Hi all, On Mon, 20 Sep 2021 18:30:16 +1000 Stephen Rothwell wrote: > > On Mon, 20 Sep 2021 14:55:29 +0800 Yafang Shao wrote: > > > > On Mon, Sep 20, 2021 at 9:33 AM Stephen Rothwell wrote: > > > > > > After merging the tip tree, today's linux-next build (powerpc_ppc64 > > > defconfig) produced this warning: > > > > > > kernel/sched/debug.c: In function 'print_cfs_group_stats': > > > kernel/sched/debug.c:460:41: warning: unused variable 'stats' [-Wunused-variable] > > > 460 | struct sched_statistics *stats = __schedstats_from_se(se); > > > | ^~~~~ > > > > > > Caused by commit > > > > > > cb3e971c435d ("sched: Make struct sched_statistics independent of fair sched class") > > > > > > # CONFIG_SCHEDSTATS is not set > > > > > > > Thanks for the report. > > > > We have discussed this issue before[1]. > > This warning happens when CONFIG_SCHEDSTATS is not set and > > schedstat_enabled() is 0, so the whole scope should be not compiled. > > It seems that we don't need to fix this warning. > > > > [1]. https://lore.kernel.org/lkml/20210911082505.115758-1-laoar.shao@gmail.com/ > > Clearly it will be compiled if CONFIG_SCHEDSTATS is not set as that is > exactly what this build has ... even sections of code guarded by "if > (0)" are compiled, they may just not produce any output in the binary. > > Also, I do not have W=1 for this build. > > If you turned schedstat_val() into a static inline function, then this > warning would go away. That also means that argument types and return > values will be better checked. I take it back, that won't work :-( > So, please fix this. Still it needs to be fixed to keep unnecessary warnings out of our builds. -- Cheers, Stephen Rothwell