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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 32545C04E84 for ; Fri, 17 May 2019 11:42:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0692020815 for ; Fri, 17 May 2019 11:42:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="ZeBCvFex" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728771AbfEQLm3 (ORCPT ); Fri, 17 May 2019 07:42:29 -0400 Received: from forwardcorp1o.mail.yandex.net ([95.108.205.193]:54098 "EHLO forwardcorp1o.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727727AbfEQLm2 (ORCPT ); Fri, 17 May 2019 07:42:28 -0400 Received: from mxbackcorp2j.mail.yandex.net (mxbackcorp2j.mail.yandex.net [IPv6:2a02:6b8:0:1619::119]) by forwardcorp1o.mail.yandex.net (Yandex) with ESMTP id 191932E14DD; Fri, 17 May 2019 14:42:25 +0300 (MSK) Received: from smtpcorp1p.mail.yandex.net (smtpcorp1p.mail.yandex.net [2a02:6b8:0:1472:2741:0:8b6:10]) by mxbackcorp2j.mail.yandex.net (nwsmtp/Yandex) with ESMTP id lBau1MQ6yC-gO0uNjAp; Fri, 17 May 2019 14:42:25 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1558093345; bh=DuAu62W6AZc9BLNWjfPvq/8pURNd6AGdCvHd+9yn0vQ=; h=In-Reply-To:Message-ID:From:Date:References:To:Subject:Cc; b=ZeBCvFexSzy4eK7HnXw2m4E5GbH4MqlmnqC7eg/bDjugORxk6Zg2cuAreDZwKKW84 IglY+I/SVtpVb4zGjn7fFOaVikA0ixgEa/Wpe87mU8GxVjh0oByXvhV2GNYkoND1GK U5BObTMXhRqdbNw1ddlNlHde7uX4NKFs+sTewuzc= Authentication-Results: mxbackcorp2j.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red.dhcp.yndx.net (dynamic-red.dhcp.yndx.net [2a02:6b8:0:40c:4cb8:ba55:7b16:beea]) by smtpcorp1p.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id rncTEwRDdX-gOdCPYWB; Fri, 17 May 2019 14:42:24 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Subject: Re: [PATCH RFC] proc/meminfo: add KernelMisc counter To: Roman Gushchin Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" References: <155792098821.1536.17069603544573830315.stgit@buzz> <20190516175912.GA32262@tower.DHCP.thefacebook.com> From: Konstantin Khlebnikov Message-ID: <6bb58fe4-d860-555e-3fb9-17b4ab552da6@yandex-team.ru> Date: Fri, 17 May 2019 14:42:24 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190516175912.GA32262@tower.DHCP.thefacebook.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-CA Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16.05.2019 20:59, Roman Gushchin wrote: > On Wed, May 15, 2019 at 02:49:48PM +0300, Konstantin Khlebnikov wrote: >> Some kernel memory allocations are not accounted anywhere. >> This adds easy-read counter for them by subtracting all tracked kinds. >> >> Signed-off-by: Konstantin Khlebnikov > > We have something similar in userspace, and it was very useful several times. > In our case, it was mostly vmallocs and percpu stuff (which are now shown > in meminfo), but for sure there are other memory users who are not. > > I don't particularly like the proposed name, but have no better ideas. > It's really a gray area, everything we know, it's that the memory is occupied > by something. > Probably it's better to add overall 'MemKernel'. Detailed analysis anyway requires special tools. >> --- >> Documentation/filesystems/proc.txt | 2 ++ >> fs/proc/meminfo.c | 41 +++++++++++++++++++++++++----------- >> 2 files changed, 30 insertions(+), 13 deletions(-) >> >> diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt >> index 66cad5c86171..f11ce167124c 100644 >> --- a/Documentation/filesystems/proc.txt >> +++ b/Documentation/filesystems/proc.txt >> @@ -891,6 +891,7 @@ VmallocTotal: 112216 kB >> VmallocUsed: 428 kB >> VmallocChunk: 111088 kB >> Percpu: 62080 kB >> +KernelMisc: 212856 kB >> HardwareCorrupted: 0 kB >> AnonHugePages: 49152 kB >> ShmemHugePages: 0 kB >> @@ -988,6 +989,7 @@ VmallocTotal: total size of vmalloc memory area >> VmallocChunk: largest contiguous block of vmalloc area which is free >> Percpu: Memory allocated to the percpu allocator used to back percpu >> allocations. This stat excludes the cost of metadata. >> + KernelMisc: All other kinds of kernel memory allocaitons > ^^^ > typo >> >> .............................................................................. >> >> diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c >> index 568d90e17c17..7bc14716fc5d 100644 >> --- a/fs/proc/meminfo.c >> +++ b/fs/proc/meminfo.c >> @@ -38,15 +38,21 @@ static int meminfo_proc_show(struct seq_file *m, void *v) >> long cached; >> long available; >> unsigned long pages[NR_LRU_LISTS]; >> - unsigned long sreclaimable, sunreclaim; >> + unsigned long sreclaimable, sunreclaim, misc_reclaimable; >> + unsigned long kernel_stack_kb, page_tables, percpu_pages; >> + unsigned long anon_pages, file_pages, swap_cached; >> + long kernel_misc; >> int lru; >> >> si_meminfo(&i); >> si_swapinfo(&i); >> committed = percpu_counter_read_positive(&vm_committed_as); >> >> - cached = global_node_page_state(NR_FILE_PAGES) - >> - total_swapcache_pages() - i.bufferram; >> + anon_pages = global_node_page_state(NR_ANON_MAPPED); >> + file_pages = global_node_page_state(NR_FILE_PAGES); >> + swap_cached = total_swapcache_pages(); >> + >> + cached = file_pages - swap_cached - i.bufferram; >> if (cached < 0) >> cached = 0; >> >> @@ -56,13 +62,25 @@ static int meminfo_proc_show(struct seq_file *m, void *v) >> available = si_mem_available(); >> sreclaimable = global_node_page_state(NR_SLAB_RECLAIMABLE); >> sunreclaim = global_node_page_state(NR_SLAB_UNRECLAIMABLE); >> + misc_reclaimable = global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE); >> + kernel_stack_kb = global_zone_page_state(NR_KERNEL_STACK_KB); >> + page_tables = global_zone_page_state(NR_PAGETABLE); >> + percpu_pages = pcpu_nr_pages(); >> + >> + /* all other kinds of kernel memory allocations */ >> + kernel_misc = i.totalram - i.freeram - anon_pages - file_pages >> + - sreclaimable - sunreclaim - misc_reclaimable >> + - (kernel_stack_kb >> (PAGE_SHIFT - 10)) >> + - page_tables - percpu_pages; >> + if (kernel_misc < 0) >> + kernel_misc = 0; > > Hm, why? Is there any realistic scenario (not caused by the kernel doing > the memory accounting wrong) when it's negative? > > Maybe it's better to show it as it is, if it's negative? Because > it might be a good indication that something's wrong with some of > the counters. Such kind of sanitisation is a common practice for racy counters. See 'cached' above. > > Thanks! >