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=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 91520C433E1 for ; Thu, 27 Aug 2020 17:52:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58175207CD for ; Thu, 27 Aug 2020 17:52:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="EAAmWl8C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726826AbgH0RwV (ORCPT ); Thu, 27 Aug 2020 13:52:21 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:49822 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbgH0RwU (ORCPT ); Thu, 27 Aug 2020 13:52:20 -0400 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 07RHos2s021672 for ; Thu, 27 Aug 2020 10:52:19 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=t0u1GdS/GsDLLXOwIOkkJ5krxovYtPBEXfJM9OWBdus=; b=EAAmWl8CFRNeBxb/vm8dscjZ6A+3HX3FxAB08KXrXDccC2vlxMAP7tc31Ww0D7D7przJ 0r7mpgscIpIeuCTVdJyTsGJ/zvL1HaFCSPPHPRUHdBiylUBuTc2ca2CctScdmrJWDpfb oyYMd26MmC2/S3xXrtgQEEZDo59HHauCK0s= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 335up66kmh-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 27 Aug 2020 10:52:19 -0700 Received: from intmgw002.06.prn3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::d) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Thu, 27 Aug 2020 10:52:18 -0700 Received: by devvm1096.prn0.facebook.com (Postfix, from userid 111017) id 32FE23922485; Thu, 27 Aug 2020 10:52:16 -0700 (PDT) Smtp-Origin-Hostprefix: devvm From: Roman Gushchin Smtp-Origin-Hostname: devvm1096.prn0.facebook.com To: CC: Andrew Morton , =Shakeel Butt , Johannes Weiner , Michal Hocko , , , Roman Gushchin Smtp-Origin-Cluster: prn0c01 Subject: [PATCH RFC 2/4] mm: kmem: remove redundant checks from get_obj_cgroup_from_current() Date: Thu, 27 Aug 2020 10:52:13 -0700 Message-ID: <20200827175215.319780-3-guro@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200827175215.319780-1-guro@fb.com> References: <20200827175215.319780-1-guro@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-08-27_10:2020-08-27,2020-08-27 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 priorityscore=1501 mlxlogscore=621 malwarescore=0 spamscore=0 clxscore=1015 impostorscore=0 suspectscore=1 phishscore=0 bulkscore=0 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008270134 X-FB-Internal: deliver Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are checks for current->mm and current->active_memcg in get_obj_cgroup_from_current(), but these checks are redundant: memcg_kmem_bypass() called just above performs same checks. Signed-off-by: Roman Gushchin --- mm/memcontrol.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9c08d8d14bc0..5d847257a639 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2919,9 +2919,6 @@ __always_inline struct obj_cgroup *get_obj_cgroup_f= rom_current(void) if (memcg_kmem_bypass()) return NULL; =20 - if (unlikely(!current->mm && !current->active_memcg)) - return NULL; - rcu_read_lock(); if (unlikely(current->active_memcg)) memcg =3D rcu_dereference(current->active_memcg); --=20 2.26.2