From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH 7/8] mm: vmscan: report vmpressure at the level of reclaim activity Date: Thu, 22 Oct 2015 21:48:53 +0300 Message-ID: <20151022184852.GP18351@esperanza> References: <1445487696-21545-1-git-send-email-hannes@cmpxchg.org> <1445487696-21545-8-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <1445487696-21545-8-git-send-email-hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Transfer-Encoding: 7bit To: Johannes Weiner Cc: "David S. Miller" , Andrew Morton , Michal Hocko , Tejun Heo , netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Thu, Oct 22, 2015 at 12:21:35AM -0400, Johannes Weiner wrote: ... > @@ -2437,6 +2439,10 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } > > + vmpressure(sc->gfp_mask, memcg, > + sc->nr_scanned - scanned, > + sc->nr_reclaimed - reclaimed); > + > /* > * Direct reclaim and kswapd have to scan all memory > * cgroups to fulfill the overall scan target for the > @@ -2454,10 +2460,6 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } while ((memcg = mem_cgroup_iter(root, memcg, &reclaim))); > > - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, > - sc->nr_scanned - nr_scanned, > - sc->nr_reclaimed - nr_reclaimed); > - > if (sc->nr_reclaimed - nr_reclaimed) > reclaimable = true; > I may be mistaken, but AFAIU this patch subtly changes the behavior of vmpressure visible from the userspace: w/o this patch a userspace process will only receive a notification for a memory cgroup only if *this* memory cgroup calls reclaimer; with this patch userspace notification will be issued even if reclaimer is invoked by any cgroup up the hierarchy. Thanks, Vladimir From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f47.google.com (mail-lf0-f47.google.com [209.85.215.47]) by kanga.kvack.org (Postfix) with ESMTP id 589066B0038 for ; Thu, 22 Oct 2015 14:49:08 -0400 (EDT) Received: by lffv3 with SMTP id v3so58827950lff.0 for ; Thu, 22 Oct 2015 11:49:07 -0700 (PDT) Received: from relay.parallels.com (relay.parallels.com. [195.214.232.42]) by mx.google.com with ESMTPS id jv8si10447147lbc.86.2015.10.22.11.49.07 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Oct 2015 11:49:07 -0700 (PDT) Date: Thu, 22 Oct 2015 21:48:53 +0300 From: Vladimir Davydov Subject: Re: [PATCH 7/8] mm: vmscan: report vmpressure at the level of reclaim activity Message-ID: <20151022184852.GP18351@esperanza> References: <1445487696-21545-1-git-send-email-hannes@cmpxchg.org> <1445487696-21545-8-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1445487696-21545-8-git-send-email-hannes@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: "David S. Miller" , Andrew Morton , Michal Hocko , Tejun Heo , netdev@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org On Thu, Oct 22, 2015 at 12:21:35AM -0400, Johannes Weiner wrote: ... > @@ -2437,6 +2439,10 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } > > + vmpressure(sc->gfp_mask, memcg, > + sc->nr_scanned - scanned, > + sc->nr_reclaimed - reclaimed); > + > /* > * Direct reclaim and kswapd have to scan all memory > * cgroups to fulfill the overall scan target for the > @@ -2454,10 +2460,6 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } while ((memcg = mem_cgroup_iter(root, memcg, &reclaim))); > > - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, > - sc->nr_scanned - nr_scanned, > - sc->nr_reclaimed - nr_reclaimed); > - > if (sc->nr_reclaimed - nr_reclaimed) > reclaimable = true; > I may be mistaken, but AFAIU this patch subtly changes the behavior of vmpressure visible from the userspace: w/o this patch a userspace process will only receive a notification for a memory cgroup only if *this* memory cgroup calls reclaimer; with this patch userspace notification will be issued even if reclaimer is invoked by any cgroup up the hierarchy. Thanks, Vladimir -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965647AbbJVStL (ORCPT ); Thu, 22 Oct 2015 14:49:11 -0400 Received: from relay.parallels.com ([195.214.232.42]:47586 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965394AbbJVStI (ORCPT ); Thu, 22 Oct 2015 14:49:08 -0400 Date: Thu, 22 Oct 2015 21:48:53 +0300 From: Vladimir Davydov To: Johannes Weiner CC: "David S. Miller" , Andrew Morton , Michal Hocko , Tejun Heo , , , , Subject: Re: [PATCH 7/8] mm: vmscan: report vmpressure at the level of reclaim activity Message-ID: <20151022184852.GP18351@esperanza> References: <1445487696-21545-1-git-send-email-hannes@cmpxchg.org> <1445487696-21545-8-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1445487696-21545-8-git-send-email-hannes@cmpxchg.org> X-ClientProxiedBy: US-EXCH.sw.swsoft.com (10.255.249.47) To MSK-EXCH1.sw.swsoft.com (10.67.48.55) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 22, 2015 at 12:21:35AM -0400, Johannes Weiner wrote: ... > @@ -2437,6 +2439,10 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } > > + vmpressure(sc->gfp_mask, memcg, > + sc->nr_scanned - scanned, > + sc->nr_reclaimed - reclaimed); > + > /* > * Direct reclaim and kswapd have to scan all memory > * cgroups to fulfill the overall scan target for the > @@ -2454,10 +2460,6 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } while ((memcg = mem_cgroup_iter(root, memcg, &reclaim))); > > - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, > - sc->nr_scanned - nr_scanned, > - sc->nr_reclaimed - nr_reclaimed); > - > if (sc->nr_reclaimed - nr_reclaimed) > reclaimable = true; > I may be mistaken, but AFAIU this patch subtly changes the behavior of vmpressure visible from the userspace: w/o this patch a userspace process will only receive a notification for a memory cgroup only if *this* memory cgroup calls reclaimer; with this patch userspace notification will be issued even if reclaimer is invoked by any cgroup up the hierarchy. Thanks, Vladimir From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH 7/8] mm: vmscan: report vmpressure at the level of reclaim activity Date: Thu, 22 Oct 2015 21:48:53 +0300 Message-ID: <20151022184852.GP18351@esperanza> References: <1445487696-21545-1-git-send-email-hannes@cmpxchg.org> <1445487696-21545-8-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: "David S. Miller" , Andrew Morton , Michal Hocko , Tejun Heo , , , , To: Johannes Weiner Return-path: Content-Disposition: inline In-Reply-To: <1445487696-21545-8-git-send-email-hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org On Thu, Oct 22, 2015 at 12:21:35AM -0400, Johannes Weiner wrote: ... > @@ -2437,6 +2439,10 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } > > + vmpressure(sc->gfp_mask, memcg, > + sc->nr_scanned - scanned, > + sc->nr_reclaimed - reclaimed); > + > /* > * Direct reclaim and kswapd have to scan all memory > * cgroups to fulfill the overall scan target for the > @@ -2454,10 +2460,6 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > } > } while ((memcg = mem_cgroup_iter(root, memcg, &reclaim))); > > - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, > - sc->nr_scanned - nr_scanned, > - sc->nr_reclaimed - nr_reclaimed); > - > if (sc->nr_reclaimed - nr_reclaimed) > reclaimable = true; > I may be mistaken, but AFAIU this patch subtly changes the behavior of vmpressure visible from the userspace: w/o this patch a userspace process will only receive a notification for a memory cgroup only if *this* memory cgroup calls reclaimer; with this patch userspace notification will be issued even if reclaimer is invoked by any cgroup up the hierarchy. Thanks, Vladimir