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 5F914C433F5 for ; Wed, 27 Apr 2022 22:12:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232822AbiD0WPh (ORCPT ); Wed, 27 Apr 2022 18:15:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232674AbiD0WPd (ORCPT ); Wed, 27 Apr 2022 18:15:33 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 802D886E32; Wed, 27 Apr 2022 15:12:20 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id z21so2476560pgj.1; Wed, 27 Apr 2022 15:12:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=XXb42XiH+ukC9z7j3bBup8sRRl4KaGc4g7+LlMYSHsA=; b=Ws495q2rl2PRGj/zVnW5ZArxK3DYt6X/R641/Rg4daUGK5XREH0QoEi3vo4dOrnylv nP3eMrTlYZWHRUyOoBu/xrKPZ2+lmrhsSlg9egRevjW/NgcxcSBcwPi27LwUCBj6owub kcJkjnYF1BYOUc2SQz1i21KiLaGf3zKZxIK9Ff5IoHm/vhFuwWVc1xa15T7n334wy8Xf fMRPixKczaNFkniv3DoL5k3q+7DL86Pig/zQIONH8YyaTzxbDMqHdPA16yAu/5RKeusa dOse573kLTyhajewwEJzfifVdlrEfSxKvsC87iTJ29vMlS+9nttNB572LQsHcf9BbcKF zD+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=XXb42XiH+ukC9z7j3bBup8sRRl4KaGc4g7+LlMYSHsA=; b=4D4k41OTZVCGm3XJQ9Sewmvsg7jjVRvDrHZUJS7Ym6vW7V0/+k6hEnOIBHgmfRgR2+ M6CtBVvJGWkQgrAFEFvm68gMwsDr2mkHbdPpla5Wu7u5MGA3BEDkdbg3ThHG1iyJ5l/a 2eiX4XCkyXcKMc1NpNh+vIw2CeE0KodiqfW1Qtx9QsEjmHKdleTAzjfi1a7hh95vHH/A 0NQxEwElYTksV/aGED/r4uIXaMWyoJgOTNWsG4RUBGHEVP9wJZ5yLQXFvan9sCJw99X6 LsPy3M2gBH4Cq4xr1He0owDWNDByKTMQaAIFge6IP7ZaNJHT7wU10UbYPvCzc/don4yv WRgw== X-Gm-Message-State: AOAM530iZzgwLfd/58eWFCNRbwGNxM5++MG/3Tl7B2Lm63yluh619ez2 0AlO8hoTZh6FoIS0OeTmXmI= X-Google-Smtp-Source: ABdhPJzwmVF1HrfAv/PhFstcfrhOoUkpUM8r6eZpLrOQwgydnwT6oOkkV1+/wj3E5aYvB2gTl78USw== X-Received: by 2002:a63:2266:0:b0:39c:f643:ee69 with SMTP id t38-20020a632266000000b0039cf643ee69mr25066170pgm.288.1651097539917; Wed, 27 Apr 2022 15:12:19 -0700 (PDT) Received: from google.com ([2620:15c:211:201:546a:2875:2a75:1b94]) by smtp.gmail.com with ESMTPSA id 18-20020a17090a1a1200b001da160621d1sm3693495pjk.45.2022.04.27.15.12.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Apr 2022 15:12:19 -0700 (PDT) Sender: Minchan Kim Date: Wed, 27 Apr 2022 15:12:17 -0700 From: Minchan Kim To: Johannes Weiner Cc: Andrew Morton , 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: References: <20220427160016.144237-1-hannes@cmpxchg.org> <20220427160016.144237-5-hannes@cmpxchg.org> 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 Wed, Apr 27, 2022 at 05:36:26PM -0400, Johannes Weiner wrote: > On Wed, Apr 27, 2022 at 05:20:31PM -0400, Johannes Weiner wrote: > > On Wed, Apr 27, 2022 at 01:29:34PM -0700, Minchan Kim wrote: > > > Hi Johannes, > > > > > > On Wed, Apr 27, 2022 at 12:00:15PM -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. > > > > > > > > Signed-off-by: Johannes Weiner > > > > --- > > > > fs/proc/meminfo.c | 7 +++++++ > > > > include/linux/swap.h | 5 +++++ > > > > include/linux/vm_event_item.h | 4 ++++ > > > > mm/vmstat.c | 4 ++++ > > > > mm/zswap.c | 13 ++++++------- > > > > 5 files changed, 26 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c > > > > index 6fa761c9cc78..6e89f0e2fd20 100644 > > > > --- a/fs/proc/meminfo.c > > > > +++ b/fs/proc/meminfo.c > > > > @@ -86,6 +86,13 @@ static int meminfo_proc_show(struct seq_file *m, void *v) > > > > > > > > show_val_kb(m, "SwapTotal: ", i.totalswap); > > > > show_val_kb(m, "SwapFree: ", i.freeswap); > > > > +#ifdef CONFIG_ZSWAP > > > > + seq_printf(m, "Zswap: %8lu kB\n", > > > > + (unsigned long)(zswap_pool_total_size >> 10)); > > > > + seq_printf(m, "Zswapped: %8lu kB\n", > > > > + (unsigned long)atomic_read(&zswap_stored_pages) << > > > > + (PAGE_SHIFT - 10)); > > > > +#endif > > > > > > I agree it would be very handy to have the memory consumption in meminfo > > > > > > https://lore.kernel.org/all/YYwZXrL3Fu8%2FvLZw@google.com/ > > > > > > If we really go this Zswap only metric instead of general term > > > "Compressed", I'd like to post maybe "Zram:" with same reason > > > in this patchset. Do you think that's better idea instead of > > > introducing general term like "Compressed:" or something else? > > > > I'm fine with changing it to Compressed. If somebody cares about a > > more detailed breakdown, we can add Zswap, Zram subsets as needed. > > It does raise the question what to do about cgroup, though. Should the > control files (memory.zswap.current & memory.zswap.max) apply to zram > in the future? If so, we should rename them, too. > > I'm not too familiar with zram, maybe you can provide some > background. AFAIU, Google uses zram quite widely; all the more > confusing why there is no container support for it yet. My usecase with zram is Android which doesn't use memcg.