On Tue, Jul 30, 2019 at 11:28:01AM -0700, Nathan Chancellor wrote: > On Mon, Jul 29, 2019 at 09:19:05PM +0200, Greg Kroah-Hartman wrote: > > [ Upstream commit 509466b7d480bc5d22e90b9fbe6122ae0e2fbe39 ] > > > > runnable_avg_yN_inv[] is only used in kernel/sched/pelt.c but was > > included in several other places because they need other macros all > > came from kernel/sched/sched-pelt.h which was generated by > > Documentation/scheduler/sched-pelt. As the result, it causes compilation > > a lot of warnings, > > > > kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=] > > kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=] > > kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=] > > ... > > > > Silence it by appending the __maybe_unused attribute for it, so all > > generated variables and macros can still be kept in the same file. > > > > Signed-off-by: Qian Cai <cai@xxxxxx> > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Link: https://lkml.kernel.org/r/1559596304-31581-1-git-send-email-cai@xxxxxx > > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > --- > > Documentation/scheduler/sched-pelt.c | 3 ++- > > kernel/sched/sched-pelt.h | 2 +- > > 2 files changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/Documentation/scheduler/sched-pelt.c b/Documentation/scheduler/sched-pelt.c > > index e4219139386a..7238b355919c 100644 > > --- a/Documentation/scheduler/sched-pelt.c > > +++ b/Documentation/scheduler/sched-pelt.c > > @@ -20,7 +20,8 @@ void calc_runnable_avg_yN_inv(void) > > int i; > > unsigned int x; > > > > - printf("static const u32 runnable_avg_yN_inv[] = {"); > > + /* To silence -Wunused-but-set-variable warnings. */ > > + printf("static const u32 runnable_avg_yN_inv[] __maybe_unused = {"); > > for (i = 0; i < HALFLIFE; i++) { > > x = ((1UL<<32)-1)*pow(y, i); > > > > diff --git a/kernel/sched/sched-pelt.h b/kernel/sched/sched-pelt.h > > index a26473674fb7..c529706bed11 100644 > > --- a/kernel/sched/sched-pelt.h > > +++ b/kernel/sched/sched-pelt.h > > @@ -1,7 +1,7 @@ > > /* SPDX-License-Identifier: GPL-2.0 */ > > /* Generated by Documentation/scheduler/sched-pelt; do not modify. */ > > > > -static const u32 runnable_avg_yN_inv[] = { > > +static const u32 runnable_avg_yN_inv[] __maybe_unused = { > > 0xffffffff, 0xfa83b2da, 0xf5257d14, 0xefe4b99a, 0xeac0c6e6, 0xe5b906e6, > > 0xe0ccdeeb, 0xdbfbb796, 0xd744fcc9, 0xd2a81d91, 0xce248c14, 0xc9b9bd85, > > 0xc5672a10, 0xc12c4cc9, 0xbd08a39e, 0xb8fbaf46, 0xb504f333, 0xb123f581, > > -- > > 2.20.1 > > > > > > > > This patch does nothing in 4.14. There is no kernel/sched/pelt.c. > > $ fd pelt > kernel/sched/sched-pelt.h > Documentation/scheduler/sched-pelt.c > > runnable_avg_yN_inv is only used in one location in 4.14.134, in fair.c > behind CONFIG_SMP, which is also the guard that includes sched-pelt.h. > > $ rg --no-heading -g '!Documentation' runnable_avg_yN_inv > kernel/sched/sched-pelt.h:4:static const u32 runnable_avg_yN_inv[] = { > kernel/sched/fair.c:2849: val = mul_u64_u32_shr(val, runnable_avg_yN_inv[local_n], 32); > > $ rg --no-heading -B 2 "sched-pelt.h" > kernel/sched/fair.c-707-#ifdef CONFIG_SMP > kernel/sched/fair.c-708- > kernel/sched/fair.c:709:#include "sched-pelt.h" > > I see no way for the warnings in this patch to occur here, making it > pointless. I get two trivial conflicts in my msm-4.14 tree from this > patch that I would like to avoid dealing with. > > Please consider dropping this patch, thanks! Now dropped, thanks. greg k-h
