From: "Fabio M. De Francesco" <email@example.com> To: Suren Baghdasaryan <firstname.lastname@example.org> Cc: "Greg Kroah-Hartman" <email@example.com>, "Arve Hjønnevåg" <firstname.lastname@example.org>, "Todd Kjos" <email@example.com>, "Martijn Coenen" <firstname.lastname@example.org>, "Joel Fernandes" <email@example.com>, "Christian Brauner" <firstname.lastname@example.org>, "Hridya Valsaraju" <email@example.com>, LKML <firstname.lastname@example.org>, email@example.com Subject: Re: [PATCH] staging: android: Remove set but unused variable in ashmem.c Date: Sat, 24 Jul 2021 09:49:35 +0200 [thread overview] Message-ID: <13453441.4PhDYAFLLM@localhost.localdomain> (raw) In-Reply-To: <CAJuCfpF37KXw2SG37_XoRyhGWc+uueU0NaxcEfU1=FH-rRm+bQ@mail.gmail.com> On Friday, July 23, 2021 10:14:46 PM CEST Suren Baghdasaryan wrote: > On Fri, Jul 23, 2021 at 1:05 PM Fabio M. De Francesco > > <firstname.lastname@example.org> wrote: > > Remove variable 'inode' tnat is set but unused. Issue detected > > by building with warning option -Wunused-but-set-variable. > > > > [...] > > > > - inode = file_inode(vmfile); > > > > lockdep_set_class(&inode->i_rwsem, &backing_shmem_inode_class); > > How about its usage in the above lockdep_set_class(&inode->i_rwsem, > ...) call? I'm sorry. I didn't notice that 'inode' is used soon after assignment, just in the line that follows it. I was also too confident that rebuilding the driver would have triggered an error if it is used somewhere else. I was obviously wrong. Furthermore, I usually automatically search with grep or other tools for other occurrences of a symbol in the function and the file, but this time I must have forgotten to do that. > I'm guessing you are building with CONFIG_LOCKDEP=n. Actually my .config sets CONFIG_LOCKDEP_SUPPORT=y. Did you refer to this? There is no CONFIG_LOCKDEP in the file. I've just run "make clean && make C=2 -j8 drivers/staging/android/ W=1" one more time and it still builds. How is it possible that the code builds correctly with my configuration? This is the output (the last two lines) of 'make': CC drivers/staging/android/ashmem.o AR drivers/staging/android/built-in. There are no errors or warnings, even with that "lockdep_set_class(&inode- >i_rwsem, &backing_shmem_inode_class);" left as-is after 'inode' removal. I really can't understand what I'm missing. > Have you tried adding __maybe_unused in inode variable definition to > get rid of the warning? > Actually, I didn't know that directive that you mention. I'll read the documentation and, if and where suited, I'll use it. Thanks, Fabio > > > [...] > > -- > > 2.32.0
next prev parent reply other threads:[~2021-07-24 7:49 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-23 20:05 Fabio M. De Francesco 2021-07-23 20:14 ` Suren Baghdasaryan 2021-07-24 7:49 ` Fabio M. De Francesco [this message] 2021-07-26 13:44 ` Dan Carpenter 2021-07-28 12:00 ` Fabio M. De Francesco 2021-07-24 2:53 ` kernel test robot 2021-07-24 3:14 ` kernel test robot
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