| Message ID | 20100406133141.039454288@chello.nl |
|---|---|
| State | RFC |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Apr 06, 2010 at 03:28:10PM +0200, Peter Zijlstra wrote: > Since we can call cpu_clock() from NMI context fix up the IRQ > disabling to conform to the new rules. > > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > --- > kernel/sched_clock.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Index: linux-2.6/kernel/sched_clock.c > =================================================================== > --- linux-2.6.orig/kernel/sched_clock.c > +++ linux-2.6/kernel/sched_clock.c > @@ -241,9 +241,9 @@ unsigned long long cpu_clock(int cpu) > unsigned long long clock; > unsigned long flags; > > - local_irq_save(flags); > + local_irq_save_nmi(flags); > clock = sched_clock_cpu(cpu); > - local_irq_restore(flags); > + local_irq_restore_nmi(flags); > > return clock; > } That seem to add a small overhead in various places. Do we want to make local_irq_save_nmi == local_irq_save for archs that have native nmi? Or cpu_clock_nmi()? -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2010-04-07 at 13:27 +0200, Frederic Weisbecker wrote: > On Tue, Apr 06, 2010 at 03:28:10PM +0200, Peter Zijlstra wrote: > > Since we can call cpu_clock() from NMI context fix up the IRQ > > disabling to conform to the new rules. > > > > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > > --- > > kernel/sched_clock.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > Index: linux-2.6/kernel/sched_clock.c > > =================================================================== > > --- linux-2.6.orig/kernel/sched_clock.c > > +++ linux-2.6/kernel/sched_clock.c > > @@ -241,9 +241,9 @@ unsigned long long cpu_clock(int cpu) > > unsigned long long clock; > > unsigned long flags; > > > > - local_irq_save(flags); > > + local_irq_save_nmi(flags); > > clock = sched_clock_cpu(cpu); > > - local_irq_restore(flags); > > + local_irq_restore_nmi(flags); > > > > return clock; > > } > > > That seem to add a small overhead in various places. > Do we want to make local_irq_save_nmi == local_irq_save > for archs that have native nmi? That is already so, see 1/3. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Apr 07, 2010 at 01:31:34PM +0200, Peter Zijlstra wrote: > On Wed, 2010-04-07 at 13:27 +0200, Frederic Weisbecker wrote: > > On Tue, Apr 06, 2010 at 03:28:10PM +0200, Peter Zijlstra wrote: > > > Since we can call cpu_clock() from NMI context fix up the IRQ > > > disabling to conform to the new rules. > > > > > > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > > > --- > > > kernel/sched_clock.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > Index: linux-2.6/kernel/sched_clock.c > > > =================================================================== > > > --- linux-2.6.orig/kernel/sched_clock.c > > > +++ linux-2.6/kernel/sched_clock.c > > > @@ -241,9 +241,9 @@ unsigned long long cpu_clock(int cpu) > > > unsigned long long clock; > > > unsigned long flags; > > > > > > - local_irq_save(flags); > > > + local_irq_save_nmi(flags); > > > clock = sched_clock_cpu(cpu); > > > - local_irq_restore(flags); > > > + local_irq_restore_nmi(flags); > > > > > > return clock; > > > } > > > > > > That seem to add a small overhead in various places. > > Do we want to make local_irq_save_nmi == local_irq_save > > for archs that have native nmi? > > That is already so, see 1/3. Ah you're right. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux-2.6/kernel/sched_clock.c =================================================================== --- linux-2.6.orig/kernel/sched_clock.c +++ linux-2.6/kernel/sched_clock.c @@ -241,9 +241,9 @@ unsigned long long cpu_clock(int cpu) unsigned long long clock; unsigned long flags; - local_irq_save(flags); + local_irq_save_nmi(flags); clock = sched_clock_cpu(cpu); - local_irq_restore(flags); + local_irq_restore_nmi(flags); return clock; }
Since we can call cpu_clock() from NMI context fix up the IRQ disabling to conform to the new rules. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> --- kernel/sched_clock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html