From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751881AbcFFL00 (ORCPT ); Mon, 6 Jun 2016 07:26:26 -0400 Received: from foss.arm.com ([217.140.101.70]:35724 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751297AbcFFL0Z (ORCPT ); Mon, 6 Jun 2016 07:26:25 -0400 Date: Mon, 6 Jun 2016 12:26:20 +0100 From: Catalin Marinas To: Christoph Hellwig Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Jens Axboe Subject: kmemleak report after 9082e87bfbf8 ("block: remove struct bio_batch") Message-ID: <20160606112620.GA29910@e104818-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, I tried enabling kmemleak on 4.7-rc2 on an x86 host (macbook pro running Debian sid) and I get some kmemleak reports every few minutes coming from the block layer. Reverting commit 9082e87bfbf8 ("block: remove struct bio_batch") makes them go away: unreferenced object 0xffff880077859c00 (size 256): comm "upowerd", pid 1185, jiffies 4295046823 (age 1874.852s) hex dump (first 32 bytes): 80 39 08 00 00 ea ff ff 00 10 00 00 00 00 00 00 .9.............. 00 00 00 00 00 00 00 00 00 e4 21 49 02 88 ff ff ..........!I.... backtrace: [] kmem_cache_alloc+0xfe/0x250 [] bvec_alloc+0x57/0xe0 [] bio_alloc_bioset+0x16f/0x240 [] next_bio+0x1f/0x50 [] blkdev_issue_zeroout+0xea/0x1d0 [] ext4_issue_zeroout+0x40/0x50 [ext4] [] ext4_ext_map_blocks+0x144d/0x1bb0 [ext4] [] release_pages+0x254/0x310 [] __pagevec_release+0x2a/0x40 [] mpage_prepare_extent_to_map+0x227/0x2c0 [ext4] [] ext4_map_blocks+0x173/0x5d0 [ext4] [] ext4_writepages+0x700/0xd40 [ext4] [] legitimize_mnt+0xe/0x50 [] kmem_cache_alloc+0xfe/0x250 [] __filemap_fdatawrite_range+0xc5/0x100 [] filemap_write_and_wait_range+0x33/0x70 It's coming from various processes, not just upowerd. I haven't got the chance to dig further but you may have a better idea. Thanks. -- Catalin