Re: [PATCH V3] fix a warning on kernel/trace/trace_branch.c andtrace_hw_branches.c

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 2009-10-08 at 08:52 +0800, Li Zefan wrote:
> Zhenwen Xu wrote:
> > fix warnings that caused the API change of trace_buffer_lock_reserve()
> > change files: kernel/trace/trace_hw_branch.c
> > 	      kernel/trace/trace_branch.c
> > 
> > Signed-off-by: Zhenwen Xu <helight.xu@gmail.com>
> > ---
> >  kernel/trace/trace_branch.c      |    2 +-
> >  kernel/trace/trace_hw_branches.c |    6 ++++--
> >  2 files changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
> > index 7a7a9fd..216e2dd 100644
> > --- a/kernel/trace/trace_branch.c
> > +++ b/kernel/trace/trace_branch.c
> > @@ -54,7 +54,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
> >  		goto out;
> >  
> >  	pc = preempt_count();
> > -	event = trace_buffer_lock_reserve(tr, TRACE_BRANCH,
> > +	event = trace_buffer_lock_reserve(tr->buffer, TRACE_BRANCH,
> >  					  sizeof(*entry), flags, pc);
> 
> As Steven has picked up the previous patch, this part can be removed now.

Actually, you can keep it in. Since I noticed that this requires the
local "buffer" variable, I decided not to pull it in yet.


> 
> >  	if (!event)
> >  		goto out;
> > diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
> > index 23b6385..e40f5fb 100644
> > --- a/kernel/trace/trace_hw_branches.c
> > +++ b/kernel/trace/trace_hw_branches.c
> > @@ -165,6 +165,7 @@ void trace_hw_branch(u64 from, u64 to)
> >  	struct ftrace_event_call *call = &event_hw_branch;
> >  	struct trace_array *tr = hw_branch_trace;
> >  	struct ring_buffer_event *event;
> > +	struct ring_buffer      *buf;
> 
> Just use one space:
> 
>  +	struct ring_buffer *buf;
> 
> >  	struct hw_branch_entry *entry;
> >  	unsigned long irq1;
> >  	int cpu;
> > @@ -180,7 +181,8 @@ void trace_hw_branch(u64 from, u64 to)
> >  	if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
> >  		goto out;
> >  
> > -	event = trace_buffer_lock_reserve(tr, TRACE_HW_BRANCHES,
> > +	buf = tr->buffer
> > +	event = trace_buffer_lock_reserve(buf, TRACE_HW_BRANCHES,
> >  					  sizeof(*entry), 0, 0);
> >  	if (!event)
> >  		goto out;
> > @@ -190,7 +192,7 @@ void trace_hw_branch(u64 from, u64 to)
> >  	entry->from = from;
> >  	entry->to   = to;
> >  	if (!filter_check_discard(call, entry, tr->buffer, event))
> 
> s/tr->buffer/buf
> 
> > -		trace_buffer_unlock_commit(tr, event, 0, 0);
> > +		trace_buffer_unlock_commit(buf, event, 0, 0);
> >  
> >   out:
> >  	atomic_dec(&tr->data[cpu]->disabled);
> 
> Otherwise looks good.

Yep, I agree.

Looking for the second patch with both files updated.

Thanks,

-- Steve