On Thu, Apr 16, 2020 at 06:02:24PM +0100, Will Deacon wrote: > On Thu, Apr 16, 2020 at 08:46:02AM -0700, Matthew Wilcox wrote: > > From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> > > This local definition hasn't been used since commit 84c6591103db > > ("locking/atomics, asm-generic/bitops/lock.h: Rewrite using > > atomic_fetch_*()") which provided a default definition. > > Ok, for my own curiosity I tried building for Alpha because I couldn't for > the life of me figure it out, and behold: > > mm/filemap.c: In function 'unlock_page': > mm/filemap.c:1271:6: error: implicit declaration of function 'clear_bit_unlock_is_negative_byte' [-Werror=implicit-function-declaration] > if (clear_bit_unlock_is_negative_byte(PG_locked, &page->flags)) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: some warnings being treated as errors > > I had to enable CONFIG_SMP, so maybe the robot doesn't do that? > > Anyway, it's somewhat reassuring that it broke, if not unfortunate at the same > time! Thanks! The robot says it built two alpha configs, randconfig-a001-20200325 and defconfig. I imagine neither has SMP set. kbuild people, please can you add SMP and non-SMP options to the configs you test?