From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Brauner Subject: Re: [PATCH] Add prctl support for controlling mem reclaim V4 Date: Mon, 27 Jan 2020 14:02:59 +0100 Message-ID: <20200127130258.2bknkl3mwpkfyml4@wittgenstein> References: <20191112001900.9206-1-mchristi@redhat.com> <5E2B19C9.6080907@redhat.com> <20200124211642.GB7216@dread.disaster.area> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20200124211642.GB7216@dread.disaster.area> Sender: linux-scsi-owner@vger.kernel.org To: Dave Chinner Cc: Mike Christie , Shakeel Butt , Andrew Morton , linux-api@vger.kernel.org, idryomov@gmail.com, Michal Hocko , Linux MM , LKML , linux-scsi@vger.kernel.org, linux-fsdevel , linux-block@vger.kernel.org, martin@urbackup.org, Damien.LeMoal@wdc.com, Michal Hocko , Masato Suzuki List-Id: linux-api@vger.kernel.org On Sat, Jan 25, 2020 at 08:16:42AM +1100, Dave Chinner wrote: > On Fri, Jan 24, 2020 at 10:22:33AM -0600, Mike Christie wrote: > > On 12/05/2019 04:43 PM, Shakeel Butt wrote: > > > On Mon, Nov 11, 2019 at 4:19 PM Mike Christie wrote: > > >> This patch adds a new prctl command that daemons can use after they have > > >> done their initial setup, and before they start to do allocations that > > >> are in the IO path. It sets the PF_MEMALLOC_NOIO and PF_LESS_THROTTLE > > >> flags so both userspace block and FS threads can use it to avoid the > > >> allocation recursion and try to prevent from being throttled while > > >> writing out data to free up memory. > > >> > > >> Signed-off-by: Mike Christie > > >> Acked-by: Michal Hocko > > >> Tested-by: Masato Suzuki > > >> Reviewed-by: Damien Le Moal > > > > > > I suppose this patch should be routed through MM tree, so, CCing Andrew. > > > > > > > Andrew and other mm/storage developers, > > > > Do I need to handle anything else for this patch, or are there any other > > concerns? Is this maybe something we want to talk about at a quick LSF > > session? > > > > I have retested it with Linus's current tree. It still applies cleanly > > (just some offsets), and fixes the problem described above we have been > > hitting. > > I must have missed this version being posted (just looked it up on > lore.kernel.org). As far as I'm concerned this is good to go and it > is absolutely necessary for userspace IO stacks to function > correctly. > > Reviewed-by: Dave Chinner > > If no manintainer picks it up before the next merge window, then I Since prctl() is thread-management and fs people seem to be happy and have acked it I can pick this up too if noone objects and send this along with the rest of process management. Christian