| Message ID | 1411711204-8892-1-git-send-email-tiejun.chen@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Il 26/09/2014 08:00, Tiejun Chen ha scritto: > We can use get_cpu() and put_cpu() to replace > preempt_disable()/cpu = smp_processor_id() and > preempt_enable() for slightly better code. > > Signed-off-by: Tiejun Chen <tiejun.chen@intel.com> > --- > arch/x86/kernel/kvmclock.c | 19 ++++++++----------- > 1 file changed, 8 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index d9156ce..0bf3467 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -59,13 +59,12 @@ static void kvm_get_wallclock(struct timespec *now) > > native_write_msr(msr_kvm_wall_clock, low, high); > > - preempt_disable(); > - cpu = smp_processor_id(); > + cpu = get_cpu(); > > vcpu_time = &hv_clock[cpu].pvti; > pvclock_read_wallclock(&wall_clock, vcpu_time, now); > > - preempt_enable(); > + put_cpu(); > } > > static int kvm_set_wallclock(const struct timespec *now) > @@ -107,11 +106,10 @@ static unsigned long kvm_get_tsc_khz(void) > int cpu; > unsigned long tsc_khz; > > - preempt_disable(); > - cpu = smp_processor_id(); > + cpu = get_cpu(); > src = &hv_clock[cpu].pvti; > tsc_khz = pvclock_tsc_khz(src); > - preempt_enable(); > + put_cpu(); > return tsc_khz; > } > > @@ -284,23 +282,22 @@ int __init kvm_setup_vsyscall_timeinfo(void) > > size = PAGE_ALIGN(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS); > > - preempt_disable(); > - cpu = smp_processor_id(); > + cpu = get_cpu(); > > vcpu_time = &hv_clock[cpu].pvti; > flags = pvclock_read_flags(vcpu_time); > > if (!(flags & PVCLOCK_TSC_STABLE_BIT)) { > - preempt_enable(); > + put_cpu(); > return 1; > } > > if ((ret = pvclock_init_vsyscall(hv_clock, size))) { > - preempt_enable(); > + put_cpu(); > return ret; > } > > - preempt_enable(); > + put_cpu(); > > kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK; > #endif > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> but will wait for 3.19. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 26/09/2014 08:00, Tiejun Chen wrote: > We can use get_cpu() and put_cpu() to replace > preempt_disable()/cpu = smp_processor_id() and > preempt_enable() for slightly better code. > > Signed-off-by: Tiejun Chen <tiejun.chen@intel.com> > --- > arch/x86/kernel/kvmclock.c | 19 ++++++++----------- > 1 file changed, 8 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index d9156ce..0bf3467 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -59,13 +59,12 @@ static void kvm_get_wallclock(struct timespec *now) > > native_write_msr(msr_kvm_wall_clock, low, high); > > - preempt_disable(); > - cpu = smp_processor_id(); > + cpu = get_cpu(); > > vcpu_time = &hv_clock[cpu].pvti; > pvclock_read_wallclock(&wall_clock, vcpu_time, now); > > - preempt_enable(); > + put_cpu(); > } > > static int kvm_set_wallclock(const struct timespec *now) > @@ -107,11 +106,10 @@ static unsigned long kvm_get_tsc_khz(void) > int cpu; > unsigned long tsc_khz; > > - preempt_disable(); > - cpu = smp_processor_id(); > + cpu = get_cpu(); > src = &hv_clock[cpu].pvti; > tsc_khz = pvclock_tsc_khz(src); > - preempt_enable(); > + put_cpu(); > return tsc_khz; > } > > @@ -284,23 +282,22 @@ int __init kvm_setup_vsyscall_timeinfo(void) > > size = PAGE_ALIGN(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS); > > - preempt_disable(); > - cpu = smp_processor_id(); > + cpu = get_cpu(); > > vcpu_time = &hv_clock[cpu].pvti; > flags = pvclock_read_flags(vcpu_time); > > if (!(flags & PVCLOCK_TSC_STABLE_BIT)) { > - preempt_enable(); > + put_cpu(); > return 1; > } > > if ((ret = pvclock_init_vsyscall(hv_clock, size))) { > - preempt_enable(); > + put_cpu(); > return ret; > } > > - preempt_enable(); > + put_cpu(); > > kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK; > #endif > Thanks, applied at last. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index d9156ce..0bf3467 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -59,13 +59,12 @@ static void kvm_get_wallclock(struct timespec *now) native_write_msr(msr_kvm_wall_clock, low, high); - preempt_disable(); - cpu = smp_processor_id(); + cpu = get_cpu(); vcpu_time = &hv_clock[cpu].pvti; pvclock_read_wallclock(&wall_clock, vcpu_time, now); - preempt_enable(); + put_cpu(); } static int kvm_set_wallclock(const struct timespec *now) @@ -107,11 +106,10 @@ static unsigned long kvm_get_tsc_khz(void) int cpu; unsigned long tsc_khz; - preempt_disable(); - cpu = smp_processor_id(); + cpu = get_cpu(); src = &hv_clock[cpu].pvti; tsc_khz = pvclock_tsc_khz(src); - preempt_enable(); + put_cpu(); return tsc_khz; } @@ -284,23 +282,22 @@ int __init kvm_setup_vsyscall_timeinfo(void) size = PAGE_ALIGN(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS); - preempt_disable(); - cpu = smp_processor_id(); + cpu = get_cpu(); vcpu_time = &hv_clock[cpu].pvti; flags = pvclock_read_flags(vcpu_time); if (!(flags & PVCLOCK_TSC_STABLE_BIT)) { - preempt_enable(); + put_cpu(); return 1; } if ((ret = pvclock_init_vsyscall(hv_clock, size))) { - preempt_enable(); + put_cpu(); return ret; } - preempt_enable(); + put_cpu(); kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK; #endif
We can use get_cpu() and put_cpu() to replace preempt_disable()/cpu = smp_processor_id() and preempt_enable() for slightly better code. Signed-off-by: Tiejun Chen <tiejun.chen@intel.com> --- arch/x86/kernel/kvmclock.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-)