Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes

[Wangnan (F)]

On 2015/12/11 10:42, Wangnan (F) wrote:
> On 2015/12/11 10:15, åæéå / HIRAMATUïMASAMI wrote:
> > From: 'Arnaldo Carvalho de Melo' [mailto:acme@xxxxxxxxxx]
> > > But this requires having these special refcnt__ routines, that will 
> > > make
> > > tools/perf/ code patterns for reference counts look different that the
> > > refcount patterns in the kernel :-\
> > BTW, I think even without the refcnt debugger, we'd better introduce 
> > this
> > kind API to unify the refcnt operation in perf code. As I said, we 
> > have many
> > miscodings on current implementation. Unifying the API can enforce 
> > developers
> > to avoid such miscodings.
> >
> > Thank you,
>
> I tried this problem in another way, I'd like to share it here.
>
> First: create two uprobes:
>
> # ./perf probe --exec /home/wangnan/perf dso__new%return %ax
> Added new event:
>   probe_perf:dso__new  (on dso__new%return in /home/wangnan/perf with 
> %ax)
>
> You can now use it in all perf tools, such as:
>
>     perf record -e probe_perf:dso__new -aR sleep 1
>
> # ./perf probe --exec /home/wangnan/perf dso__delete dso
> Added new event:
>   probe_perf:dso__delete (on dso__delete in /home/wangnan/perf with dso)
>
> You can now use it in all perf tools, such as:
>
>     perf record -e probe_perf:dso__delete -aR sleep 1
>
>
> Then start test:
>
> # ./perf record -g -e probe_perf:dso__new -e probe_perf:dso__delete 
> ./perf probe vfs_read
> Added new event:
>   probe:vfs_read       (on vfs_read)
>
> You can now use it in all perf tools, such as:
>
>     perf record -e probe:vfs_read -aR sleep 1
>
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.048 MB perf.data (178 samples) ]
>
>
> From the perf report result I know two dso objects are leak:
>
> 90 probe_perf:dso__new `
> 88 probe_perf:dso__delete

The above result is gotten from yesterday's perf/core. I also tried
today's perf/core and get:

90 probe_perf:dso__new `
90 probe_perf:dso__delete

So we fix these leak.

Thank you.

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