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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 57735C43381 for ; Tue, 12 Mar 2019 15:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26AD42054F for ; Tue, 12 Mar 2019 15:25:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="AOvHnDX1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726663AbfCLPZq (ORCPT ); Tue, 12 Mar 2019 11:25:46 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:58712 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725894AbfCLPZq (ORCPT ); Tue, 12 Mar 2019 11:25:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=OAThpFYHfFpJdEy8OwLPNDdww7fmMTYYWyenN4Id6uo=; b=AOvHnDX1lDeBOkejHAgtcES98 maDyEJIbh2t0zujM6b1FKExleWlsQr9ryaTezc2F7EGc7u5iLKFyUKAZt9V0EjkBysvW1PlEps+O0 qGt6i68gN15lovw3xoNxGU2FqsVKU0FpIcGbsogl0lu64m87a7E5ZMT1PIsXOOxBecMp8i5D4/kmB ZThuHfu/oIyz5uRfHh0N3RZRTcRwEjSPvrIEbfIbzRlDWkPmLveIeC9Z4QCSAi6IjN8kE+v9iOU52 x7cXj+QX1JvdxblwYJwnWvHlo6Cdyr6VVLyBsXNYJaFL/+CWtkiBDA/ZyiaVMBOc+JwkWseRE7qzF LVUBGt8hA==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1h3jHh-0004rb-E5; Tue, 12 Mar 2019 15:25:41 +0000 Date: Tue, 12 Mar 2019 08:25:41 -0700 From: Matthew Wilcox To: Michal Hocko Cc: Suren Baghdasaryan , Sultan Alsawaf , Greg Kroah-Hartman , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Ingo Molnar , Peter Zijlstra , LKML , devel@driverdev.osuosl.org, linux-mm , Tim Murray Subject: Re: [RFC] simple_lmk: Introduce Simple Low Memory Killer for Android Message-ID: <20190312152541.GI19508@bombadil.infradead.org> References: <20190310203403.27915-1-sultan@kerneltoast.com> <20190311174320.GC5721@dhcp22.suse.cz> <20190311175800.GA5522@sultan-box.localdomain> <20190311204626.GA3119@sultan-box.localdomain> <20190312080532.GE5721@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190312080532.GE5721@dhcp22.suse.cz> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 12, 2019 at 09:05:32AM +0100, Michal Hocko wrote: > On Mon 11-03-19 15:15:35, Suren Baghdasaryan wrote: > > Yeah, killing speed is a well-known problem which we are considering > > in LMKD. For example the recent LMKD change to assign process being > > killed to a cpuset cgroup containing big cores cuts the kill time > > considerably. This is not ideal and we are thinking about better ways > > to expedite the cleanup process. > > If you design is relies on the speed of killing then it is fundamentally > flawed AFAICT. You cannot assume anything about how quickly a task dies. > It might be blocked in an uninterruptible sleep or performin an > operation which takes some time. Sure, oom_reaper might help here but > still. Many UNINTERRUPTIBLE sleeps can be converted to KILLABLE sleeps. It just needs someone to do the work.