Re: [PATCH] s390: allow reschedule on syscall restart

Christian Borntraeger [off-list ref] writes:

On 21.01.21 15:39, Sven Schnelle wrote:

quoted

Commit 845f44e8ef28 ("sched: Report local wake up on resched blind zone
within idle loop") from next-20210121 causes a warning because s390
doesn't call sched_resched_local_allow() when restarting a syscall.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
---
 arch/s390/kernel/syscall.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/s390/kernel/syscall.c b/arch/s390/kernel/syscall.c
index bc8e650e377d..2b39ac40f970 100644
--- a/arch/s390/kernel/syscall.c
+++ b/arch/s390/kernel/syscall.c

@@ -162,6 +162,7 @@ void noinstr __do_syscall(struct pt_regs *regs, int per_trap)
 		do_syscall(regs);
 		if (!test_pt_regs_flag(regs, PIF_SYSCALL_RESTART))
 			break;
+		sched_resched_local_allow();
 		local_irq_enable();
 	}
 	exit_to_user_mode();

Yesterdays next now fails with


arch/s390/kernel/syscall.c: In function '__do_syscall':
arch/s390/kernel/syscall.c:165:3: error: implicit declaration of function 'sched_resched_local_allow' [-Werror=implicit-function-declaration]
  165 |   sched_resched_local_allow();
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
make[2]: *** [scripts/Makefile.build:288: arch/s390/kernel/syscall.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [scripts/Makefile.build:530: arch/s390/kernel] Error 2
make[1]: *** Waiting for unfinished jobs....

Looks to me like 845f44e8ef28 ("sched: Report local wake up on resched
blind zone") was removed from linux-next. Stephen, can you remove my
commit as well? It is no longer needed.

Thanks
Sven