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 40D53C433F5 for ; Wed, 27 Apr 2022 18:36:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 93A7C6B0074; Wed, 27 Apr 2022 14:36:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8EA206B0075; Wed, 27 Apr 2022 14:36:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7B1796B0078; Wed, 27 Apr 2022 14:36:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 6842A6B0074 for ; Wed, 27 Apr 2022 14:36:57 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 3B2592114C for ; Wed, 27 Apr 2022 18:36:57 +0000 (UTC) X-FDA: 79403515674.28.43CA38B Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf11.hostedemail.com (Postfix) with ESMTP id F01C94004C for ; Wed, 27 Apr 2022 18:36:53 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EDEB361ED7; Wed, 27 Apr 2022 18:36:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F7A4C385A9; Wed, 27 Apr 2022 18:36:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1651084615; bh=OMICTGO/WYqPH3eg8uS6ToJj8mhJ9pJAhueCepETYGw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mL5WuWxE1oAHwTgDVWF/ZSPjveU0MDpd5Uvw46vXoBCYn2+/LaKGjCRkzm4GlsAIM 7b/mKi2m9pR5S0iab7gFXcUa6WjTZ82mYZgSVkrTfOxFluiScSimCscnu58NstAxiI U9cw/bYMDrCdB3fqlz02HDDXeqW1WRZ9YtXIArtE= Date: Wed, 27 Apr 2022 11:36:54 -0700 From: Andrew Morton To: Johannes Weiner Cc: Michal Hocko , Roman Gushchin , Shakeel Butt , Seth Jennings , Dan Streetman , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 4/5] mm: zswap: add basic meminfo and vmstat coverage Message-Id: <20220427113654.ef8f543d7ba279952deff6f7@linux-foundation.org> In-Reply-To: <20220427160016.144237-5-hannes@cmpxchg.org> References: <20220427160016.144237-1-hannes@cmpxchg.org> <20220427160016.144237-5-hannes@cmpxchg.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=mL5WuWxE; dmarc=none; spf=pass (imf11.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: F01C94004C X-Rspam-User: X-Stat-Signature: kd8ttzjft98tusrpfcr47p6em6hojtir X-HE-Tag: 1651084613-875499 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 Wed, 27 Apr 2022 12:00:15 -0400 Johannes Weiner wrote: > Currently it requires poking at debugfs to figure out the size and > population of the zswap cache on a host. There are no counters for > reads and writes against the cache. As a result, it's difficult to > understand zswap behavior on production systems. > > Print zswap memory consumption and how many pages are zswapped out in > /proc/meminfo. Count zswapouts and zswapins in /proc/vmstat. /proc/meminfo is rather prime real estate. Is this important enough to be placed in there, or should it instead be in the more lowly /proc/vmstat? /proc/meminfo is documented in Documentation/filesystems/proc.rst ;) That file appears to need a bit of updating for other things.