From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f199.google.com (mail-qt0-f199.google.com [209.85.216.199]) by kanga.kvack.org (Postfix) with ESMTP id 1557F6B0003 for ; Fri, 22 Jun 2018 14:47:02 -0400 (EDT) Received: by mail-qt0-f199.google.com with SMTP id d7-v6so5979066qth.21 for ; Fri, 22 Jun 2018 11:47:02 -0700 (PDT) Received: from mx1.redhat.com (mx3-rdu2.redhat.com. [66.187.233.73]) by mx.google.com with ESMTPS id g44-v6si4325104qtc.366.2018.06.22.11.46.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Jun 2018 11:46:59 -0700 (PDT) Date: Fri, 22 Jun 2018 14:46:58 -0400 (EDT) From: Mikulas Patocka Subject: Re: dm bufio: Reduce dm_bufio_lock contention In-Reply-To: <20180622131013.GA10465@dhcp22.suse.cz> Message-ID: References: <20180615073201.GB24039@dhcp22.suse.cz> <20180615115547.GH24039@dhcp22.suse.cz> <20180615130925.GI24039@dhcp22.suse.cz> <20180619104312.GD13685@dhcp22.suse.cz> <20180622090151.GS10465@dhcp22.suse.cz> <20180622131013.GA10465@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: jing xia , Mike Snitzer , agk@redhat.com, dm-devel@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Fri, 22 Jun 2018, Michal Hocko wrote: > On Fri 22-06-18 08:44:52, Mikulas Patocka wrote: > > On Fri, 22 Jun 2018, Michal Hocko wrote: > [...] > > > Why? How are you going to audit all the callers that the behavior makes > > > sense and moreover how are you going to ensure that future usage will > > > still make sense. The more subtle side effects gfp flags have the harder > > > they are to maintain. > > > > I did audit them - see the previous email in this thread: > > https://www.redhat.com/archives/dm-devel/2018-June/thread.html > > I do not see any mention about throttling expectations for those users. > You have focused only on the allocation failure fallback AFAIR How should the callers be analyzed with respect to throttling? Mikulas