From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: Re: [PATCH RFC] mm/memcontrol: reclaim severe usage over high limit in get_user_pages loop Date: Mon, 29 Jul 2019 20:48:50 +0200 Message-ID: <20190729184850.GH9330@dhcp22.suse.cz> References: <156431697805.3170.6377599347542228221.stgit@buzz> <20190729091738.GF9330@dhcp22.suse.cz> <3d6fc779-2081-ba4b-22cf-be701d617bb4@yandex-team.ru> <20190729103307.GG9330@dhcp22.suse.cz> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yang Shi Cc: Konstantin Khlebnikov , Linux MM , Linux Kernel Mailing List , cgroups@vger.kernel.org, Vladimir Davydov , Johannes Weiner On Mon 29-07-19 10:28:43, Yang Shi wrote: [...] > I don't worry too much about scale since the scale issue is not unique > to background reclaim, direct reclaim may run into the same problem. Just to clarify. By scaling problem I mean 1:1 kswapd thread to memcg. You can have thousands of memcgs and I do not think we really do want to create one kswapd for each. Once we have a kswapd thread pool then we get into a tricky land where a determinism/fairness would be non trivial to achieve. Direct reclaim, on the other hand is bound by the workload itself. -- Michal Hocko SUSE Labs