Re: [RFC 5/5] perf: Enable multiple hist_entry_group output

[Don Zickus <dzickus@redhat.com>]

On Fri, Apr 11, 2014 at 07:30:00PM +0200, Jiri Olsa wrote:
> On Thu, Apr 10, 2014 at 04:11:01PM -0400, Don Zickus wrote:
> > Enable multiple hist_entry_group groups in the output based on a sort
> > method.
> > 
> > Currently only 'perf report' is hooked in with '--group-sort='.  The choices
> > are cpu, pid, and cacheline.  Only --stdio works right now.  I haven't figured
> > out how the other outputs work.
> > 
> > Sample output from 'perf mem record -a grep -r foo /* > /dev/null'
> > 
> > (normal) perf mem report --percent-limit=1.0 --stdio
> > 
> >  Overhead       Samples
> >   Local Weight             Memory access                                      Symbol
> >  ........  ............  ............  ........................  ........................
> > 
> >      4.13%             1  1759          Uncached hit              [k] ahci_scr_read
> >      1.16%             1  492           L1 hit                    [k] _raw_read_lock
> > 
> > (cpu groups) perf mem report --group-sort=cpu --percent-limit=1.0 --stdio
> > 
> >  Overhead       Samples  CPU
> >   Local Weight             Memory access                                      Symbol
> >  ........  ............  ............  ........................  ........................
> > 
> >     28.80%          1239   25
> > 	     3.07%               377           L1 hit                    [k] complete_walk
> > 	     2.76%               339           LFB hit                   [k] update_cfs_shares
> > 	     2.66%               326           LFB hit                   [k] copy_user_enhanced_f
> > 	     2.11%               259           Local RAM hit             [k] copy_user_enhanced_f
> > 	     1.84%               226           LFB hit                   [k] copy_user_enhanced_f
> > 	     1.74%               213           LFB hit                   [k] copy_user_enhanced_f
> > 	     1.53%               187           LFB hit                   [k] copy_user_enhanced_f
> > 	     1.04%               128           LFB hit                   [k] copy_user_enhanced_f
> > 	     1.01%               124           LFB hit                   [k] copy_user_enhanced_f
> >     27.44%           990    7
> > 	    15.06%               1759          Uncached hit              [k] ahci_scr_read
> > 	     4.21%               492           L1 hit                    [k] _raw_read_lock
> > 	     1.04%               122           LFB hit                   [k] find_busiest_group
> > 	     1.02%            1  7             L1 hit                    [.] __gconv_transform_ut
> >     20.34%          1010    0
> > 	     4.04%            5  7             L1 hit                    [k] poll_idle
> > 	     3.56%               308           Local RAM hit             [k] copy_user_enhanced_f
> > 	     2.59%               224           L3 hit                    [k] copy_user_enhanced_f
> > 	     2.12%               184           Local RAM hit             [k] copy_user_enhanced_f
> > 	     1.54%            1  7             L1 hit                    [.] __gconv_transform_ut
> 
> nice, that looks very usefull
> 
> Correct me if I'm wrong, but your current design allows to define
> just one group, right?
> 
> so, current code can do following CPU sorting:
> 
>    Overhead   CPU
>    ........   ...
>    90%        0
>    10%        1
> 
> 
> and with your changes we could do:
> 
>    Overhead   CPU  symbol
>    ........   ...  ......
>    90%        0
>         50%        krava1
>         20%        krava2
>         30%        krava3
> 
>    10%        1
>         50%        krava4
>         50%        krava5
>   
> 
> I wonder we could go more generic and allow more nested groups,
> like eg allow group sort on cpu and pid (or more):
> 
>    Overhead   CPU  pid  symbol
>    ........   ...  ...  ......
>    90%        0
>       50%          100
>         50%             krava1
>         20%             krava2
>         30%             krava3
>       50%          110
>         50%             krava1
>         20%             krava2
>         30%             krava3
> 
>    10%        1
>       100%         200
>         50%             krava4
>         50%             krava5
> 
> 
> I glanced over the changes and I wonder we could do it
> by chaining hists structs via 'struct hist_entry'
> 
> like adding 'struct hists' into 'struct hists_entry'
> and making the sort_order local for each 'struct hists'

Unless you meant:

hists
 \- hist_entry
      \- hists
           \- hist_entry -> hist_entry -> hist_entry -> hist_entry
                              \- hists
                                   \- hist_entry -> hist_entry -> hist_entry

where each 'hists' represents a new group and a hist_entry->hists != NULL
is a group otherwise just a node?

Cheers,
Don