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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 323D6C7EE23 for ; Wed, 1 Mar 2023 23:48:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B51906B0078; Wed, 1 Mar 2023 18:48:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B01F46B007E; Wed, 1 Mar 2023 18:48:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9C8EF6B0080; Wed, 1 Mar 2023 18:48:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8D4E96B0078 for ; Wed, 1 Mar 2023 18:48:09 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 5DB541202C5 for ; Wed, 1 Mar 2023 23:48:09 +0000 (UTC) X-FDA: 80521970298.27.99EC084 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) by imf03.hostedemail.com (Postfix) with ESMTP id 7979520015 for ; Wed, 1 Mar 2023 23:48:06 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=GpXkbFhc; spf=pass (imf03.hostedemail.com: domain of minchan.kim@gmail.com designates 209.85.214.180 as permitted sender) smtp.mailfrom=minchan.kim@gmail.com; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1677714486; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=IwnplCZss/sjev7Hh27BVil2zDjq9ax06z63d9E4vYY=; b=f5sV0quOTftDyb3aQK3qf1ESoCOIQPViJlcwtNMaUhFwbiSOJb41e9PXEVfiSao26N2ZLK W3/FnF2rmW75kFMwdi3t69PJQinUgw4K0NhnKBBhp3iM/OhwYRmxgtvt2ZYsOXsnSYiI89 8w8LQ2n/dT87r6xiaUmPs/UkhCmyagU= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=GpXkbFhc; spf=pass (imf03.hostedemail.com: domain of minchan.kim@gmail.com designates 209.85.214.180 as permitted sender) smtp.mailfrom=minchan.kim@gmail.com; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1677714486; a=rsa-sha256; cv=none; b=hMFPnOYVy0XCJYzgMi2tzS6Ljh4NBArNMP20i+9VnqBTObAa39u197AbYWrK1FaADsD+IQ CO4YWFNJwOLA3Jivp6Hr3gEPZVk4zHFC8S2IG8frev51J2QGx7s4M9CM4mvKjUsUItglz5 iiOxx1NiAQYlUhCVlSNVurFrwP5/wNU= Received: by mail-pl1-f180.google.com with SMTP id p20so14561096plw.13 for ; Wed, 01 Mar 2023 15:48:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1677714485; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=IwnplCZss/sjev7Hh27BVil2zDjq9ax06z63d9E4vYY=; b=GpXkbFhcR+YXAEC9td8Szq1ZMuyjfpUMKgB3P7Odc6nMN5mfl0uTGmcLq0dXc6aZbw NJo/SFk/ew1uJxyY0A7dFEH1PB/VS2EVoiFeQ+To0sYD/SHzmkYoWZKgkoVfwIpZMdzv E65W+sp9Dv1nLfD+oVddXYTwqnL2X7iF05ZPNUnhMc5P90tKkAiwFAEYd791K3crES7/ ITr6nrUXbr4q1Fj+kyjGKPNQ3pRUMpKf2i7pUQJNUgftNwUPMz8yfCgqRni3YfBIniS6 evhwQ6sOHdJkAqmTL8me0I/YtNWeWWL09O3vDTcgzadkCCOTh8Sb9U4vYPIJ46SAVdKN 5coQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1677714485; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=IwnplCZss/sjev7Hh27BVil2zDjq9ax06z63d9E4vYY=; b=Cbyl+kOhbp2qWoupNYBodOXKeQ/vtX+utkvao6rpgHdUYe+wZUSXoJeARYi6oSxIbj OqBeBAldSlEBuDOtR/hRVnLZGPf5DSLXbhtM3yA2gJ4eP7hSU5lMW4DkI9klxCy0lwki sKBw9XMlp0hDZFcSC49kHUb/1M5hv61EUewGPFDnKcdRwRuLTsFimXEf2ldM03k8bL+t eUq82/XIymrJkiHlxgd78GSCuCg88Bmz+eiJqSV9D/2IGKqclP8zIIiNl04w1UszUA6W jqlT3m6uxcVmpxkNTksZTmWSdpPpH9RXgygp8OUJwJlSGPq3w2EGBHV1i4Qx/WzRrUCQ PxeQ== X-Gm-Message-State: AO0yUKVxMvUwC6YwONRXAQ0W5axaI1lA6in/yYvA0oQtNFRVSz3c9hNg VsoG+t4RfRiK9DxYNMO6Kfs= X-Google-Smtp-Source: AK7set8pm9GVZz+CiwcKtVsULeY275AftnO/TM3U50O74RuKS7xCbHJ/5t6tVSe791ZyGMKLJbgcyA== X-Received: by 2002:a05:6a20:8407:b0:cc:eb3b:56e9 with SMTP id c7-20020a056a20840700b000cceb3b56e9mr11850682pzd.1.1677714485139; Wed, 01 Mar 2023 15:48:05 -0800 (PST) Received: from google.com ([2620:15c:211:201:a524:71b8:ce7e:745d]) by smtp.gmail.com with ESMTPSA id f23-20020aa782d7000000b005dea362ed18sm8497558pfn.27.2023.03.01.15.48.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Mar 2023 15:48:04 -0800 (PST) Date: Wed, 1 Mar 2023 15:48:02 -0800 From: Minchan Kim To: Sergey Senozhatsky Cc: Andrew Morton , Yosry Ahmed , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv2 5/6] zsmalloc: extend compaction statistics Message-ID: References: <20230223030451.543162-1-senozhatsky@chromium.org> <20230223030451.543162-6-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: s1usr8jdgd5dgbk9a3wumgaq3m3dzoiu X-Rspam-User: X-Rspamd-Queue-Id: 7979520015 X-Rspamd-Server: rspam06 X-HE-Tag: 1677714486-246842 X-HE-Meta: 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 XvIwKuDX D2YJE714Nm0KWWm3Ir2juuFoGDyXfUkxXd9UGw9diBZK4gDrNMn7dIoxraBXI/fJicpOoiSS26SnAPHFQTgSPRgsOcD11pBw7plYNs2Wy5eyLca5yH0eWdK3HdTjixFr4Hjal8HNxpxLq6whOTnuKHaxHO2DEBawwrja0wiRtSZOwAmEoR2pGkiI27/iqZxJkd/CifpTExsel3CmDGMQRPhg2kT7tU9WxiDz0U1qH/d/0gVpYX4YVl15I6XPR9dA5bs5Q3TWC2aeHZ/SM5OMFA7putTpmOsNPtu32xat9bmNMHDIv+WWwXrjSCGgkoRTr29EhnLJgvkA+LoFu9RAHGqQM7J5QU0PY6EhCu6sP638JKjqCUdQjfzg5Cpt/7qkevKuVRJJBnD4ElYNJa8qhMv9u9PsUZdOTAhk2okgXq4HGrl/M2y/HQ6puy+zjU7KWe3rXHk4v8TT+uv+t8zkkUZmJbG371ljZMLwIzpCvNY/2DWWb6MiCEHqJzolFpxnjL8rBcMqkphHyr+gkGFXtaSF042IbCPqlvhoGrZBKvyhmGzM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.015694, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Mar 01, 2023 at 12:54:56PM +0900, Sergey Senozhatsky wrote: > On (23/02/28 14:20), Minchan Kim wrote: > > On Sun, Feb 26, 2023 at 12:55:45PM +0900, Sergey Senozhatsky wrote: > > > On (23/02/23 15:51), Minchan Kim wrote: > > > > On Thu, Feb 23, 2023 at 12:04:50PM +0900, Sergey Senozhatsky wrote: > > > > > Extend zsmalloc zs_pool_stats with a new member that > > > > > holds the number of objects pool compaction moved > > > > > between pool pages. > > > > > > > > I totally understand this new stat would be very useful for your > > > > development but not sure it's really useful for workload tune or > > > > monitoring. > > > > > > > > Unless we have strong usecase, I'd like to avoid new stat. > > > > > > The way I see is that it *can* give some interesting additional data to > > > periodical compaction (the one is not triggeed by the shrinker): if the > > > number of moves objects is relatively high but the number of comapcted > > > (feeed) pages is relatively low then the system has fragmentation in > > > small size classes (that tend to have many objects per zspage but not > > > too many pages per zspage) and in this case the interval between > > > periodical compactions probably can be increased. What do you think? > > > > In the case, how could we get only data triggered by periodical munual > > compaction? > > Something very simple like > > read zram mm_stat > trigger comapction > read zram mm_stat > > can work in most cases, I guess. There can be memory pressure > and shrinkers can compact the pool concurrently, in which case > mm_stat will include shrinker impact, but that's probably not > a problem. If system is under memory pressure then user space Agreed. > in general does not have to do comapction, since the kernel will > handle it. > > Just an idea. It feels like "pages compacted" on its own tells very > little, but I don't insist on exporting that new stat. I don't mind adding the simple metric but I want to add metric if we have real usecase with handful of comments how they uses it in real world. Thanks.