From: Frederic Weisbecker <fweisbec@gmail.com>
To: Nick Piggin <npiggin@kernel.dk>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: buggy perf callgraph output
Date: Wed, 8 Dec 2010 22:48:13 +0100 [thread overview]
Message-ID: <20101208214809.GG1709@nowhere> (raw)
In-Reply-To: <20101208164015.GA5444@amd>
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.
next prev parent reply other threads:[~2010-12-08 21:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-08 16:40 buggy perf callgraph output Nick Piggin
2010-12-08 21:48 ` Frederic Weisbecker [this message]
2010-12-15 13:02 ` Nick Piggin
2010-12-16 11:47 ` Frederic Weisbecker
2010-12-17 5:32 ` Nick Piggin
2010-12-23 12:55 ` Frederic Weisbecker
2010-12-23 13:08 ` Ingo Molnar
2010-12-23 13:35 ` Frederic Weisbecker
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