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=-8.4 required=3.0 tests=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 8CF74C4BA01 for ; Tue, 25 Feb 2020 22:30:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4BE112176D for ; Tue, 25 Feb 2020 22:30:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FpPAphSH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BE112176D 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 DD3C66B0008; Tue, 25 Feb 2020 17:30:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D842E6B000C; Tue, 25 Feb 2020 17:30:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C9ACA6B000D; Tue, 25 Feb 2020 17:30:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0135.hostedemail.com [216.40.44.135]) by kanga.kvack.org (Postfix) with ESMTP id AF9BD6B0008 for ; Tue, 25 Feb 2020 17:30:16 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 51B8B40CD for ; Tue, 25 Feb 2020 22:30:16 +0000 (UTC) X-FDA: 76530094032.13.trade68_76c09a4aab801 X-HE-Tag: trade68_76c09a4aab801 X-Filterd-Recvd-Size: 3894 Received: from mail-ot1-f67.google.com (mail-ot1-f67.google.com [209.85.210.67]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Tue, 25 Feb 2020 22:30:15 +0000 (UTC) Received: by mail-ot1-f67.google.com with SMTP id i6so1082409otr.7 for ; Tue, 25 Feb 2020 14:30:15 -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=BrEPbLqTlFfWhG7c3GGQgt9yFg0pALuIdjeT0xABLMg=; b=FpPAphSHXLYsaE+3UvRxPBgDOnB7MzMk7Kmlh3zw4TOfEWCHWfGUJgRgDJ8VBkWILC fkPyQAdZf3U7B8Vug+ANb3jafZttPSBVWEuvQ+oaghABbjg7S+yasje27XW2Gu0fCaNu 89eHuQHxDrywCsMb3ncajsBSzC6mY0iFSYJBxqyDaIfWBePiwJr81FaFpJ9Zou6QkEyc Jjip7c/AKq914jb039x4fbGuobk8OlrDk3vD7f5J1zxZ3/H7tBDa0NLjdmJ08s2jnUhV wYGXLf+gK0mSec/DY3pPLGZVF60swBgnM79xrVAANmXb/r5JP1+NLcbk1UcVDSUMQnB6 Jmng== 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=BrEPbLqTlFfWhG7c3GGQgt9yFg0pALuIdjeT0xABLMg=; b=egdTTaX5llHsCH205fRE8wk0ntUqzzODwxMnoIMX+uJxQdaxMkj6c/XZO4KykgafQK SJc86dMLePpyVEw7b1wjJX+qFFB3a0Jhqn99N+UJpIX595K+HDsjpsdPNZQfohwerxmd 6GGSRLkEeu8Ds/I38oFdwhLSd16NRgUqTpJPepIok6l2jUB7GH4qSYUI/k3bmkvTh/t6 qIAgzkPrHV01PjCQ+T5P4jjInDTGTaJA2blW/JjVU7wHiWzz2YlKpwYDT6xok72iwNMI 2f9zWm+7tXOcJzKmQWKgFSd09I4F9Vgx3HUnRKe2DeuMeDDmKQ5DD8rTJ2K4jEnwQtD/ 0f6A== X-Gm-Message-State: APjAAAUC/mgx4hkUpu4tXvuaydWPDIRGg1WTf6fULmIjZUeBHQ1bP6pj ZitrLoQpKY6wpUi8b99hMNYFLik0V5oOXqeAcFoqjQ== X-Google-Smtp-Source: APXvYqxPfciH6Z5eK4o0F5Fulc1nBBSG9d5q8Wk5//UKojl8rjqHpyXrdfeCEpLJu+rhzG9/1VevJv49Kiuqtk+U318= X-Received: by 2002:a9d:6ac2:: with SMTP id m2mr630339otq.191.1582669814963; Tue, 25 Feb 2020 14:30:14 -0800 (PST) MIME-Version: 1.0 References: <20200219194006.GA3075@sultan-book.localdomain> <20200219200527.GF11847@dhcp22.suse.cz> <20200219204220.GA3488@sultan-book.localdomain> <20200219214513.GL3420@suse.de> <20200219224231.GA5190@sultan-book.localdomain> <20200220101945.GN3420@suse.de> <20200221042232.GA2197@sultan-book.localdomain> <20200221080737.GK20509@dhcp22.suse.cz> <20200221210824.GA3605@sultan-book.localdomain> <20200225090945.GJ22443@dhcp22.suse.cz> In-Reply-To: <20200225090945.GJ22443@dhcp22.suse.cz> From: Shakeel Butt Date: Tue, 25 Feb 2020 14:30:03 -0800 Message-ID: Subject: Re: [PATCH] mm: Stop kswapd early when nothing's waiting for it to free pages To: Michal Hocko Cc: Sultan Alsawaf , Mel Gorman , Dave Hansen , Andrew Morton , Linux MM , LKML , Johannes Weiner 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, Feb 25, 2020 at 1:10 AM Michal Hocko wrote: > [snip] > > The proper fix should, however, check the amount of reclaimable pages > and back off if they cannot meet the target IMO. We cannot rely on the > general reclaimability here because that could really be thrashing. > "check the amount of reclaimable pages" vs "cannot rely on the general reclaimability"? Can you clarify? BTW we are seeing a similar situation in our production environment. We have swappiness=0, no swap from kswapd (because we don't swapout on pressure, only on cold age) and too few file pages, the kswapd goes crazy on shrink_slab and spends 100% cpu on it. Shakeel