Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 8 Dec 2010 22:48:13 +0100 | From | Frederic Weisbecker <> | Subject | Re: buggy perf callgraph output |
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On Thu, Dec 09, 2010 at 03:40:15AM +1100, Nick Piggin wrote: > Hi, > > I get strange looking perf output with the callchain hits not sorted > properly for graph and fractal: > > 7.34% open [kernel.kallsyms] [k] kmem_cache_alloc > | > --- kmem_cache_alloc > | > |---0.05%-- get_empty_filp > | do_filp_open > | do_sys_open > | sys_open > | system_call > | __open_nocancel > | > ---0.16%-- getname > do_sys_open > sys_open > system_call > __open_nocancel > > 6.17% open [kernel.kallsyms] [k] _raw_spin_lock > | > --- _raw_spin_lock > | > |---0.01%-- add_partial > | __slab_free > | kmem_cache_free > | file_free_rcu > | __rcu_process_callbacks > | rcu_process_callbacks > | __do_softirq > | call_softirq > | do_softirq > | irq_exit > | smp_apic_timer_interrupt > | apic_timer_interrupt > | > |---0.16%-- dput > | | > | --0.57%-- fput > | filp_close > | sys_close > | system_call > | __libc_close > | > |--0.60%-- link_path_walk > | do_path_lookup > | do_filp_open > | do_sys_open > | sys_open > | system_call > | __open_nocancel > | > |--0.57%-- __slab_free > | kmem_cache_free > | file_free_rcu > | __rcu_process_callbacks > | rcu_process_callbacks > | __do_softirq > > > With flat it looks a bit better: > 7.34% open [kernel.kallsyms] [k] kmem_cache_alloc > 6.09% > kmem_cache_alloc > get_empty_filp > do_filp_open > do_sys_open > sys_open > system_call > __open_nocancel > > 1.07% > kmem_cache_alloc > getname > do_sys_open > sys_open > system_call > __open_nocancel > > 6.17% open [kernel.kallsyms] [k] _raw_spin_lock > 0.60% > _raw_spin_lock > link_path_walk > do_path_lookup > do_filp_open > do_sys_open > sys_open > system_call > __open_nocancel > > 0.57% > _raw_spin_lock > fd_install > do_sys_open > sys_open > system_call > __open_nocancel > > 0.57% > _raw_spin_lock > dput > fput > filp_close > sys_close > system_call > __libc_close
I can not reproduce it. Could you please try to reproduce, run perf archive and send me your perf.data.tar.bz2 ?
Thanks.
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