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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 8064FC3A59F for ; Thu, 29 Aug 2019 12:29:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 482BB2189D for ; Thu, 29 Aug 2019 12:29:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567081753; bh=DcYrTwuhvE3ZTyaWeowmkN5S3XcPaOJeLDBSFTuhcEE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=iCz66XAS5eY6EgEE2wgYxRPKAuwUJI7Lqy1TW8lCPnJCstcOWDkK5zE3ZRVrRxFyd w3I3seQ8eSvvV0fSBtTqm8h4jeCO22H5ihMBeBpb86KA2BT11GQCBpXbdRnuUDgsmA AZmCiEii9qWERZV9y46CSz3C8EhAEYxv4RE5hirk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727025AbfH2M3M (ORCPT ); Thu, 29 Aug 2019 08:29:12 -0400 Received: from mx2.suse.de ([195.135.220.15]:35468 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725782AbfH2M3M (ORCPT ); Thu, 29 Aug 2019 08:29:12 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D8B80AC97; Thu, 29 Aug 2019 12:29:10 +0000 (UTC) Date: Thu, 29 Aug 2019 14:29:09 +0200 From: Michal Hocko To: James Courtier-Dutton Cc: Daniel Drake , "Artem S. Tashkinov" , LKML Mailing List , linux@endlessm.com, hadess@hadess.net, Johannes Weiner Subject: Re: Let's talk about the elephant in the room - the Linux kernel's inability to gracefully handle low memory pressure Message-ID: <20190829122909.GG28313@dhcp22.suse.cz> References: <20190820064620.5119-1-drake@endlessm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 21-08-19 22:42:29, James Courtier-Dutton wrote: > On Tue, 20 Aug 2019 at 07:47, Daniel Drake wrote: > > > > Hi, > > > > And if there is a meaningful way to make the kernel behave better, that would > > obviously be of huge value too. > > > > Thanks > > Daniel > > Hi, > > Is there a way for an application to be told that there is a memory > pressure situation? PSI (CONFIG_PSI) measures global as well as per memcg pressure characteristics. [...] > I have also found, for the desktop, one of the biggest pressures on > the system is disk pressure. Accessing the disk causes the UI to be > less responsive. > For example, if I am in vim, and trying to type letters on the > keyboard, whether some other application is using the disk or not > should have no impact on my letter writing. Has anyone got any ideas > with regards to what we can do about that? This is what we have the page cache for. -- Michal Hocko SUSE Labs