Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751185AbdFCC3F (ORCPT ); Fri, 2 Jun 2017 22:29:05 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:33737 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751141AbdFCC3E (ORCPT ); Fri, 2 Jun 2017 22:29:04 -0400 Date: Sat, 3 Jun 2017 10:28:58 +0800 From: Wei Yang To: zhong jiang Cc: Wei Yang , akpm@linux-foundation.org, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/vmalloc: a slight change of compare target in __insert_vmap_area() Message-ID: <20170603022858.GB11080@WeideMacBook-Pro.local> Reply-To: Wei Yang References: <20170524100347.8131-1-richard.weiyang@gmail.com> <592649CC.8090702@huawei.com> <20170526013639.GA10727@WeideMacBook-Pro.local> <59278B13.4070304@huawei.com> <20170602014549.GA10347@WeideMBP.lan> <5930CCBE.4030802@huawei.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="pvezYHf7grwyp3Bc" Content-Disposition: inline In-Reply-To: <5930CCBE.4030802@huawei.com> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3213 Lines: 94 --pvezYHf7grwyp3Bc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jun 02, 2017 at 10:26:06AM +0800, zhong jiang wrote: >On 2017/6/2 9:45, Wei Yang wrote: >> On Fri, May 26, 2017 at 09:55:31AM +0800, zhong jiang wrote: >>> On 2017/5/26 9:36, Wei Yang wrote: >>>> On Thu, May 25, 2017 at 11:04:44AM +0800, zhong jiang wrote: >>>>> I hit the overlap issue, but it is hard to reproduced. if you think = it is safe. and the situation >>>>> is not happen. AFAIC, it is no need to add the code. >>>>> >>>>> if you insist on the point. Maybe VM_WARN_ON is a choice. >>>>> >>>> Do you have some log to show the overlap happens? >>> Hi wei >>> >>> cat /proc/vmallocinfo >>> 0xf1580000-0xf1600000 524288 raw_dump_mem_write+0x10c/0x188 phys=3D8b9= 01000 ioremap >>> 0xf1638000-0xf163a000 8192 mcss_pou_queue_init+0xa0/0x13c [mcss] phy= s=3Dfc614000 ioremap >>> 0xf528e000-0xf5292000 16384 n_tty_open+0x10/0xd0 pages=3D3 vmalloc >>> 0xf5000000-0xf9001000 67112960 devm_ioremap+0x38/0x70 phys=3D40000000 i= oremap >> These two ranges overlap. >> >> This is hard to say where is the problem. From the code point of view, I= don't >> see there is possibility to allocate an overlapped range. >> >> Which version of your kernel? >> Hard to reproduce means just see once?=20 > yes, just once. I have also no see any problem from the code. The ker= nel version is linux 4.1. > but That indeed exist.=20 > This is really interesting. While without reproducing the behavior, it is really costly to debug in the code. I took a look into my own /proc/vmallocinfo, there are around hundred entri= es. Currently, I don't have a clue to dive into the issue. > Thanks >zhongjiang >>> 0xfe001000-0xfe002000 4096 iotable_init+0x0/0xc phys=3D20001000 iore= map >>> 0xfe200000-0xfe201000 4096 iotable_init+0x0/0xc phys=3D1a000000 iore= map >>> 0xff100000-0xff101000 4096 iotable_init+0x0/0xc phys=3D2000a000 iore= map >>> >>> I hit the above issue, but the log no more useful info. it just is foun= d by accident. >>> and it is hard to reprodeced. no more info can be supported for further= investigation. >>> therefore, it is no idea for me.=20 >>> >>> Thanks >>> zhongjinag >>> > --=20 Wei Yang Help you, Help me --pvezYHf7grwyp3Bc Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJZMh7qAAoJEKcLNpZP5cTdYZ0P/RTqqD0VGv88wZBuRuXMoqVO nH2bFA9ITSesXvDGYnFVWlno9UZzHhz/4F04E6dyj8ivXOYMyIzC1A81iaKqXhE5 OZZzj5+D7j0ARyNd7n1gQKypGUVaNJDHw4vcM3YWghsUn+t4gcLC1c5iJ8+EXoF5 36CZHQoFOq8hvw2UYvl/Ois0BtWtyCC3rqwWc1RXvuScZ/i4bpY1XdqwReb37swP PLea/DpnLGxgb/eRryC38WaeVs7VlwzzYk9L4/kFvJQ95zVdEsiEt+InVuAjfQNW z9CzuU0QtVqJ1HPrCfakEmpqeUF8u0EEfPAMQVebEDOLmUSLAI8eod/kDcbXqUML HqtOTT5+t/BsFth04vPApHGeyz8q9eFxd43D6W64nlD79+EpuKiBgrsY4cwiZeRI s/ZWrrrUPa6Fh/BlEgnoLNsk3i/Nmb9AdxwOfYbyKhTZj+1zHJd0I+d7HPuFXhuU vyi1M3YN3+dlycmu2YwxIluKiIMoX+LtdUnVilh1U7fkQO3mlbVY2PPrxm4FqEqy QpxKbpPLV6L+TK2q9hNZEnj9VRxBNcrUG1Ejx9RuWMaMSx7Pngh8ZL3WOHpKal/P up6+ifK3XySe7HWqIHfeIUd9kAskqgyIQFY35DGu5l7GkkRP3eykZl/m9WCiGpZG k5TBFKzoSM/2UTvVAQ1L =pXHc -----END PGP SIGNATURE----- --pvezYHf7grwyp3Bc--