Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, 7 Oct 2024 13:06:49 +0800 kernel test robot <lkp@xxxxxxxxx> wrote: > > > Hi Jeongjun, > > > > kernel test robot noticed the following build warnings: > > > > [auto build test WARNING on akpm-mm/mm-everything] > > > > url: https://github.com/intel-lab-lkp/linux/commits/Jeongjun-Park/mm-swap-prevent-possible-data-race-in-__try_to_reclaim_swap/20241004-222733 > > base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything > > patch link: https://lore.kernel.org/r/20241004142504.4379-1-aha310510%40gmail.com > > patch subject: [PATCH] mm: swap: prevent possible data-race in __try_to_reclaim_swap > > config: x86_64-kexec (https://download.01.org/0day-ci/archive/20241007/202410071223.t0yF8vP8-lkp@xxxxxxxxx/config) > > compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff) > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241007/202410071223.t0yF8vP8-lkp@xxxxxxxxx/reproduce) > > > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > > the same patch/commit), kindly add following tags > > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202410071223.t0yF8vP8-lkp@xxxxxxxxx/ > > > > All warnings (new ones prefixed by >>): > > > > >> mm/swapfile.c:203:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > > 203 | if (!folio_trylock(folio)) > > | ^~~~~~~~~~~~~~~~~~~~~ > > mm/swapfile.c:254:9: note: uninitialized use occurs here > > 254 | return ret; > > This warning can't be correct? I think it's correct. Even if folio_trylock fails, the return value should be -nr_pages. Not initializing ret like in the v1 patch goes against the design purpose of the function. So I think it's right to apply the v2 patch that I sent you. Regards, Jeongjun Park
