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Wed, 6 Mar 2024 09:01:20 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 456425F478; Wed, 6 Mar 2024 08:55:44 +0000 (UTC) X-Original-To: linux-ext4@vger.kernel.org Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0AE1160B97; Wed, 6 Mar 2024 08:55:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.125.252.92 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709715344; cv=none; b=nHxe8/pDCuFyIoRdl8DFePw6cjg4RWyhDE2RkzN35ZltWerXOfkMx9xrm4MWZRTtmMm/JyE5JNaSqvTb+6CRsVQCjdQv2elZk7bTYgueG005SMio1bViddJ8c+pi3dhRty9auWTY/MZPijJxcDdcPy8zO6DVutV/71FJ0YfaGdk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709715344; c=relaxed/simple; bh=32dhqEgXIybDFaJN1JuIlSUqelCcRZP5tULcFTO0inM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=P0VS1QNQdTGDu2AQ9UxS6YVs38CdVfE/gzrdkp3mJhNthnaExSZoMied92BNKn1XzYy+hnGY6/BVQPvKcJeUA4VcPbh+t2/82O8iyCCK1uimNM9BZwOTA+K4d5H4xS/Il3BUcUxlWplGvUIgoZEl8pj4Q3ByLzFwaKpQ/UGt2b4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com; spf=pass smtp.mailfrom=sk.com; arc=none smtp.client-ip=166.125.252.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sk.com X-AuditID: a67dfc5b-d85ff70000001748-08-65e82f7e84b4 From: Byungchul Park To: linux-kernel@vger.kernel.org Cc: kernel_team@skhynix.com, torvalds@linux-foundation.org, damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, gregkh@linuxfoundation.org, kernel-team@lge.com, linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, sj@kernel.org, jglisse@redhat.com, dennis@kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org, josef@toxicpanda.com, linux-fsdevel@vger.kernel.org, jack@suse.cz, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com, 42.hyeyoo@gmail.com, chris.p.wilson@intel.com, gwan-gyeong.mun@intel.com, max.byungchul.park@gmail.com, boqun.feng@gmail.com, longman@redhat.com, hdanton@sina.com, her0gyugyu@gmail.com Subject: [PATCH v13 14/27] cpu/hotplug: Use a weaker annotation in AP thread Date: Wed, 6 Mar 2024 17:55:00 +0900 Message-Id: <20240306085513.41482-15-byungchul@sk.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20240306085513.41482-1-byungchul@sk.com> References: <20240306085513.41482-1-byungchul@sk.com> X-Brightmail-Tracker: H4sIAAAAAAAAAzXSa0hTYRgH8N73XLdaHJbUSStjFIGRN7SeIKIPXU5XovsN6qSHtlKrWatF heWFMjUN5kolvLFETXNGdHGyFM1l2qplVmZqklpTw9pwadlW9OXhx3P5f3pYQllF+bOauBOS Nk6MUdFyUj44pWDR+ZB+KbSlay5kpYWC68clEvIqy2mwV5QhKL97AcNAwxp443YiGGt5ToDR YEdQ0P2BgLuNnQgsJRdpeNU7FRyuYRpshis0JBZV0vDi6ziGjuxrGMrMG6E5sxCD1dNHgnGA hlxjIvaWfgweUykDpoT50FOSw8B4dxjYOtsosLxbCDdudtBQY7GR0Hi/B8Orh3k0dJZPUNDc 2ESCPSudgttDhTR8dZsIMLmGGXhpzcdwJ8kblPL9NwVP0q0YUoqrMDjePkJQe6kLg7m8jYZ6 lxNDtdlAwM9bDQh6MgYZSE7zMJB7IQPBleRsEpI6ImFsNI9esVSodw4TQlL1KcHizieFp4W8 8CDnAyMk1b5jhHzzSaG6JEgoqhnAQsGIixLMpZdpwTxyjRFSBx1YGGptZYSm62Ok0Osw4s3+ e+TLoqUYjU7Shiw/IFcXptnJYx9lp53ZBxPQBJOKZCzPRfAVn7/g/3bbfv3t09wCvr3dQ/js x83lq9M/Uz4TnFPOF7euTkUsO43bwDsMUT6S3Hy+3yL6qOAW81kp8/4FBvJld6x/Q2Te9tWh q7TPSi6Sb0ks8Fru3Rll+eau29S/g5n845J2MhMp8tGkUqTUxOliRU1MRLBaH6c5HRx1NNaM vI9kOje+9z4asW+tQxyLVFMUK2R9kpISdfH62DrEs4TKT3H2Z6+kVESL+jOS9uh+7ckYKb4O BbCkaoYi3H0qWskdEk9IRyTpmKT9P8WszD8BbXpYyanXhwRaB9v69ShAlJLnbXCsXBigu2cM j6xv8NsXGLv3cFVxxer3Ow6c28mHe1L9VLptkWfXve7Z4l472tT0jFxycPKAciLHM2t5Z3DG N491+rbtuyYyu4+XmQ1zQj6t0q/LOF5Uq64h13wMUs/mZgVaMxcrh27s/n3d5ukrUpHxajEs iNDGi38AaAC9E0QDAAA= X-Brightmail-Tracker: H4sIAAAAAAAAAzXSWUwTYRDAcb89vt1Wq5tK4gY0aiOaaORIxIxHjA9GV6Pog0fUqFTYQMNp CyieYKFB5BANRQG1HClXvQoPXgUCilYFERpEQRRSFcIKXkU5FKnGl8kvM8n/aVhSeYH2ZDVR saI2Sh2hwnJKHrhKv/Skb5/od69HBtnpfuD6nkpBwQ0LhpbrlQgs1UkE9D/cAC+HJQRjTc9J yM1pQVDY84aE6sZuBLay0xjanNPB4RrCYM85i0FffAPDi4FxArqM5wmotG6Bp+eKCKgb+UhB bj+G/Fw9MTn6CBgxVzBgTvSG3rI8BsZ7/MHe3U5Dw2U7DbbXS+DSlS4M9212Chpv9xLQdrcA Q7dlgoanjY8paMnOoOHaYBGGgWEzCWbXEAOtdSYCbiZP1gzfftPwKKOOAEPJLQIcr+4hqEl9 R4DV0o6hwSURUGXNIWG09CGC3sxPDKSkjzCQn5SJ4GyKkYLkrgAY+1mA164UGqQhUkiuOizY hk2U8KSIF+7kvWGE5JrXjGCyxglVZYuF4vv9hFD41UUL1oozWLB+Pc8IaZ8chDDY3MwIjy+O UYLTkUts89ojXx0iRmjiRa3vmiB5WFF6CxXzVnZEMh5MRBNMGpKxPLeMH7b/+mvMLeI7OkZI tz24eXxVxgfabZKT5HxJ8/o0xLIzuc28IyfYTYrz5vtsajcV3HI+27DgX3AuX3mz7m9ENrnO GszCbiu5AL5JX4jPIbkJTalAHpqo+Ei1JiLARxcelhClOeITHB1pRZOvYj4xnn0bfW/bUI84 FqmmKdbKPopKWh2vS4isRzxLqjwUx0edolIRok44KmqjD2jjIkRdPfJiKdUsxaZdYpCSC1XH iuGiGCNq/18JVuaZiGwpqafiomsnpq72VY22mmaEBjnLY0qqQ6h1pYGBnwt/13RurL9qNDRJ 4f769i7MHWtyOftnHzj1Q5M1tNf0LHraM7/ngYOxu/flfZ7fu/VQ8I7a9+LCjJWZBmPQBUmy LJrjc3ezbWeZPymVl9csK9EOPMArtvOKL0mdmfs7w67lqyhdmNp/ManVqf8AuIaq+yYDAAA= X-CFilter-Loop: Reflected Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: cb92173d1f0 ("locking/lockdep, cpu/hotplug: Annotate AP thread") was introduced to make lockdep_assert_cpus_held() work in AP thread. However, the annotation is too strong for that purpose. We don't have to use more than try lock annotation for that. rwsem_acquire() implies: 1. might be a waiter on contention of the lock. 2. enter to the critical section of the lock. All we need in here is to act 2, not 1. So trylock version of annotation is sufficient for that purpose. Now that dept partially relies on lockdep annotaions, dept interpets rwsem_acquire() as a potential wait and might report a deadlock by the wait. So replaced it with trylock version of annotation. Signed-off-by: Byungchul Park --- kernel/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index a86972a91991..b708989f789f 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -535,7 +535,7 @@ int lockdep_is_cpus_held(void) static void lockdep_acquire_cpus_lock(void) { - rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_); + rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 1, _THIS_IP_); } static void lockdep_release_cpus_lock(void)