From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF4DBC2D0A3 for ; Tue, 3 Nov 2020 21:40:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3699720756 for ; Tue, 3 Nov 2020 21:40:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FdUvjbjL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3699720756 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B79D96B0068; Tue, 3 Nov 2020 16:40:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B2CB36B006C; Tue, 3 Nov 2020 16:40:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9F1D26B006E; Tue, 3 Nov 2020 16:40:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0202.hostedemail.com [216.40.44.202]) by kanga.kvack.org (Postfix) with ESMTP id 715506B0068 for ; Tue, 3 Nov 2020 16:40:54 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 124FC8249980 for ; Tue, 3 Nov 2020 21:40:54 +0000 (UTC) X-FDA: 77444427228.05.beam49_060cc3f272bb Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin05.hostedemail.com (Postfix) with ESMTP id E7C701802186D for ; Tue, 3 Nov 2020 21:40:53 +0000 (UTC) X-HE-Tag: beam49_060cc3f272bb X-Filterd-Recvd-Size: 4607 Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com [209.85.221.41]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Nov 2020 21:40:53 +0000 (UTC) Received: by mail-wr1-f41.google.com with SMTP id 33so9190744wrl.7 for ; Tue, 03 Nov 2020 13:40:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=UujFYQwrAMAwi1/OCKFtTp32QIC/tCBtqm1aq3KAJ18=; b=FdUvjbjLJoPJViFWAGZQTYBxNYPCG2lrEX+eW+1JbafAofaJfmaF34xRbhMStCu1bw Q8y8dUQmIvl4HybqP4JQ2sEemewRBCRFSV7WpefnD+epD106SUeDvcyPNvvMSuxqlAki eZy07p1662luyVqnaCsH8fMg+HsoFxrC3o3qXw4wGlXogHOm6XRfrRpwjkMHyttr4Pp9 c+ohCfM4BXsHV41o1jEPT10BBk6ZBWClev2C+qrSzLNS3y0o4TsTxRr9skWqurJOH1z9 3CAVCbPHbZkzJJeyW6Bkl2RQjSilQ/VXgfG0+nhgDaWQOq78Nm0zvZaB+n71rMEEQIDd rkQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=UujFYQwrAMAwi1/OCKFtTp32QIC/tCBtqm1aq3KAJ18=; b=A9hf/oz5LcVjW5b1CZDKdsWVzwxn/d/003wubA+Y7xQ5b/F7n9iGZEed/pTGqoBHTL wki+SY/YKVnJG9uxClzW6u206DHD2XK1G4L93pwn39FYchLWQPlJz30gBYvF2UtM7jkp WMaL5o7ZFpmhc4O+RG75woxSkqJRKUs0f1R3GLR2D+4W2vbjtuyY2oDgVsvk2hNvuAp1 vZE7RXm7DO1z+qBrJ1IRy4mzG0ApDZbASRMZ5x8nbav2vtmMCzURDpslDe6Tq0apf4bX ph7VNhAhcq+dNHM7VevOxu9kGona25ViR78Wb5j+RzrnRSxGGBawPnpsgOmAqFtQmMQX Rq7g== X-Gm-Message-State: AOAM532YeI0d0R7buNvNmovTfE0ZK0puuBmusiOVP2HpuF+1W0RcYTKH bd3tsTRRX6WOW3hXh3pHSxsq570BVrCZIRCwUBRJGg== X-Google-Smtp-Source: ABdhPJwwE5qbcx0FJgRwt8ysoKwO12F59BUj6qqo925IYvPZ1whgXvzlaDVmywWxSx45wVl1QcVcY4kSPyjBPA1lUQU= X-Received: by 2002:adf:a501:: with SMTP id i1mr27790501wrb.162.1604439651996; Tue, 03 Nov 2020 13:40:51 -0800 (PST) MIME-Version: 1.0 References: <20201014120937.GC4440@dhcp22.suse.cz> <20201015092030.GB22589@dhcp22.suse.cz> <20201103093550.GE21990@dhcp22.suse.cz> <20201103213228.GB1631979@google.com> In-Reply-To: <20201103213228.GB1631979@google.com> From: Suren Baghdasaryan Date: Tue, 3 Nov 2020 13:40:41 -0800 Message-ID: Subject: Re: [RFC]: userspace memory reaping To: Minchan Kim Cc: Michal Hocko , linux-api@vger.kernel.org, linux-mm , Andrew Morton , David Rientjes , Matthew Wilcox , Johannes Weiner , Roman Gushchin , Rik van Riel , Christian Brauner , Oleg Nesterov , Tim Murray , kernel-team , LKML , Mel Gorman Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Nov 3, 2020 at 1:32 PM Minchan Kim wrote: > > On Tue, Nov 03, 2020 at 10:35:50AM +0100, Michal Hocko wrote: > > On Mon 02-11-20 12:29:24, Suren Baghdasaryan wrote: > > [...] > > > To follow up on this. Should I post an RFC implementing SIGKILL_SYNC > > > which in addition to sending a kill signal would also reap the > > > victim's mm in the context of the caller? Maybe having some code will > > > get the discussion moving forward? > > > > Yeah, having a code, even preliminary, might help here. This definitely > > needs a good to go from process management people as that proper is land > > full of surprises... > > Just to remind a idea I suggested to reuse existing concept > > fd = pidfd_open(victim process) > fdatasync(fd); > close(fd); > Yep, I just posted a comment about that. I think though your above sequence is missing a pidfd_send_signal(fd, SIGKILL) before the fdatasync(fd)... Not sure if fdatasync(pidfd) or fsync(pidfd) would be more appropriate for this but will use one and we can discuss details in the RFC with the code. Thanks!