From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Date: Sat, 10 Feb 2018 17:42:57 +0000 Subject: Re: Software evolution around =?UTF-8?Q?=E2=80=9Ccheckpatch=2Epl=E2=80=9D=3F?= Message-Id: <1518284577.16865.8.camel@perches.com> List-Id: References: <0406765c-bdd1-1a82-cf66-1c248063ae4f@users.sourceforge.net> <20180204112346.0977e938@archlinux> <9420fc82-1a37-3601-bafe-f57ef953bfcd@users.sourceforge.net> <87DF341A-1356-4B1B-8D25-14D5B0AAB01D@jic23.retrosnub.co.uk> <20180210145336.233c721d@archlinux> <1518274783.6579.2.camel@perches.com> <20180210155734.708d01b6@archlinux> In-Reply-To: <20180210155734.708d01b6@archlinux> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Jonathan Cameron Cc: SF Markus Elfring , linux-iio@vger.kernel.org, linux-input@vger.kernel.org, Jonathan Cameron , Hartmut Knaack , Jiri Kosina , Lars-Peter Clausen , Peter Meerwald-Stadler , Srinivas Pandruvada , LKML , kernel-janitors@vger.kernel.org On Sat, 2018-02-10 at 15:57 +0000, Jonathan Cameron wrote: > On Sat, 10 Feb 2018 06:59:43 -0800 > Joe Perches wrote: > > > On Sat, 2018-02-10 at 14:53 +0000, Jonathan Cameron wrote: > > > While it would be great to improve checkpatches false > > > positive rate, it's very nature as a string matcher makes > > > this hard. > > > > true. > > > > what are the false positives you see? > > > > This particular case is only 'sort of' a false positive > in the warning that a message printed on a memory allocation > failure 'may' not add any information over the generic case. Right. So it's not a 'false positive' at all. Are there any actual 'false positives' you know of? > Very hard to judge on whether it is useful to know more than > an allocation failed somewhere or not. > > Message makes this clear: > > “WARNING: Possible unnecessary 'out of memory' message” > > (from the script “checkpatch.pl”) > > We also have the balance between any changes to existing code > adding 'some' maintenance overhead vs changing this stuff > in a new driver - which is what checkpatch is really intended > for. There's almost zero maintenance overhead here. The time it takes for the back and forth replies is likely larger. > So I think checkpatch is striking the right balance here in > how it warns. Obviously if it could assess the text > and come to an informed decision that would be great but > we are some way from that ;) The 'informed' bit is difficult as it is mostly a political problem. This particular message really is unnecessary as the generic dump_stack on any normal allocation (ie: without __GFP_WARN) already emits location specific information. Removing these messages can help make the kernel image smaller and thereby help make these OOM messages a tiny bit less likely. I just wish Markus would improve his consistently terrible commit messages that just restate the action being done and detail _why_ a particular thing _should_ be done. His acceptance rate would improve as many of these back and forth replies for what trivialities he posts as patches would be minimized.