| Message ID | 1304515864-17105-2-git-send-email-gleb@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, May 04, 2011 at 04:31:03PM +0300, Gleb Natapov wrote: > Provide rcu_virt_note_context_switch() for vitalization use to note > quiescent state during guest entry. Very good, queued on -rcu. Unless you tell me otherwise, I will assume that you want to carry the patch modifying KVM to use this. Thanx, Paul > Signed-off-by: Gleb Natapov <gleb@redhat.com> > --- > include/linux/rcutiny.h | 8 ++++++++ > include/linux/rcutree.h | 10 ++++++++++ > kernel/rcutree.c | 1 + > 3 files changed, 19 insertions(+), 0 deletions(-) > > diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h > index 30ebd7c..52b3e02 100644 > --- a/include/linux/rcutiny.h > +++ b/include/linux/rcutiny.h > @@ -100,6 +100,14 @@ static inline void rcu_note_context_switch(int cpu) > } > > /* > + * Take advantage of the fact that there is only one CPU, which > + * allows us to ignore virtualization-based context switches. > + */ > +static inline void rcu_virt_note_context_switch(int cpu) > +{ > +} > + > +/* > * Return the number of grace periods. > */ > static inline long rcu_batches_completed(void) > diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h > index 3a93348..b2a906e 100644 > --- a/include/linux/rcutree.h > +++ b/include/linux/rcutree.h > @@ -35,6 +35,16 @@ extern void rcu_note_context_switch(int cpu); > extern int rcu_needs_cpu(int cpu); > extern void rcu_cpu_stall_reset(void); > > +/* > + * Note a virtualization-based context switch. This is simply a > + * wrapper around rcu_note_context_switch(), which allows TINY_RCU > + * to save a few bytes. > + */ > +static inline void rcu_virt_note_context_switch(int cpu) > +{ > + rcu_note_context_switch(cpu); > +} > + > #ifdef CONFIG_TREE_PREEMPT_RCU > > extern void exit_rcu(void); > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index dd4aea8..0837d63 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -124,6 +124,7 @@ void rcu_note_context_switch(int cpu) > rcu_sched_qs(cpu); > rcu_preempt_note_context_switch(cpu); > } > +EXPORT_SYMBOL_GPL(rcu_note_context_switch); > > #ifdef CONFIG_NO_HZ > DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { > -- > 1.7.4.4 > -- 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 05/04/2011 07:35 PM, Paul E. McKenney wrote: > On Wed, May 04, 2011 at 04:31:03PM +0300, Gleb Natapov wrote: > > Provide rcu_virt_note_context_switch() for vitalization use to note > > quiescent state during guest entry. > > Very good, queued on -rcu. > > Unless you tell me otherwise, I will assume that you want to carry the > patch modifying KVM to use this. Is -rcu a fast-forward-only tree (like tip)? If so I'll merge it and apply patch 2.
On Mon, May 09, 2011 at 11:51:34AM +0300, Avi Kivity wrote: > On 05/04/2011 07:35 PM, Paul E. McKenney wrote: > >On Wed, May 04, 2011 at 04:31:03PM +0300, Gleb Natapov wrote: > >> Provide rcu_virt_note_context_switch() for vitalization use to note > >> quiescent state during guest entry. > > > >Very good, queued on -rcu. > > > >Unless you tell me otherwise, I will assume that you want to carry the > >patch modifying KVM to use this. > > Is -rcu a fast-forward-only tree (like tip)? If so I'll merge it > and apply patch 2. Yep, -rcu is subject to rebase and feeds into -tip. The patch is SHA 29ce831000081dd757d3116bf774aafffc4b6b20 in git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu.git Branch is rcu/next. My guess is that this commit will show up in -tip soon. Thanx, Paul -- 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/include/linux/rcutiny.h b/include/linux/rcutiny.h index 30ebd7c..52b3e02 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -100,6 +100,14 @@ static inline void rcu_note_context_switch(int cpu) } /* + * Take advantage of the fact that there is only one CPU, which + * allows us to ignore virtualization-based context switches. + */ +static inline void rcu_virt_note_context_switch(int cpu) +{ +} + +/* * Return the number of grace periods. */ static inline long rcu_batches_completed(void) diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 3a93348..b2a906e 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -35,6 +35,16 @@ extern void rcu_note_context_switch(int cpu); extern int rcu_needs_cpu(int cpu); extern void rcu_cpu_stall_reset(void); +/* + * Note a virtualization-based context switch. This is simply a + * wrapper around rcu_note_context_switch(), which allows TINY_RCU + * to save a few bytes. + */ +static inline void rcu_virt_note_context_switch(int cpu) +{ + rcu_note_context_switch(cpu); +} + #ifdef CONFIG_TREE_PREEMPT_RCU extern void exit_rcu(void); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index dd4aea8..0837d63 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -124,6 +124,7 @@ void rcu_note_context_switch(int cpu) rcu_sched_qs(cpu); rcu_preempt_note_context_switch(cpu); } +EXPORT_SYMBOL_GPL(rcu_note_context_switch); #ifdef CONFIG_NO_HZ DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
Provide rcu_virt_note_context_switch() for vitalization use to note quiescent state during guest entry. Signed-off-by: Gleb Natapov <gleb@redhat.com> --- include/linux/rcutiny.h | 8 ++++++++ include/linux/rcutree.h | 10 ++++++++++ kernel/rcutree.c | 1 + 3 files changed, 19 insertions(+), 0 deletions(-)