ?{ >> >> @@ -1399,7 +1412,7 @@ static unsigned long shrink_list(enum lru_list = lru, unsigned long nr_to_scan, >> >> ? ? ? ? ? ? ? return 0; >> >> ? ? ? } >> >> >> >> - ? ? if (lru =3D=3D LRU_ACTIVE_ANON && inactive_anon_is_low(zone, sc= )) { >> >> + ? ? if (lru =3D=3D LRU_ACTIVE_ANON && can_reclaim_anon(zone, sc)) { >> >> ? ? ? ? ? ? ? shrink_active_list(nr_to_scan, zone, sc, priority, file= ); >> >> ? ? ? ? ? ? ? return 0; >> > >> > you shouldn't do that. if nr_swap_pages=3D=3D0, get_scan_ratio return = anon=3D0%. >> > then, this branch is unnecessary. >> > >> >> But, I think at last it can be happen following as. >> >> 1515 =C2=A0 =C2=A0 =C2=A0 =C2=A0 * Even if we did not try to evict anon = pages at all, we want to >> 1516 =C2=A0 =C2=A0 =C2=A0 =C2=A0 * rebalance the anon lru active/inactiv= e ratio. >> 1517 =C2=A0 =C2=A0 =C2=A0 =C2=A0 */ >> 1518 =C2=A0 =C2=A0 =C2=A0 =C2=A0if (inactive_anon_is_low(zone, sc)) >> 1519 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0shrink_activ= e_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0); > > I pointed to shrink_list(), but you replayed shrink_zone(). > I only talked about shrink_list(). > In shrink_zone, we call get_scan_ratio. it prevent scanning anon list. but, in shrink_all_zones can't prevent it. Also, I think shrink_list is not hot patch. So check of one condition adding is trivial If I don't understand your point, please explain detaily --=20 Kinds regards, Minchan Kim -- 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