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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::c) 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 10:52:17 -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 adultscore=0 clxscore=1015 suspectscore=1 bulkscore=0 malwarescore=0 impostorscore=0 mlxlogscore=614 lowpriorityscore=0 phishscore=0 mlxscore=0 spamscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008270134 X-FB-Internal: deliver X-Rspamd-Queue-Id: 6B74810097AA0 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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