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Fri, 23 Sep 2022 02:20:59 +0000 Received: from DM6PR12MB4140.namprd12.prod.outlook.com ([fe80::e0c5:bb15:a743:7ddb]) by DM6PR12MB4140.namprd12.prod.outlook.com ([fe80::e0c5:bb15:a743:7ddb%3]) with mapi id 15.20.5654.020; Fri, 23 Sep 2022 02:20:59 +0000 Message-ID: <60fa5b16-021e-1e54-7e06-39bbb871eaef@nvidia.com> Date: Thu, 22 Sep 2022 19:20:56 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH v1 3/3] checkpatch: warn on usage of VM_BUG_ON() and other BUG variants Content-Language: en-US To: Joe Perches , David Hildenbrand , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Linus Torvalds , Andrew Morton , Ingo Molnar , David Laight , Jonathan Corbet , Andy Whitcroft , Dwaipayan Ray , Lukas Bulwahn , Baoquan He , Vivek Goyal , Dave Young , Jani Nikula , Michael Ellerman , Nicholas Piggin , Christophe Leroy References: <20220920122302.99195-1-david@redhat.com> <20220920122302.99195-4-david@redhat.com> <3179f4545d3f71358da3e6c6ee18085af601b2eb.camel@perches.com> From: John Hubbard In-Reply-To: <3179f4545d3f71358da3e6c6ee18085af601b2eb.camel@perches.com> Content-Type: text/plain; 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b=q6o6FlD8UbvwFZ35dbjNj+8Epn908YeplGE/Bl6qdKHT99WgZavb+8+pTDxx1dGMj1KCE5 bW3agiwf89bqhgxSfnGu0thrm7u4wU3xOAWYPC7PU4xh0SadlGBp1OZyttAGm0Y7K3CPl9 EEb2J46SX4Z9YdzLr0zKGPrPGfe5bds= Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=DHqAZ4CP; spf=pass (imf15.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.244.45 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") X-Rspam-User: X-Stat-Signature: 3irha3nqwhoet45sn68cqw566bjto4w4 X-Rspamd-Queue-Id: 4F9C4A0009 X-Rspamd-Server: rspam02 X-HE-Tag: 1663899664-833340 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: On 9/22/22 19:11, Joe Perches wrote: >> Should this be a separate patch? Adding a bunch of exceptions to the BUG() rules is >> a separate and distinct thing from adding VM_BUG_ON() and other *BUG*() variants to >> the mix. > > Not in my opinion. OK, then. :) > >>> my $msg_level = \&WARN; >>> $msg_level = \&CHK if ($file); >>> &{$msg_level}("AVOID_BUG", >>> - "Avoid crashing the kernel - try using WARN_ON & recovery code rather than BUG() or BUG_ON()\n" . $herecurr); >>> + "Do not crash the kernel unless it is unavoidable - use WARN_ON_ONCE & recovery code (if reasonable) rather than BUG() or variants.\n" . $herecurr); >> >> Here's a requested tweak, to clean up the output and fix punctuation: >> >> "Avoid crashing the kernel--use WARN_ON_ONCE() plus recovery code (if feasible) instead of BUG() or variants.\n" . $herecurr); > > Fixing punctuation here would be removing the trailing period as checkpatch > only has periods for multi-sentence output messages. OK, let's do that too. > > And I think that "Do not crash" is a stronger statement than "Avoid crashing" > so I prefer the original suggestion but it's not a big deal either way. Yes, stronger wording is better. So how about this: "Do not crash the kernel unless it is absolutely unavoidable--use WARN_ON_ONCE() plus recovery code (if feasible) instead of BUG() or variants\n" . $herecurr); thanks, -- John Hubbard NVIDIA