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smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=X5naKi5g; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=wvaAtq9g; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="X5naKi5g"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="wvaAtq9g" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1707751001; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=C0+9xXf1xmlpe5oi4tOOoKsJ9pZFh5ERW9flQIZRs88=; b=X5naKi5gLpvZkYPThLTAQgcrOgmy7YnG179d5g9Zp0omwvh7aQLVvP0+Rlpn18mGTFxMVS jb2OZM69peAkDCL3yF1jhi9jdM6PGkhHzdqiyNkma8rajbUwpx+HZjDXUlKVpumyENxaZ2 LPo4BLCgiNACH4nQjgU9UuW+MEmyXZH1whNpAhisf6WmczXagVYIkUzTeheK86QtZWf9U6 3XJjiQDuJAWk7KCjGTytUpoi1cc/0Ph1Fc7WGqbAhlZSwzb/k+buVyjqd2knVFJJqEtp9Y Fj381DdX3HHi1MwyJ1buO9ZUt/ECWBEkvtQedGK44DUkGfRizsz9fRj14/9l8Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1707751001; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=C0+9xXf1xmlpe5oi4tOOoKsJ9pZFh5ERW9flQIZRs88=; b=wvaAtq9gXWu+gOMPiuUPNIHogxDOFBTHTovmSRErtvucLMRbKc+sW6mcVW7KPtOAn9Jr0c FJrzz2lzCTOfMLBw== To: Byungchul Park Cc: linux-kernel@vger.kernel.org, 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, 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, viro@zeniv.linux.org.uk, 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: Re: [PATCH v11 14/26] locking/lockdep, cpu/hotplus: Use a weaker annotation in AP thread In-Reply-To: <20240130025836.GA49173@system.software.com> References: <20240124115938.80132-1-byungchul@sk.com> <20240124115938.80132-15-byungchul@sk.com> <87il3ggfz9.ffs@tglx> <20240130025836.GA49173@system.software.com> Date: Mon, 12 Feb 2024 16:16:41 +0100 Message-ID: <871q9hlnl2.ffs@tglx> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, Jan 30 2024 at 11:58, Byungchul Park wrote: > On Fri, Jan 26, 2024 at 06:30:02PM +0100, Thomas Gleixner wrote: >> On Wed, Jan 24 2024 at 20:59, Byungchul Park wrote: >> >> Why is lockdep in the subsystem prefix here? You are changing the CPU >> hotplug (not hotplus) code, right? >> >> > 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. >> >> This lacks a proper explanation why this is too strong. >> >> > Furthermore, now that Dept was introduced, false positive alarms was >> > reported by that. Replaced it with try lock annotation. >> >> I still have zero idea what this is about. > > 1. can track PG_locked that is a potential deadlock trigger. > > https://lore.kernel.org/lkml/1674268856-31807-1-git-send-email-byungchul.park@lge.com/ Sure, but that wants to be explicitely explained in the changelog and not with a link. 'Now that Dept was introduced ...' is not an explanation. Thanks, tglx