Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755965Ab1C3OIA (ORCPT ); Wed, 30 Mar 2011 10:08:00 -0400 Received: from service87.mimecast.com ([94.185.240.25]:51932 "HELO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754838Ab1C3OH7 convert rfc822-to-8bit (ORCPT ); Wed, 30 Mar 2011 10:07:59 -0400 Subject: Re: kmemleak for MIPS From: Catalin Marinas To: Eric Dumazet Cc: Maxin John , Daniel Baluta , naveen yadav , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <1301491622.3283.46.camel@edumazet-laptop> References: <9bde694e1003020554p7c8ff3c2o4ae7cb5d501d1ab9@mail.gmail.com> <1300960540.32158.13.camel@e102109-lin.cambridge.arm.com> <1301395206.583.53.camel@e102109-lin.cambridge.arm.com> <1301399454.583.66.camel@e102109-lin.cambridge.arm.com>

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<1301485085.29074.61.camel@e102109-lin.cambridge.arm.com> <1301488032.3283.42.camel@edumazet-laptop> <1301491622.3283.46.camel@edumazet-laptop> Organization: ARM Limited Date: Wed, 30 Mar 2011 15:07:48 +0100 Message-ID: <1301494068.29074.94.camel@e102109-lin.cambridge.arm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 X-OriginalArrivalTime: 30 Mar 2011 14:07:50.0474 (UTC) FILETIME=[DAB912A0:01CBEEE3] X-MC-Unique: 111033015075307901 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2048 Lines: 54 On Wed, 2011-03-30 at 14:27 +0100, Eric Dumazet wrote: > Le mercredi 30 mars 2011 à 14:17 +0100, Maxin John a écrit : > > I have compiled the kernel with below given modification in .config > > > > CONFIG_CMDLINE="uhash_entries=256" > > > > After booting with the new kernel, the "kmemleak" no longer complains > > about the "udp_table_init". > > However it do report another possible leak :) > > > > debian-mips:~# cat /sys/kernel/debug/kmemleak > > unreferenced object 0x8f085000 (size 4096): > > comm "swapper", pid 1, jiffies 4294937670 (age 1043.280s) > > hex dump (first 32 bytes): > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > backtrace: > > [<801ac7a8>] __kmalloc+0x130/0x180 > > [<80532500>] flow_cache_cpu_prepare+0x50/0xa8 > > [<8052378c>] flow_cache_init_global+0x90/0x138 > > [<80100584>] do_one_initcall+0x174/0x1e0 > > [<8050c348>] kernel_init+0xe4/0x174 > > [<80103d4c>] kernel_thread_helper+0x10/0x18 > > debian-mips:~# > > Hmm, then MIPS kmemleak port might have a problem with percpu data ? > > fcp->hash_table = kzalloc_node(sz, GFP_KERNEL, cpu_to_node(cpu)); > > fcp is a per cpu "struct flow_cache_percpu" I can't figure out what it is. Kmemleak uses this block for scanning the percpu data: for_each_possible_cpu(i) scan_block(__per_cpu_start + per_cpu_offset(i), __per_cpu_end + per_cpu_offset(i), NULL, 1); The __per_cpu_* symbols seem to be correctly defined in the MIPS vmlinux.lds.S as it uses the PERCPU macro directly. Other chunks allocated via pcpu_mem_alloc() should be tracked by kmemleak and either reported as leaks or scanned (and not reporting subsequent blocks referred from the percpu memory). -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/