On Sat, Aug 16, 2014 at 11:26:31AM +0900, Namhyung Kim wrote:

SNIP

> > 
> > hum, where is it callee/caller mixed?  with following example:
> > 
> > ---
> > void c(void)
> > {
> > }
> > 
> > void b(void)
> > {
> >         c();
> > }
> > 
> > void a(void)
> > {
> >         b();
> > }
> > 
> > int main(void)
> > {
> >         while(1) {
> >                 a();
> >                 b();
> >                 c();
> >         }
> > }
> > ---
> > 
> > for 'c' the current code will display:
> > 
> > -   43.74%    43.74%  t        t                 [.] c                      
> >                                                               ▒
> >    - __libc_start_main                                                      
> >                                                               ▒
> >       - 86.33% main                                                         
> >                                                               ▒
> >            67.08% c                                                         
> >                                                               ▒
> >          - 32.91% a                                                         
> >                                                               ▒
> >               99.44% c                                                      
> >                                                               ▒
> >             - 0.56% b                                                       
> >                                                               ▒
> >                  c                                                          
> >                                                               ▒
> >         13.67% c                                                            
> >                                                               ▒
> > 
> > and with this patch:
> > 
> > -   43.74%    43.74%  t        t                 [.] c                      
> >                                                               ▒
> >      c                                                                      
> >                                                               ▒
> > 
> > 
> > The 'c' callchain is still in caller order. IMO we should
> > keep whole callchain here.
> 
> The problem is not in pure self entry (that has self overhead = children
> overhead) and pure cumulative entry (self overhead = 0).  It's in mixed
> entries, please see last two examples in the description 0/3.

right, but it still affects pure entries as well
anyway, let's see the mixed entry

for 'a' the current code will display:
-   31.97%    17.16%  t        t                  [.] a                         
                               ▒
   - __libc_start_main                                                          
                               ◆
        81.08% a                                                                
                               ▒
      - 18.92% main                                                             
                               ▒
           a                                                                    
                               ▒
   - a                                                                          
                               ▒
        85.05% c                                                                
                               ▒
      - 14.91% b                                                                
                               ▒
           100.00% c                                                            
                               ▒

and with this patch:
-   31.97%    17.16%  t        t                  [.] a                         
                               ▒
   - a                                                                          
                               ▒
        85.05% c                                                                
                               ▒
      - 14.91% b                                                                
                               ▒
           100.00% c                                                            
                               ▒

so we'll miss the 'self' callchain of 'a' symbol

if we want to avoid the confusion about 2 different callchains, how
about marking them with 'self' and 'children' tags, instead of removing
one of them, like:

for 'a' the current code will display:
-   31.97%    17.16%  t        t                  [.] a                         
                               ▒
   - [self]
     __libc_start_main                                                          
                               ◆
        81.08% a                                                                
                               ▒
      - 18.92% main                                                             
                               ▒
           a                                                                    
                               ▒
   - [children]
     a                                                                          
                               ▒
        85.05% c                                                                
                               ▒
      - 14.91% b                                                                
                               ▒
           100.00% c                                                            
                               ▒


jirka
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