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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 96D33C43612 for ; Wed, 9 Jan 2019 14:10:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F994206BB for ; Wed, 9 Jan 2019 14:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731179AbfAIOJ7 (ORCPT ); Wed, 9 Jan 2019 09:09:59 -0500 Received: from shelob.surriel.com ([96.67.55.147]:40932 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729994AbfAIOJ7 (ORCPT ); Wed, 9 Jan 2019 09:09:59 -0500 Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1ghEYI-0000vK-BT; Wed, 09 Jan 2019 09:09:50 -0500 Message-ID: Subject: Re: [PATCH] mm,slab,memcg: call memcg kmem put cache with same condition as get From: Rik van Riel To: Shakeel Butt Cc: LKML , kernel-team@fb.com, Linux MM , stable@vger.kernel.org, Alexey Dobriyan , Christoph Lameter , Pekka Enberg , Andrew Morton , David Rientjes , Joonsoo Kim , Johannes Weiner , Tejun Heo Date: Wed, 09 Jan 2019 09:09:49 -0500 In-Reply-To: References: <20190109040107.4110-1-riel@surriel.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-BjQKRT72GxnNzF5sMK37" X-Mailer: Evolution 3.28.5 (3.28.5-1.fc28) Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-BjQKRT72GxnNzF5sMK37 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2019-01-08 at 21:36 -0800, Shakeel Butt wrote: > On Tue, Jan 8, 2019 at 8:01 PM Rik van Riel wrote: > >=20 > > There is an imbalance between when slab_pre_alloc_hook calls > > memcg_kmem_get_cache and when slab_post_alloc_hook calls > > memcg_kmem_put_cache. > >=20 >=20 > Can you explain how there is an imbalance? If the returned kmem cache > from memcg_kmem_get_cache() is the memcg kmem cache then the refcnt > of > memcg is elevated and the memcg_kmem_put_cache() will correctly > decrement the refcnt of the memcg. Indeed, you are right. Never mind this patch. Back to square one on that bug. --=20 All Rights Reversed. --=-BjQKRT72GxnNzF5sMK37 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAlw2AK4ACgkQznnekoTE 3oNwFQgAobJ9soQwmXZZ20jPst6Vl7FQSysrv9t4VZcbUewwW6/5ZRB2anQinVnE Gibkl56x1s2oZUBsrc4/Uj31f3Q4RB22cmMzHQTA2Yj2rQgcrg6bgLvFaNuQ3naN ws1l31twrEQ8tAK7ev1J0jIrOX4zVGAc31UF+7KqQaVjm5BQB1wTlgjbJjgGOuyJ iRuMJHC6FVyy3jEFM3QagSwx5fm5/zLgmfSecELHbfr1CLrRAZ8ZVfpxKDx8N4cw eZ3wpjCwoaxjNWbAv4RdP8TDTyYQ539hwqQe7qhNpnd62p3V3fBKFJTv7SiPjVo/ x9W2kutLBLvyrjNoiGlSzJf0xTjj9Q== =+tvN -----END PGP SIGNATURE----- --=-BjQKRT72GxnNzF5sMK37--