Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Arnd Bergmann]

On Friday, September 16, 2016 10:53:09 AM CEST Will Deacon wrote:
> On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
> > Hi Will and Steven,
> > 
> > May I have a review or an acked-by from you on this patch so that Arnd
> > can pick it up.
> > 
> > I have tested this patch on arm qemu, I'm sure it can solve the
> > problem described in commit message.
> 
> It looks fine to me; we took your equivalent patch for arm64 already, so:
> 
> Acked-by: Will Deacon 
> 

Applied to my asm-generic tree now, sorry for the delay,

Arnd

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Arnd Bergmann]

On Friday, September 16, 2016 10:53:09 AM CEST Will Deacon wrote:
> On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
> > Hi Will and Steven,
> > 
> > May I have a review or an acked-by from you on this patch so that Arnd
> > can pick it up.
> > 
> > I have tested this patch on arm qemu, I'm sure it can solve the
> > problem described in commit message.
> 
> It looks fine to me; we took your equivalent patch for arm64 already, so:
> 
> Acked-by: Will Deacon 
> 

Applied to my asm-generic tree now, sorry for the delay,

Arnd

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Steven Rostedt]

On Fri, 16 Sep 2016 10:53:09 +0100
Will Deacon  wrote:

> On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
> > Hi Will and Steven,
> > 
> > May I have a review or an acked-by from you on this patch so that Arnd
> > can pick it up.
> > 
> > I have tested this patch on arm qemu, I'm sure it can solve the
> > problem described in commit message.  
> 
> It looks fine to me; we took your equivalent patch for arm64 already, so:
> 

Looks good to me too.

Acked-by: Steven Rostedt 

-- Steve

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Steven Rostedt]

On Fri, 16 Sep 2016 10:53:09 +0100
Will Deacon  wrote:

> On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
> > Hi Will and Steven,
> > 
> > May I have a review or an acked-by from you on this patch so that Arnd
> > can pick it up.
> > 
> > I have tested this patch on arm qemu, I'm sure it can solve the
> > problem described in commit message.  
> 
> It looks fine to me; we took your equivalent patch for arm64 already, so:
> 

Looks good to me too.

Acked-by: Steven Rostedt 

-- Steve

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Chunyan Zhang]

On 16 September 2016 at 17:53, Will Deacon  wrote:
> On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
>> Hi Will and Steven,
>>
>> May I have a review or an acked-by from you on this patch so that Arnd
>> can pick it up.
>>
>> I have tested this patch on arm qemu, I'm sure it can solve the
>> problem described in commit message.
>
> It looks fine to me; we took your equivalent patch for arm64 already, so:

Yeah, I saw that.

>
> Acked-by: Will Deacon 

Thanks,
Chunyan

>
> Will
>
>> On 10 September 2016 at 16:45, Chunyan Zhang  
>> wrote:
>> > When debug preempt or preempt tracer is enabled, preempt_count_add/sub()
>> > can be traced by function and function graph tracing, and
>> > preempt_disable/enable() would call preempt_count_add/sub(), so
>> > we should use preempt_disable/enable_notrace in Ftrace subsystem.
>> >
>> > The function this_cpu_read() started being used by function graph tracing
>> > after the commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the
>> > bitmap like events do"), so it has to use preempt_disable/enable_notrace
>> > instead now.
>> >
>> > Signed-off-by: Chunyan Zhang 
>> > ---
>> >  include/asm-generic/percpu.h | 4 ++--
>> >  1 file changed, 2 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
>> > index 4d9f233..70fefec 100644
>> > --- a/include/asm-generic/percpu.h
>> > +++ b/include/asm-generic/percpu.h
>> > @@ -108,9 +108,9 @@ do {   
>> >  \
>> >  #define this_cpu_generic_read(pcp) \
>> >  ({ \
>> > typeof(pcp) __ret;  \
>> > -   preempt_disable();  \
>> > +   preempt_disable_notrace();  \
>> > __ret = *this_cpu_ptr(&(pcp));  \
>> > -   preempt_enable();   \
>> > +   preempt_enable_notrace();   \
>> > __ret;  \
>> >  })
>> >
>> > --
>> > 2.7.4
>> >
>>

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Chunyan Zhang]

On 16 September 2016 at 17:53, Will Deacon  wrote:
> On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
>> Hi Will and Steven,
>>
>> May I have a review or an acked-by from you on this patch so that Arnd
>> can pick it up.
>>
>> I have tested this patch on arm qemu, I'm sure it can solve the
>> problem described in commit message.
>
> It looks fine to me; we took your equivalent patch for arm64 already, so:

Yeah, I saw that.

>
> Acked-by: Will Deacon 

Thanks,
Chunyan

>
> Will
>
>> On 10 September 2016 at 16:45, Chunyan Zhang  
>> wrote:
>> > When debug preempt or preempt tracer is enabled, preempt_count_add/sub()
>> > can be traced by function and function graph tracing, and
>> > preempt_disable/enable() would call preempt_count_add/sub(), so
>> > we should use preempt_disable/enable_notrace in Ftrace subsystem.
>> >
>> > The function this_cpu_read() started being used by function graph tracing
>> > after the commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the
>> > bitmap like events do"), so it has to use preempt_disable/enable_notrace
>> > instead now.
>> >
>> > Signed-off-by: Chunyan Zhang 
>> > ---
>> >  include/asm-generic/percpu.h | 4 ++--
>> >  1 file changed, 2 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
>> > index 4d9f233..70fefec 100644
>> > --- a/include/asm-generic/percpu.h
>> > +++ b/include/asm-generic/percpu.h
>> > @@ -108,9 +108,9 @@ do {   
>> >  \
>> >  #define this_cpu_generic_read(pcp) \
>> >  ({ \
>> > typeof(pcp) __ret;  \
>> > -   preempt_disable();  \
>> > +   preempt_disable_notrace();  \
>> > __ret = *this_cpu_ptr(&(pcp));  \
>> > -   preempt_enable();   \
>> > +   preempt_enable_notrace();   \
>> > __ret;  \
>> >  })
>> >
>> > --
>> > 2.7.4
>> >
>>

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Will Deacon]

On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
> Hi Will and Steven,
> 
> May I have a review or an acked-by from you on this patch so that Arnd
> can pick it up.
> 
> I have tested this patch on arm qemu, I'm sure it can solve the
> problem described in commit message.

It looks fine to me; we took your equivalent patch for arm64 already, so:

Acked-by: Will Deacon 

Will

> On 10 September 2016 at 16:45, Chunyan Zhang  wrote:
> > When debug preempt or preempt tracer is enabled, preempt_count_add/sub()
> > can be traced by function and function graph tracing, and
> > preempt_disable/enable() would call preempt_count_add/sub(), so
> > we should use preempt_disable/enable_notrace in Ftrace subsystem.
> >
> > The function this_cpu_read() started being used by function graph tracing
> > after the commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the
> > bitmap like events do"), so it has to use preempt_disable/enable_notrace
> > instead now.
> >
> > Signed-off-by: Chunyan Zhang 
> > ---
> >  include/asm-generic/percpu.h | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
> > index 4d9f233..70fefec 100644
> > --- a/include/asm-generic/percpu.h
> > +++ b/include/asm-generic/percpu.h
> > @@ -108,9 +108,9 @@ do {
> > \
> >  #define this_cpu_generic_read(pcp) \
> >  ({ \
> > typeof(pcp) __ret;  \
> > -   preempt_disable();  \
> > +   preempt_disable_notrace();  \
> > __ret = *this_cpu_ptr(&(pcp));  \
> > -   preempt_enable();   \
> > +   preempt_enable_notrace();   \
> > __ret;  \
> >  })
> >
> > --
> > 2.7.4
> >
> 

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Will Deacon]

On Fri, Sep 16, 2016 at 04:42:44PM +0800, Chunyan Zhang wrote:
> Hi Will and Steven,
> 
> May I have a review or an acked-by from you on this patch so that Arnd
> can pick it up.
> 
> I have tested this patch on arm qemu, I'm sure it can solve the
> problem described in commit message.

It looks fine to me; we took your equivalent patch for arm64 already, so:

Acked-by: Will Deacon 

Will

> On 10 September 2016 at 16:45, Chunyan Zhang  wrote:
> > When debug preempt or preempt tracer is enabled, preempt_count_add/sub()
> > can be traced by function and function graph tracing, and
> > preempt_disable/enable() would call preempt_count_add/sub(), so
> > we should use preempt_disable/enable_notrace in Ftrace subsystem.
> >
> > The function this_cpu_read() started being used by function graph tracing
> > after the commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the
> > bitmap like events do"), so it has to use preempt_disable/enable_notrace
> > instead now.
> >
> > Signed-off-by: Chunyan Zhang 
> > ---
> >  include/asm-generic/percpu.h | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
> > index 4d9f233..70fefec 100644
> > --- a/include/asm-generic/percpu.h
> > +++ b/include/asm-generic/percpu.h
> > @@ -108,9 +108,9 @@ do {
> > \
> >  #define this_cpu_generic_read(pcp) \
> >  ({ \
> > typeof(pcp) __ret;  \
> > -   preempt_disable();  \
> > +   preempt_disable_notrace();  \
> > __ret = *this_cpu_ptr(&(pcp));  \
> > -   preempt_enable();   \
> > +   preempt_enable_notrace();   \
> > __ret;  \
> >  })
> >
> > --
> > 2.7.4
> >
> 

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Chunyan Zhang]

Hi Will and Steven,

May I have a review or an acked-by from you on this patch so that Arnd
can pick it up.

I have tested this patch on arm qemu, I'm sure it can solve the
problem described in commit message.


Thanks,
Chunyan


On 10 September 2016 at 16:45, Chunyan Zhang  wrote:
> When debug preempt or preempt tracer is enabled, preempt_count_add/sub()
> can be traced by function and function graph tracing, and
> preempt_disable/enable() would call preempt_count_add/sub(), so
> we should use preempt_disable/enable_notrace in Ftrace subsystem.
>
> The function this_cpu_read() started being used by function graph tracing
> after the commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the
> bitmap like events do"), so it has to use preempt_disable/enable_notrace
> instead now.
>
> Signed-off-by: Chunyan Zhang 
> ---
>  include/asm-generic/percpu.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
> index 4d9f233..70fefec 100644
> --- a/include/asm-generic/percpu.h
> +++ b/include/asm-generic/percpu.h
> @@ -108,9 +108,9 @@ do {  
>   \
>  #define this_cpu_generic_read(pcp) \
>  ({ \
> typeof(pcp) __ret;  \
> -   preempt_disable();  \
> +   preempt_disable_notrace();  \
> __ret = *this_cpu_ptr(&(pcp));  \
> -   preempt_enable();   \
> +   preempt_enable_notrace();   \
> __ret;  \
>  })
>
> --
> 2.7.4
>

Re: [PATCH] percpu: make this_cpu_generic_read notrace

[Chunyan Zhang]

Hi Will and Steven,

May I have a review or an acked-by from you on this patch so that Arnd
can pick it up.

I have tested this patch on arm qemu, I'm sure it can solve the
problem described in commit message.


Thanks,
Chunyan


On 10 September 2016 at 16:45, Chunyan Zhang  wrote:
> When debug preempt or preempt tracer is enabled, preempt_count_add/sub()
> can be traced by function and function graph tracing, and
> preempt_disable/enable() would call preempt_count_add/sub(), so
> we should use preempt_disable/enable_notrace in Ftrace subsystem.
>
> The function this_cpu_read() started being used by function graph tracing
> after the commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the
> bitmap like events do"), so it has to use preempt_disable/enable_notrace
> instead now.
>
> Signed-off-by: Chunyan Zhang 
> ---
>  include/asm-generic/percpu.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
> index 4d9f233..70fefec 100644
> --- a/include/asm-generic/percpu.h
> +++ b/include/asm-generic/percpu.h
> @@ -108,9 +108,9 @@ do {  
>   \
>  #define this_cpu_generic_read(pcp) \
>  ({ \
> typeof(pcp) __ret;  \
> -   preempt_disable();  \
> +   preempt_disable_notrace();  \
> __ret = *this_cpu_ptr(&(pcp));  \
> -   preempt_enable();   \
> +   preempt_enable_notrace();   \
> __ret;  \
>  })
>
> --
> 2.7.4
>