On 09/29/2016 03:11 PM, Martin Schwidefsky wrote: > On Thu, 29 Sep 2016 13:54:16 +0200 > Christian Borntraeger <[email protected]> wrote: > >> this implements the s390 backend for commit >> "kernel/sched: introduce vcpu preempted check interface" >> by simply reusing the existing cpu_is_preempted function. >> >> Signed-off-by: Christian Borntraeger <[email protected]> >> --- >> Martin, Heiko, >> >> this patch is a minimal change by not touching all existing users of >> cpu_is_preempted in spinlock.c. If you want it differently, let me >> know. >> >> >> arch/s390/include/asm/spinlock.h | 7 +++++++ >> arch/s390/lib/spinlock.c | 3 ++- >> 2 files changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/arch/s390/include/asm/spinlock.h >> b/arch/s390/include/asm/spinlock.h >> index 63ebf37..6e82986 100644 >> --- a/arch/s390/include/asm/spinlock.h >> +++ b/arch/s390/include/asm/spinlock.h >> @@ -21,6 +21,13 @@ _raw_compare_and_swap(unsigned int *lock, unsigned int >> old, unsigned int new) >> return __sync_bool_compare_and_swap(lock, old, new); >> } >> >> +int arch_vcpu_is_preempted(int cpu); >> +#define vcpu_is_preempted cpu_is_preempted >> +static inline bool cpu_is_preempted(int cpu) >> +{ >> + return arch_vcpu_is_preempted(cpu); >> +} >> + >> /* >> * Simple spin lock operations. There are two variants, one clears IRQ's >> * on the local processor, one does not. >> diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c >> index e5f50a7..9f473c8 100644 >> --- a/arch/s390/lib/spinlock.c >> +++ b/arch/s390/lib/spinlock.c >> @@ -37,7 +37,7 @@ static inline void _raw_compare_and_delay(unsigned int >> *lock, unsigned int old) >> asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock)); >> } >> >> -static inline int cpu_is_preempted(int cpu) >> +int arch_vcpu_is_preempted(int cpu) >> { >> if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu)) >> return 0; >> @@ -45,6 +45,7 @@ static inline int cpu_is_preempted(int cpu) >> return 0; >> return 1; >> } >> +EXPORT_SYMBOL(arch_vcpu_is_preempted); >> >> void arch_spin_lock_wait(arch_spinlock_t *lp) >> { > > Hmm, if I look at the code we now have an additional function for > the spinlock loops. The call arch_vcpu_is_preempted which test > CIF_ENABLED_WAIT and then calls smp_vcpu_scheduled(). The test > used to be inline. > > A better solution would be to move the CIF_ENABLED_WAIT test to the > smp_vcpu_scheduled() function, rename it to arch_vcpu_is_preempted() > and then export that function. The cpu_is_preempted() function is > replaced by arch_vcpu_is_preempted() which does make a lot of sense, > no? >
Yes that makes sense, will spin a v2.
