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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E0C1C433FE for ; Mon, 17 Oct 2022 22:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229976AbiJQWqa (ORCPT ); Mon, 17 Oct 2022 18:46:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229829AbiJQWq2 (ORCPT ); Mon, 17 Oct 2022 18:46:28 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F8597E820; Mon, 17 Oct 2022 15:46:27 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 231D71F8D1; Mon, 17 Oct 2022 22:46:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1666046786; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KPXn8oCISsFaCnRNyRjpdaEv1QQo5ZLAKB/NsLXVGBs=; b=NfKOqe4gHCl9/Htq5BcTbwrgFymKb4wGV1EoSbTVL1zMWiFBS0wESzuZBCcXi55G/gR0tQ dqkWXoDM2yaNsea3ydA79oc54ZMQO9pSGOy34tkFfc3j8hI+NmtNtlNXbV82hU2h+0y5E3 y7ohEeM0pH8mJna2Hkfzj+XLk/7aVQo= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id D387413ABE; Mon, 17 Oct 2022 22:46:25 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 7rDvMUHbTWN0YwAAMHmgww (envelope-from ); Mon, 17 Oct 2022 22:46:25 +0000 Date: Tue, 18 Oct 2022 00:46:24 +0200 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: Tejun Heo Cc: Waiman Long , Michal Hocko , Johannes Weiner , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Chris Down Subject: Re: [PATCH] mm/memcontrol: Don't increase effective low/min if no protection needed Message-ID: References: <20221011143015.1152968-1-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 11, 2022 at 07:04:32AM -1000, Tejun Heo wrote: > Wouldn't it make sense to fix the test? With recursive_prot on, the cgroup > actually is under low protection and it seems like the correct behavior is > to report the low events accordingly. It depends whether the there is a residual protection that the memory.low=0 sibling can use (with memory_recursiveprot). In the discussed LTP test, there should be no residual protection that would justify the apparently misreported memory.low events. I.e. the test is correct, the failure points to a subtle issue with distributing residual protection among siblings. Been there, (haven't) done that: 1) https://bugzilla.suse.com/show_bug.cgi?id=1196298 2) https://lore.kernel.org/r/20220325103118.GC2828@blackbody.suse.cz/ HTH, Michal