From patchwork Mon Apr 13 01:09:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gregory Fong X-Patchwork-Id: 6204291 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 46247BF4A6 for ; Mon, 13 Apr 2015 01:12:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3EEA420295 for ; Mon, 13 Apr 2015 01:12:41 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4127420274 for ; Mon, 13 Apr 2015 01:12:40 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YhSsg-0006Nh-RM; Mon, 13 Apr 2015 01:09:42 +0000 Received: from mail-pa0-x236.google.com ([2607:f8b0:400e:c03::236]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YhSsd-0006LB-Od for linux-arm-kernel@lists.infradead.org; Mon, 13 Apr 2015 01:09:40 +0000 Received: by paboj16 with SMTP id oj16so85221115pab.0 for ; Sun, 12 Apr 2015 18:09:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=kXaXgisy2awTF/WBs1Ahmy5Hi9RzRwMg3VOOmkcE/Ys=; b=SMhMqDwI2qBo/tNLPh1hvKYWU0i5O+Nn+dHf13vYn4tFx9m4/nC3XjUuW6jyoA+cuM RcwvcNIM5zfAIk9nVDRhNHWZsODLxSnLA8WdHbMm94Ea0zXnM8WRpBDp/PReCuZklj6t ZaTv+F1Zdw0IyjcgFIqg4satiYwj/iLreDXwVMarAI2N7TECYvXn7lGkrm72SOXvUddJ +Bs9jzurNGt3YcYONLMhXQn3V126Yv0Fb0duR4h535AViAFdAbxuzyNuLsSu9YHIvEI3 YhdmPkkULWQVja4g0rP+Tpg/Jn9Km+nwASXUYN/rAkMqs7M6rz3eJ6KqoJ9FPSs4Farm URAQ== X-Received: by 10.66.63.7 with SMTP id c7mr22303994pas.13.1428887357306; Sun, 12 Apr 2015 18:09:17 -0700 (PDT) Received: from corellia.local (cpe-98-148-132-5.socal.res.rr.com. [98.148.132.5]) by mx.google.com with ESMTPSA id qp13sm5401172pdb.31.2015.04.12.18.09.15 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Sun, 12 Apr 2015 18:09:16 -0700 (PDT) Date: Sun, 12 Apr 2015 18:09:13 -0700 From: Gregory Fong To: Russell King - ARM Linux Subject: Re: [PATCH] ARM: print cma-reserved pages from show_mem Message-ID: <20150413010913.GA15225@corellia.local> References: <54D534FB.1090101@codeaurora.org> <20150210113230.GJ8656@n2100.arm.linux.org.uk> <20150326114612.GD8656@n2100.arm.linux.org.uk> <20150326123028.GM4701@suse.de> <35FD53F367049845BC99AC72306C23D104A310D42397@CNBJMBX05.corpusers.net> <20150410112430.GB12732@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20150410112430.GB12732@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150412_180939_868424_C65465E1 X-CRM114-Status: GOOD ( 21.29 ) X-Spam-Score: -0.6 (/) Cc: Florian Fainelli , Laura Abbott , "Wang, Yalin" , Nicolas Pitre , Catalin Marinas , "vishnu.ps@samsung.com" , open list , Mel Gorman , Johannes Weiner , Marek Szyprowski , "linux-arm-kernel@lists.infradead.org" , Kees Cook X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Fri, Apr 10, 2015 at 12:24:31PM +0100, Russell King - ARM Linux wrote: > On Fri, Apr 10, 2015 at 01:18:04PM +0800, Wang, Yalin wrote: > > > [ 12.212102] active_anon:734 inactive_anon:1189 isolated_anon:0 > > > [ 12.212102] active_file:0 inactive_file:0 isolated_file:0 > > > [ 12.212102] unevictable:0 dirty:0 writeback:0 unstable:0 > > > [ 12.212102] free:254104 slab_reclaimable:82 slab_unreclaimable:843 > > Here, we have 82 pages reclaimable, which is 328kB, and 843 unreclaimable > which is 3372kB, which is a total of 925 pages. > > > > [ 12.212102] mapped:429 shmem:1815 pagetables:13 bounce:0 > > > [ 12.212102] free_cma:4032 > > > [ 12.243172] DMA free:754080kB min:3472kB low:4340kB high:5208kB > > > active_anon:180kB inactive_anon:0kB active_file:0kB inactive_file:0kB > > > unevictable:0kB isolated(anon):0kB isolated(file):0kB present:778240kB > > > managed:759252kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB > > > shmem:0kB slab_reclaimable:328kB slab_unreclaimable:3372kB > > Which agrees here. > > > > [ 12.401609] 834 slab pages > > but not here... this is an interesting difference, because in the ARM > version of show_mem(), we count the actual number of pages where > PageSlab() returns true. Can slab pages also be reserved pages or > swap cache pages? I thought they were exclusive of those. So, the > question comes... why the difference in accounting, and which one is > correct. > > Maybe there's a bug in the accounting somewhere... Yes, the ARM show_mem wasn't updated after the various allocators (SLUB, SLAB, SLOB) were updated to use compound pages. Fixing it, you get [ 7.081826] sysrq: SysRq : Show Memory [ 7.085610] Mem-info: [ 7.087890] DMA per-cpu: [ 7.090431] CPU 0: hi: 186, btch: 31 usd: 98 [ 7.095230] HighMem per-cpu: [ 7.098116] CPU 0: hi: 90, btch: 15 usd: 29 [ 7.102923] active_anon:724 inactive_anon:1189 isolated_anon:0 [ 7.102923] active_file:0 inactive_file:0 isolated_file:0 [ 7.102923] unevictable:0 dirty:0 writeback:0 unstable:0 [ 7.102923] free:253980 slab_reclaimable:83 slab_unreclaimable:846 [ 7.102923] mapped:429 shmem:1815 pagetables:15 bounce:0 [ 7.102923] free_cma:4032 [ 7.133995] DMA free:753344kB min:3472kB low:4340kB high:5208kB active_anon:292kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:778240kB managed:759188kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:332kB slab_unreclaimable:3384kB kernel_stack:256kB pagetables:36kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes [ 7.174080] lowmem_reserve[]: 0 0 264 264 [ 7.178175] HighMem free:262576kB min:264kB low:572kB high:884kB active_anon:2604kB inactive_anon:4756kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:270336kB managed:270336kB mlocked:0kB dirty:0kB writeback:0kB mapped:1716kB shmem:7260kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:24kB unstable:0kB bounce:0kB free_cma:16128kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes [ 7.218955] lowmem_reserve[]: 0 0 0 0 [ 7.222687] DMA: 8*4kB (UEM) 8*8kB (UM) 4*16kB (UEM) 5*32kB (UM) 2*64kB (M) 4*128kB (UEM) 3*256kB (M) 2*512kB (EM) 5*1024kB (UEM) 6*2048kB (UEM) 3*4096kB (EM) 88*8192kB (MR) = 753344kB [ 7.239477] HighMem: 0*4kB 0*8kB 1*16kB (M) 1*32kB (M) 2*64kB (UM) 2*128kB (UM) 2*256kB (UC) 3*512kB (UMC) 2*1024kB (UC) 2*2048kB (UC) 2*4096kB (UC) 30*8192kB (MRC) = 262576kB [ 7.255455] 1815 total pagecache pages [ 7.259211] 0 pages in swap cache [ 7.262533] Swap cache stats: add 0, delete 0, find 0/0 [ 7.267764] Free swap = 0kB [ 7.270647] Total swap = 0kB [ 7.282890] 262144 pages of RAM [ 7.286041] 254274 free pages [ 7.289013] 4763 reserved pages [ 7.292157] 929 slab pages [ 7.294868] 1063 pages shared [ 7.297839] 0 pages swap cached And now we see 83 slab_reclaimable + 846 slab_unreclaimable adds up correctly to the total of 929. The patch below will end up with the correct count. 8<=== diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 1609b02..8d606bb 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -117,7 +117,7 @@ void show_mem(unsigned int filter) else if (PageSwapCache(page)) cached++; else if (PageSlab(page)) - slab++; + slab += 1 << compound_order(page); else if (!page_count(page)) free++; else