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[66.111.4.227]) by smtp.gmail.com with ESMTPSA id 22-20020ac84e96000000b0034359fc348fsm6124120qtp.73.2022.09.16.10.46.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Sep 2022 10:46:30 -0700 (PDT) Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailauth.nyi.internal (Postfix) with ESMTP id 0719527C0061; Fri, 16 Sep 2022 13:46:29 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute2.internal (MEProxy); Fri, 16 Sep 2022 13:46:30 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedrfedvtddguddulecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpeffhffvvefukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpeeuohhq uhhnucfhvghnghcuoegsohhquhhnrdhfvghnghesghhmrghilhdrtghomheqnecuggftrf grthhtvghrnhephedugfduffffteeutddvheeuveelvdfhleelieevtdeguefhgeeuveei udffiedvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomh epsghoqhhunhdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqieelvdeghedt ieegqddujeejkeehheehvddqsghoqhhunhdrfhgvnhhgpeepghhmrghilhdrtghomhesfh higihmvgdrnhgrmhgv X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 16 Sep 2022 13:46:27 -0400 (EDT) Date: Fri, 16 Sep 2022 10:46:18 -0700 From: Boqun Feng To: Waiman Long Cc: Tetsuo Handa , Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner , Shaokun Zhang , Sebastian Andrzej Siewior , Petr Mladek , Andrew Morton , Ben Dooks , Rasmus Villemoes , Luis Chamberlain , Xiaoming Ni , John Ogness , LKML Subject: Re: [PATCH (repost)] locking/lockdep: add debug_show_all_lock_holders() Message-ID: References: <3e027453-fda4-3891-3ec3-5623f1525e56@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3e027453-fda4-3891-3ec3-5623f1525e56@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 16, 2022 at 10:51:14AM -0400, Waiman Long wrote: [...] > > > > I'm expecting lockdep to continue working without calling printk() even after > > one of problem patterns (e.g. circular locking dependency) was printk()ed, so that > > debug_show_all_locks()/debug_show_all_lock_holders() can call printk() when needed. > > > > Changing debug_locks behavior is a future patch. For now, this patch alone > > will help debugging Greg's usb.git#usb-testing tree which is generating > > many "INFO: task hung in" reports. The default behavior today does make sense: if the system has one deadlock it should be fixed first before searching out another. So I expect that changing debug_locks behavior would be configurable and we keep the default as today. > > Boqun is actually working on a modularization patch to make some lockdep > checking still active even after a lockdep bug is reported. I think he will > take into consideration about this request. > Yes, this is one of the "problems" I try to resolve while cleaning up the lockdep. Regards, Boqun > Cheers, > Longman >