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 72E4EC433EF for ; Wed, 24 Nov 2021 12:06:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234168AbhKXMJq (ORCPT ); Wed, 24 Nov 2021 07:09:46 -0500 Received: from shark4.inbox.lv ([194.152.32.84]:55624 "EHLO shark4.inbox.lv" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234102AbhKXMGu (ORCPT ); Wed, 24 Nov 2021 07:06:50 -0500 Received: from shark4.inbox.lv (localhost [127.0.0.1]) by shark4-out.inbox.lv (Postfix) with ESMTP id 6EBE5C0178; Wed, 24 Nov 2021 14:03:38 +0200 (EET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=inbox.lv; s=30062014; t=1637755418; bh=uswn3I7yKCxPCF1aTOeqCga4G4QdRDC7HAODYeFv594=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=l+rZ9MrZepDspl9ywUI9wcU7I3kWzUlyHmFIQnNaLcPusZuPcgmO7mRdgn++8HY27 zdxG7mw04bCo2Q0GBM3kgCz2b60ha+tJMe4P4AqeAQAkG2GRyh+QtARkF7FA6kwRaA 730g/9DrGn/ygPXKSBYHKc+yqkZUGJVc+E094Hd0= Received: from localhost (localhost [127.0.0.1]) by shark4-in.inbox.lv (Postfix) with ESMTP id 62F84C016E; Wed, 24 Nov 2021 14:03:38 +0200 (EET) Received: from shark4.inbox.lv ([127.0.0.1]) by localhost (shark4.inbox.lv [127.0.0.1]) (spamfilter, port 35) with ESMTP id RSopZvB9lvWL; Wed, 24 Nov 2021 14:03:38 +0200 (EET) Received: from mail.inbox.lv (pop1 [127.0.0.1]) by shark4-in.inbox.lv (Postfix) with ESMTP id 1C440C00AF; Wed, 24 Nov 2021 14:03:38 +0200 (EET) Received: from mail.inbox.lv (unknown [79.105.116.237]) (Authenticated sender: hakavlad@inbox.lv) by mail.inbox.lv (Postfix) with ESMTPA id 7F59B3E6014F; Wed, 24 Nov 2021 14:03:33 +0200 (EET) Date: Wed, 24 Nov 2021 21:03:20 +0900 From: Alexey Avramov To: Mel Gorman Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mhocko@suse.com, vbabka@suse.cz, neilb@suse.de, akpm@linux-foundation.org, corbet@lwn.net, riel@surriel.com, hannes@cmpxchg.org, david@fromorbit.com, willy@infradead.org, hdanton@sina.com, penguin-kernel@i-love.sakura.ne.jp, oleksandr@natalenko.name, kernel@xanmod.org, michael@michaellarabel.com, aros@gmx.com, hakavlad@gmail.com Subject: Re: mm: 5.16 regression: reclaim_throttle leads to stall in near-OOM conditions Message-ID: <20211124210320.591dd883@mail.inbox.lv> In-Reply-To: <20211124115007.GG3366@techsingularity.net> References: <20211124011954.7cab9bb4@mail.inbox.lv> <20211124103550.GE3366@techsingularity.net> <20211124195449.33f31e7f@mail.inbox.lv> <20211124115007.GG3366@techsingularity.net> X-Mailer: Claws Mail 3.14.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Virus-Scanned: OK X-ESPOL: AJ2EQ38cmnBBsMa9LpgflO6Go8rKNlcktDn7zrgu6HNfqLHCtMIXA2KUEpicZw/5LSPD Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >but can you test this? I have already tested different parameters, and found that even zero timeout is unsatisfactory. The introduction of reclaim_throttle() itself dramatically worsens the stall in near-OOM. More info: https://lore.kernel.org/lkml/20211124011954.7cab9bb4@mail.inbox.lv/ What test else I should perform? Okay, on one side of the scale is the use of the CPU, on the other side is the risk of stall. My dissatisfaction is caused by the fact that the scale has now tipped sharply in favor of stall. Although even before this change, users complained about the inability to wait for OOM: https://lore.kernel.org/lkml/d9802b6a-949b-b327-c4a6-3dbca485ec20@gmx.com/