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[66.111.4.227]) by smtp.gmail.com with ESMTPSA id z30sm14973956qtc.15.2020.11.17.17.46.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Nov 2020 17:46:00 -0800 (PST) Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailauth.nyi.internal (Postfix) with ESMTP id 2975927C0054; Tue, 17 Nov 2020 20:46:00 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute5.internal (MEProxy); Tue, 17 Nov 2020 20:46:00 -0500 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedrudefgedgfeekucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpeeuohhquhhn ucfhvghnghcuoegsohhquhhnrdhfvghnghesghhmrghilhdrtghomheqnecuggftrfgrth htvghrnhepvdelieegudfggeevjefhjeevueevieetjeeikedvgfejfeduheefhffggedv geejnecukfhppedufedurddutdejrddugeejrdduvdeinecuvehluhhsthgvrhfuihiivg eptdenucfrrghrrghmpehmrghilhhfrhhomhepsghoqhhunhdomhgvshhmthhprghuthhh phgvrhhsohhnrghlihhthidqieelvdeghedtieegqddujeejkeehheehvddqsghoqhhunh drfhgvnhhgpeepghhmrghilhdrtghomhesfhhigihmvgdrnhgrmhgv X-ME-Proxy: Received: from localhost (unknown [131.107.147.126]) by mail.messagingengine.com (Postfix) with ESMTPA id 7B2313064AAA; Tue, 17 Nov 2020 20:45:57 -0500 (EST) Date: Wed, 18 Nov 2020 09:45:40 +0800 From: Boqun Feng To: Matthew Wilcox Cc: Byungchul Park , Steven Rostedt , Thomas Gleixner , Ingo Molnar , torvalds@linux-foundation.org, peterz@infradead.org, mingo@redhat.com, will@kernel.org, linux-kernel@vger.kernel.org, joel@joelfernandes.org, alexander.levin@microsoft.com, daniel.vetter@ffwll.ch, chris@chris-wilson.co.uk, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, david@fromorbit.com, amir73il@gmail.com, bfields@fieldses.org, gregkh@linuxfoundation.org, kernel-team@lge.com Subject: Re: [RFC] Are you good with Lockdep? Message-ID: <20201118014540.GA1278700@boqun-archlinux> References: <20201111050559.GA24438@X58A-UD3R> <20201111105441.GA78848@gmail.com> <20201111093609.1bd2b637@gandalf.local.home> <87d00jo55p.fsf@nanos.tec.linutronix.de> <20201112081030.GB14554@X58A-UD3R> <20201112092612.00a19239@gandalf.local.home> <20201112145251.GB17076@casper.infradead.org> <20201116085757.GB26078@X58A-UD3R> <20201116153729.GC29991@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201116153729.GC29991@casper.infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matthew, On Mon, Nov 16, 2020 at 03:37:29PM +0000, Matthew Wilcox wrote: [...] > > It's not just about lockdep for semaphores. Mutexes will spin if the > current owner is still running, so to convert an interrupt-released > semaphore to a mutex, we need a way to mark the mutex as being released Could you provide an example for the conversion from interrupt-released semaphore to a mutex? I'd like to see if we can improve lockdep to help on that case. Regards, Boqun > by the new owner. > > I really don't think you want to report subsequent lockdep splats.