[PATCH] btrfs: remove unused pages_processed variable

[PATCH] btrfs: remove unused pages_processed variable

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

The only user of pages_processed was removed, so it's now a local write-only
variable that can be eliminated as well:

fs/btrfs/extent_io.c:214:16: error: variable 'pages_processed' set but not used [-Werror,-Wunused-but-set-variable]

Fixes: 9480af8687200 ("btrfs: split page locking out of __process_pages_contig")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307241541.8w52nEnt-lkp@intel.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/btrfs/extent_io.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c0440a0988c9a..121edea2cfe85 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -211,7 +211,6 @@ static void __process_pages_contig(struct address_space *mapping,
 	pgoff_t start_index = start >> PAGE_SHIFT;
 	pgoff_t end_index = end >> PAGE_SHIFT;
 	pgoff_t index = start_index;
-	unsigned long pages_processed = 0;
 	struct folio_batch fbatch;
 	int i;
 
@@ -226,7 +225,6 @@ static void __process_pages_contig(struct address_space *mapping,
 
 			process_one_page(fs_info, &folio->page, locked_page,
 					 page_ops, start, end);
-			pages_processed += folio_nr_pages(folio);
 		}
 		folio_batch_release(&fbatch);
 		cond_resched();
-- 
2.39.2

Re: [PATCH] btrfs: remove unused pages_processed variable

[Christoph Hellwig]

On Mon, Jul 24, 2023 at 02:19:15PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The only user of pages_processed was removed, so it's now a local write-only
> variable that can be eliminated as well:

Hmm, I thought I had fixed this up, but obviously that version didn't
end up in for-next, probably due to a faul on my side..

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH] btrfs: remove unused pages_processed variable

[Nick Desaulniers]

On Mon, Jul 24, 2023 at 02:19:15PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The only user of pages_processed was removed, so it's now a local write-only
> variable that can be eliminated as well:
> 
> fs/btrfs/extent_io.c:214:16: error: variable 'pages_processed' set but not used [-Werror,-Wunused-but-set-variable]
> 
> Fixes: 9480af8687200 ("btrfs: split page locking out of __process_pages_contig")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202307241541.8w52nEnt-lkp@intel.com/
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for the patch!
Reported-by: kernelci.org bot <bot@kernelci.org>
Link: https://lore.kernel.org/llvm/64c00cd4.630a0220.6ad79.0eac@mx.google.com/
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>  fs/btrfs/extent_io.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index c0440a0988c9a..121edea2cfe85 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -211,7 +211,6 @@ static void __process_pages_contig(struct address_space *mapping,
>  	pgoff_t start_index = start >> PAGE_SHIFT;
>  	pgoff_t end_index = end >> PAGE_SHIFT;
>  	pgoff_t index = start_index;
> -	unsigned long pages_processed = 0;
>  	struct folio_batch fbatch;
>  	int i;
>  
> @@ -226,7 +225,6 @@ static void __process_pages_contig(struct address_space *mapping,
>  
>  			process_one_page(fs_info, &folio->page, locked_page,
>  					 page_ops, start, end);
> -			pages_processed += folio_nr_pages(folio);
>  		}
>  		folio_batch_release(&fbatch);
>  		cond_resched();
> -- 
> 2.39.2
> 

Re: [PATCH] btrfs: remove unused pages_processed variable

[Nick Desaulniers]

On Tue, Jul 25, 2023 at 2:49 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Mon, Jul 24, 2023 at 02:19:15PM +0200, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > The only user of pages_processed was removed, so it's now a local write-only
> > variable that can be eliminated as well:
> >
> > fs/btrfs/extent_io.c:214:16: error: variable 'pages_processed' set but not used [-Werror,-Wunused-but-set-variable]
> >
> > Fixes: 9480af8687200 ("btrfs: split page locking out of __process_pages_contig")
> > Reported-by: kernel test robot <lkp@intel.com>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202307241541.8w52nEnt-lkp@intel.com/
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
> Thanks for the patch!
> Reported-by: kernelci.org bot <bot@kernelci.org>
> Link: https://lore.kernel.org/llvm/64c00cd4.630a0220.6ad79.0eac@mx.google.com/
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

Friendly ping the btrfs maintainers to please pick this up.  Our CI
for linux-next has been red over this for longer than I like, and it's
giving me nausea, heartburn, indigestion, upset stomach, and...well...
https://youtu.be/d8InOVEsMlU

>
> > ---
> >  fs/btrfs/extent_io.c | 2 --
> >  1 file changed, 2 deletions(-)
> >
> > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> > index c0440a0988c9a..121edea2cfe85 100644
> > --- a/fs/btrfs/extent_io.c
> > +++ b/fs/btrfs/extent_io.c
> > @@ -211,7 +211,6 @@ static void __process_pages_contig(struct address_space *mapping,
> >       pgoff_t start_index = start >> PAGE_SHIFT;
> >       pgoff_t end_index = end >> PAGE_SHIFT;
> >       pgoff_t index = start_index;
> > -     unsigned long pages_processed = 0;
> >       struct folio_batch fbatch;
> >       int i;
> >
> > @@ -226,7 +225,6 @@ static void __process_pages_contig(struct address_space *mapping,
> >
> >                       process_one_page(fs_info, &folio->page, locked_page,
> >                                        page_ops, start, end);
> > -                     pages_processed += folio_nr_pages(folio);
> >               }
> >               folio_batch_release(&fbatch);
> >               cond_resched();
> > --
> > 2.39.2
> >



-- 
Thanks,
~Nick Desaulniers

Re: [PATCH] btrfs: remove unused pages_processed variable

[David Sterba]

On Thu, Aug 03, 2023 at 09:45:27AM -0700, Nick Desaulniers wrote:
> On Tue, Jul 25, 2023 at 2:49 PM Nick Desaulniers
> <ndesaulniers@google.com> wrote:
> >
> > On Mon, Jul 24, 2023 at 02:19:15PM +0200, Arnd Bergmann wrote:
> > > From: Arnd Bergmann <arnd@arndb.de>
> > >
> > > The only user of pages_processed was removed, so it's now a local write-only
> > > variable that can be eliminated as well:
> > >
> > > fs/btrfs/extent_io.c:214:16: error: variable 'pages_processed' set but not used [-Werror,-Wunused-but-set-variable]
> > >
> > > Fixes: 9480af8687200 ("btrfs: split page locking out of __process_pages_contig")
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202307241541.8w52nEnt-lkp@intel.com/
> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> >
> > Thanks for the patch!
> > Reported-by: kernelci.org bot <bot@kernelci.org>
> > Link: https://lore.kernel.org/llvm/64c00cd4.630a0220.6ad79.0eac@mx.google.com/
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> 
> Friendly ping the btrfs maintainers to please pick this up.

Fix folded to the original patch, thanks.