From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH 04/14] net: tcp_memcontrol: remove bogus hierarchy pressure propagation Date: Fri, 20 Nov 2015 12:07:25 +0300 Message-ID: <20151120090725.GW31308@esperanza> References: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> <1447371693-25143-5-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: <1447371693-25143-5-git-send-email-hannes@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: Content-Transfer-Encoding: 7bit To: Johannes Weiner Cc: David Miller , Andrew Morton , Tejun Heo , Michal Hocko , netdev@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com On Thu, Nov 12, 2015 at 06:41:23PM -0500, Johannes Weiner wrote: > When a cgroup currently breaches its socket memory limit, it enters > memory pressure mode for itself and its *ancestors*. This throttles > transmission in unrelated sibling and cousin subtrees that have > nothing to do with the breached limit. > > On the contrary, breaching a limit should make that group and its > *children* enter memory pressure mode. But this happens already, > albeit lazily: if an ancestor limit is breached, siblings will enter > memory pressure on their own once the next packet arrives for them. Hmm, we still call sk_prot->enter_memory_pressure, which might hurt a workload in the root cgroup AFAICS. Strange. You fix it in patch 8 though. > > So no additional hierarchy code is needed. Remove the bogus stuff. > > Signed-off-by: Johannes Weiner Reviewed-by: Vladimir Davydov -- 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 S1162488AbbKTJIA (ORCPT ); Fri, 20 Nov 2015 04:08:00 -0500 Received: from mx2.parallels.com ([199.115.105.18]:50603 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162451AbbKTJHo (ORCPT ); Fri, 20 Nov 2015 04:07:44 -0500 Date: Fri, 20 Nov 2015 12:07:25 +0300 From: Vladimir Davydov To: Johannes Weiner CC: David Miller , Andrew Morton , Tejun Heo , Michal Hocko , , , , , Subject: Re: [PATCH 04/14] net: tcp_memcontrol: remove bogus hierarchy pressure propagation Message-ID: <20151120090725.GW31308@esperanza> References: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> <1447371693-25143-5-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1447371693-25143-5-git-send-email-hannes@cmpxchg.org> X-ClientProxiedBy: US-EXCH.sw.swsoft.com (10.255.249.47) To US-EXCH2.sw.swsoft.com (10.255.249.46) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 12, 2015 at 06:41:23PM -0500, Johannes Weiner wrote: > When a cgroup currently breaches its socket memory limit, it enters > memory pressure mode for itself and its *ancestors*. This throttles > transmission in unrelated sibling and cousin subtrees that have > nothing to do with the breached limit. > > On the contrary, breaching a limit should make that group and its > *children* enter memory pressure mode. But this happens already, > albeit lazily: if an ancestor limit is breached, siblings will enter > memory pressure on their own once the next packet arrives for them. Hmm, we still call sk_prot->enter_memory_pressure, which might hurt a workload in the root cgroup AFAICS. Strange. You fix it in patch 8 though. > > So no additional hierarchy code is needed. Remove the bogus stuff. > > Signed-off-by: Johannes Weiner Reviewed-by: Vladimir Davydov From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH 04/14] net: tcp_memcontrol: remove bogus hierarchy pressure propagation Date: Fri, 20 Nov 2015 12:07:25 +0300 Message-ID: <20151120090725.GW31308@esperanza> References: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> <1447371693-25143-5-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: David Miller , Andrew Morton , Tejun Heo , Michal Hocko , , , , , To: Johannes Weiner Return-path: Content-Disposition: inline In-Reply-To: <1447371693-25143-5-git-send-email-hannes@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-Id: netdev.vger.kernel.org On Thu, Nov 12, 2015 at 06:41:23PM -0500, Johannes Weiner wrote: > When a cgroup currently breaches its socket memory limit, it enters > memory pressure mode for itself and its *ancestors*. This throttles > transmission in unrelated sibling and cousin subtrees that have > nothing to do with the breached limit. > > On the contrary, breaching a limit should make that group and its > *children* enter memory pressure mode. But this happens already, > albeit lazily: if an ancestor limit is breached, siblings will enter > memory pressure on their own once the next packet arrives for them. Hmm, we still call sk_prot->enter_memory_pressure, which might hurt a workload in the root cgroup AFAICS. Strange. You fix it in patch 8 though. > > So no additional hierarchy code is needed. Remove the bogus stuff. > > Signed-off-by: Johannes Weiner Reviewed-by: Vladimir Davydov -- 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