On Thu, Jul 29, 2021 at 09:36:44AM +0100, Mel Gorman wrote: > On Thu, Jul 15, 2021 at 04:35:35AM +0100, Matthew Wilcox (Oracle) wrote: > > These are the folio equivalents of relock_page_lruvec_irq() and > > folio_lruvec_relock_irqsave(). Also convert page_matches_lruvec() > > to folio_matches_lruvec(). > > > > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> > > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > > When build testing what you had in your for-next branch, I got a new > warning for powerpc defconfig > > In file included from ./include/linux/mmzone.h:8, > from ./include/linux/gfp.h:6, > from ./include/linux/mm.h:10, > from mm/swap.c:17: > mm/swap.c: In function 'release_pages': > ./include/linux/spinlock.h:290:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized] > 290 | _raw_spin_unlock_irqrestore(lock, flags); \ > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > mm/swap.c:906:16: note: 'flags' was declared here > 906 | unsigned long flags; > | ^~~~~ > > I'm fairly sure it's a false positive and the compiler just cannot figure > out that flags are only accessed when lruvec is !NULL and once lruvec is > !NULL, flags are valid Yes, I read it over carefully and I can't see a way in which this can happen. Weird that this change made the compiler unable to figure that out. Pushed out a new for-next with your patch included. Thanks!
