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From: Paolo Bonzini <pbonzini@redhat.com>
To: paulmck@linux.vnet.ibm.com, riel@redhat.com
Cc: kvm@vger.kernel.org, borntraeger@de.ibm.com,
	linux-kernel@vger.kernel.org, mtosatti@redhat.com,
	mingo@kernel.orgm, ak@linux.intel.com, oleg@redhat.com,
	masami.hiramatsu.pt@hitachi.com, fweisbec@gmail.com,
	lcapitulino@redhat.com
Subject: Re: [PATCH 1/5] rcu,nohz: add state parameter to context_tracking_user_enter/exit
Date: Fri, 06 Feb 2015 11:15:57 +0100	[thread overview]
Message-ID: <54D4945D.8010703@redhat.com> (raw)
In-Reply-To: <20150205235526.GQ5370@linux.vnet.ibm.com>



On 06/02/2015 00:55, Paul E. McKenney wrote:
> On Thu, Feb 05, 2015 at 03:23:48PM -0500, riel@redhat.com wrote:
>> From: Rik van Riel <riel@redhat.com>
>>
>> Add the expected ctx_state as a parameter to context_tracking_user_enter
>> and context_tracking_user_exit, allowing the same functions to not just
>> track kernel <> user space switching, but also kernel <> guest transitions.
>>
>> Signed-off-by: Rik van Riel <riel@redhat.com>
> 
> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

/me wonders: whose tree is supposed to carry these patches?

Paolo

>> ---
>>  include/linux/context_tracking.h | 12 ++++++------
>>  kernel/context_tracking.c        | 10 +++++-----
>>  2 files changed, 11 insertions(+), 11 deletions(-)
>>
>> diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
>> index 37b81bd51ec0..bd9f000fc98d 100644
>> --- a/include/linux/context_tracking.h
>> +++ b/include/linux/context_tracking.h
>> @@ -10,21 +10,21 @@
>>  #ifdef CONFIG_CONTEXT_TRACKING
>>  extern void context_tracking_cpu_set(int cpu);
>>
>> -extern void context_tracking_user_enter(void);
>> -extern void context_tracking_user_exit(void);
>> +extern void context_tracking_user_enter(enum ctx_state state);
>> +extern void context_tracking_user_exit(enum ctx_state state);
>>  extern void __context_tracking_task_switch(struct task_struct *prev,
>>  					   struct task_struct *next);
>>
>>  static inline void user_enter(void)
>>  {
>>  	if (context_tracking_is_enabled())
>> -		context_tracking_user_enter();
>> +		context_tracking_user_enter(IN_USER);
>>
>>  }
>>  static inline void user_exit(void)
>>  {
>>  	if (context_tracking_is_enabled())
>> -		context_tracking_user_exit();
>> +		context_tracking_user_exit(IN_USER);
>>  }
>>
>>  static inline enum ctx_state exception_enter(void)
>> @@ -35,7 +35,7 @@ static inline enum ctx_state exception_enter(void)
>>  		return 0;
>>
>>  	prev_ctx = this_cpu_read(context_tracking.state);
>> -	context_tracking_user_exit();
>> +	context_tracking_user_exit(prev_ctx);
>>
>>  	return prev_ctx;
>>  }
>> @@ -44,7 +44,7 @@ static inline void exception_exit(enum ctx_state prev_ctx)
>>  {
>>  	if (context_tracking_is_enabled()) {
>>  		if (prev_ctx == IN_USER)
>> -			context_tracking_user_enter();
>> +			context_tracking_user_enter(prev_ctx);
>>  	}
>>  }
>>
>> diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
>> index 937ecdfdf258..4c010787c9ec 100644
>> --- a/kernel/context_tracking.c
>> +++ b/kernel/context_tracking.c
>> @@ -47,7 +47,7 @@ void context_tracking_cpu_set(int cpu)
>>   * to execute won't use any RCU read side critical section because this
>>   * function sets RCU in extended quiescent state.
>>   */
>> -void context_tracking_user_enter(void)
>> +void context_tracking_user_enter(enum ctx_state state)
>>  {
>>  	unsigned long flags;
>>
>> @@ -75,7 +75,7 @@ void context_tracking_user_enter(void)
>>  	WARN_ON_ONCE(!current->mm);
>>
>>  	local_irq_save(flags);
>> -	if ( __this_cpu_read(context_tracking.state) != IN_USER) {
>> +	if ( __this_cpu_read(context_tracking.state) != state) {
>>  		if (__this_cpu_read(context_tracking.active)) {
>>  			trace_user_enter(0);
>>  			/*
>> @@ -101,7 +101,7 @@ void context_tracking_user_enter(void)
>>  		 * OTOH we can spare the calls to vtime and RCU when context_tracking.active
>>  		 * is false because we know that CPU is not tickless.
>>  		 */
>> -		__this_cpu_write(context_tracking.state, IN_USER);
>> +		__this_cpu_write(context_tracking.state, state);
>>  	}
>>  	local_irq_restore(flags);
>>  }
>> @@ -118,7 +118,7 @@ NOKPROBE_SYMBOL(context_tracking_user_enter);
>>   * This call supports re-entrancy. This way it can be called from any exception
>>   * handler without needing to know if we came from userspace or not.
>>   */
>> -void context_tracking_user_exit(void)
>> +void context_tracking_user_exit(enum ctx_state state)
>>  {
>>  	unsigned long flags;
>>
>> @@ -129,7 +129,7 @@ void context_tracking_user_exit(void)
>>  		return;
>>
>>  	local_irq_save(flags);
>> -	if (__this_cpu_read(context_tracking.state) == IN_USER) {
>> +	if (__this_cpu_read(context_tracking.state) == state) {
>>  		if (__this_cpu_read(context_tracking.active)) {
>>  			/*
>>  			 * We are going to run code that may use RCU. Inform
>> -- 
>> 1.9.3
>>
> 

  reply	other threads:[~2015-02-06 10:16 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-05 20:23 [PATCH v2 0/5] rcu,nohz,kvm: use RCU extended quiescent state when running KVM guest riel
2015-02-05 20:23 ` [PATCH 1/5] rcu,nohz: add state parameter to context_tracking_user_enter/exit riel
2015-02-05 23:55   ` Paul E. McKenney
2015-02-06 10:15     ` Paolo Bonzini [this message]
2015-02-06 13:41       ` Paul E. McKenney
2015-02-06 17:22   ` Frederic Weisbecker
2015-02-06 18:20     ` Rik van Riel
2015-02-06 18:23       ` Frederic Weisbecker
2015-02-06 18:51         ` Rik van Riel
2015-02-06 23:15           ` Frederic Weisbecker
2015-02-07  3:53             ` Rik van Riel
2015-02-07  6:34               ` Paul E. McKenney
2015-02-07  7:14                 ` Paul E. McKenney
2015-02-07  8:30                   ` Frederic Weisbecker
2015-02-07 11:29                     ` Rik van Riel
2015-02-07 20:06                     ` Paul E. McKenney
2015-02-09 15:42                       ` Rik van Riel
2015-02-05 20:23 ` [PATCH 2/5] rcu,nohz: run vtime_user_enter/exit only when state == IN_USER riel
2015-02-05 20:23 ` [PATCH 3/5] nohz,kvm: export context_tracking_user_enter/exit riel
2015-02-05 23:55   ` Paul E. McKenney
2015-02-05 20:23 ` [PATCH 4/5] kvm,rcu,nohz: use RCU extended quiescent state when running KVM guest riel
2015-02-05 23:56   ` Paul E. McKenney
2015-02-06 18:01   ` Frederic Weisbecker
2015-02-06 23:24   ` Frederic Weisbecker
2015-02-05 20:23 ` [PATCH 5/5] nohz: add stub context_tracking_is_enabled riel
2015-02-05 23:56   ` Paul E. McKenney
2015-02-06 13:46 ` [PATCH v2 0/5] rcu,nohz,kvm: use RCU extended quiescent state when running KVM guest Frederic Weisbecker
2015-02-06 13:50   ` Paolo Bonzini
2015-02-06 16:19     ` Paul E. McKenney
2015-02-06 18:09     ` Frederic Weisbecker
2015-02-06 14:56   ` Rik van Riel
2015-02-06 18:05     ` Frederic Weisbecker
2015-02-06 15:00 ` Christian Borntraeger
2015-02-06 18:20   ` Frederic Weisbecker

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