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 CE4F5C433F5 for ; Thu, 28 Apr 2022 14:26:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348339AbiD1O3x (ORCPT ); Thu, 28 Apr 2022 10:29:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347045AbiD1O3w (ORCPT ); Thu, 28 Apr 2022 10:29:52 -0400 Received: from mail-qk1-x72b.google.com (mail-qk1-x72b.google.com [IPv6:2607:f8b0:4864:20::72b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBF373EF38 for ; Thu, 28 Apr 2022 07:26:36 -0700 (PDT) Received: by mail-qk1-x72b.google.com with SMTP id j9so3736340qkg.1 for ; Thu, 28 Apr 2022 07:26:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=k2xk0VfPUZZR4PgPEBFE7KbYEWH+FmFopnCFIlm7PdU=; b=BV94KuxAotFnCW2rpxR5ikP/WxESDoIazAhKPFkO1eGzDxo7hawOoKkHC0UbhoIeQy kZg8jfkxgeybcxSbVkPKyf/R8j319H1hEEjldKPErEBwufuhSw5mT4aclDQzGTGmOQ4z vfMoivqIpG4ELDuBcZ0Lo3UjNSF9EOuclEjFk4kMkAuHZnXHnZGbiU71bRjNAWpZoXdE OVtUxqBbeYfV85GYLzG9DEZSYCi7JYWgpRIAP4TxPtab35D28kaePo90gYcCyWnoTDSJ nh0zCTTwNRYmmxH3C3h+6DAcalHEbjnTNIOcg75fSF6dIHkflMcrL1mdWIN+kjqV2eZ+ euow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=k2xk0VfPUZZR4PgPEBFE7KbYEWH+FmFopnCFIlm7PdU=; b=po7guxZyGOQcfBjnb9LYEZzYozD7X5FFL/uZvipGHZg0l7L0m8HrSzHmVSp/D2UKjT 0AUoG4t4uRI0P7uv8LBOFGQQcmZ3jWM2nwNsZoXYd288mfyzy/Kv8Hc03IEA1AnaNars 6zRJX+MPpW0MWgWEcix0xqrpWr/kF2fmxFGnpGd0SVOotDl0cA3DfKjV9z4ZKvEQfavi BWge4rH1fqaofF/MrdcwG/nYtPlu5ylU1xBEP32K7GY/xZP7gkpdvx31VqLL1HzMyHmk WePxnFq9XG3r56q8YkIwJ6irlsGaZFTML4w6cAGhEc3PLZ0nicEyZqg8oK6d1YEKWtH7 u5LA== X-Gm-Message-State: AOAM5325udXzXTEzTNpX2PElxKB3RKrfid3mh0BkqMiDxFcZih2B12mC BzOQ4bHoIgBTE3qfYMIJjcRiYA== X-Google-Smtp-Source: ABdhPJxHZfOb9UMTvMfY0TOYnsyNy3pAynw8UhikG/kgqUZQDoSwCT+rqvbeUsQFKMN84pGDPsTDfQ== X-Received: by 2002:a05:620a:d85:b0:67b:a4:2036 with SMTP id q5-20020a05620a0d8500b0067b00a42036mr19369088qkl.112.1651155995814; Thu, 28 Apr 2022 07:26:35 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:d588]) by smtp.gmail.com with ESMTPSA id 21-20020ac85755000000b002f390bd8ac0sm84027qtx.53.2022.04.28.07.26.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Apr 2022 07:26:35 -0700 (PDT) Date: Thu, 28 Apr 2022 10:25:59 -0400 From: Johannes Weiner To: Minchan Kim 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 03:16:48PM -0700, Minchan Kim wrote: > On Wed, Apr 27, 2022 at 05:20:29PM -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. > > Thanks! Please consider ZSWPIN to rename more general term, too. That doesn't make sense to me. Zram is a swap backend, its traffic is accounted in PSWPIN/OUT. Zswap is a writeback cache on top of the swap backend. It has pages entering, refaulting, and being written back to the swap backend (PSWPOUT). A zswpout and a zramout are different things. > > From 8e9e2d6490b7082c41743fbdb9ffd2db4e3ce962 Mon Sep 17 00:00:00 2001 > > From: Johannes Weiner > > Date: Wed, 27 Apr 2022 17:15:15 -0400 > > Subject: [PATCH] mm: zswap: add basic meminfo and vmstat coverage fix fix > > > > Signed-off-by: Johannes Weiner Just for completeness, Nacked-by: Johannes Weiner > > @@ -87,7 +87,7 @@ 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", > > + seq_printf(m, "Compressed: %8lu kB\n", > > (unsigned long)(zswap_pool_total_size >> 10)); > > seq_printf(m, "Zswapped: %8lu kB\n", > > (unsigned long)atomic_read(&zswap_stored_pages) << > > -- > > 2.35.3 > >