From: Jiri Olsa <jolsa@redhat.com>
To: David Ahern <dsahern@gmail.com>
Cc: acme@ghostprotocols.net, linux-kernel@vger.kernel.org,
Ingo Molnar <mingo@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 04/11] perf kvm: fix bug resolving guest kernel syms - v2
Date: Wed, 25 Jul 2012 14:11:21 +0200 [thread overview]
Message-ID: <20120725121121.GB946@krava.brq.redhat.com> (raw)
In-Reply-To: <1342826756-64663-5-git-send-email-dsahern@gmail.com>
On Fri, Jul 20, 2012 at 05:25:49PM -0600, David Ahern wrote:
> Guest kernel symbols are not resolved despite passing the information
> needed to resolve them. e.g.,
>
> perf kvm --guest --guestmount=/tmp/guest-mount record -a -- sleep 1
> perf kvm --guest --guestmount=/tmp/guest-mount report --stdio
>
> 36.55% [guest/11399] [unknown] [g] 0xffffffff81600bc8
> 33.19% [guest/10474] [unknown] [g] 0x00000000c0116e00
> 30.26% [guest/11094] [unknown] [g] 0xffffffff8100a288
> 43.69% [guest/10474] [unknown] [g] 0x00000000c0103d90
> 37.38% [guest/11399] [unknown] [g] 0xffffffff81600bc8
> 12.24% [guest/11094] [unknown] [g] 0xffffffff810aa91d
> 6.69% [guest/11094] [unknown] [u] 0x00007fa784d721c3
>
> which is just pathetic.
>
> After a maddening 2 days sifting through perf minutia I found it --
> id_hdr_size is not initialized for guest machines. This shows up on the
> report side as random garbage for the cpu and timestamp, e.g.,
>
> 29816 7310572949125804849 0x1ac0 [0x50]: PERF_RECORD_MMAP ...
>
> That messes up the sample sorting such that synthesized guest maps are
> processed last.
>
> With this patch you get a much more helpful report:
>
> 12.11% [guest/11399] [guest.kernel.kallsyms.11399] [g] irqtime_account_process_tick
> 10.58% [guest/11399] [guest.kernel.kallsyms.11399] [g] run_timer_softirq
> 6.95% [guest/11094] [guest.kernel.kallsyms.11094] [g] printk_needs_cpu
> 6.50% [guest/11094] [guest.kernel.kallsyms.11094] [g] do_timer
> 6.45% [guest/11399] [guest.kernel.kallsyms.11399] [g] idle_balance
> 4.90% [guest/11094] [guest.kernel.kallsyms.11094] [g] native_read_tsc
> ...
>
> v2:
> - changed rbtree walk to use rb_first per Namhyung's suggestion
>
> Signed-off-by: David Ahern <dsahern@gmail.com>
> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
next prev parent reply other threads:[~2012-07-25 12:11 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-20 23:25 [PATCH 00/11] perf tool: assorted cleanups and bug fixes David Ahern
2012-07-20 23:25 ` [PATCH 01/11] perf tool: add machine id to modules debug message David Ahern
2012-07-25 19:16 ` [tip:perf/core] perf symbols: Add " tip-bot for David Ahern
2012-07-20 23:25 ` [PATCH 02/11] perf kvm: set name for VM process in guest machine David Ahern
2012-07-25 12:12 ` Jiri Olsa
2012-07-25 19:17 ` [tip:perf/core] perf kvm: Set " tip-bot for David Ahern
2012-07-20 23:25 ` [PATCH 03/11] perf kvm: guest userspace samples should not be lumped with host uspace David Ahern
2012-07-25 12:13 ` Jiri Olsa
2012-07-25 19:18 ` [tip:perf/core] perf kvm: Guest " tip-bot for David Ahern
2012-07-20 23:25 ` [PATCH 04/11] perf kvm: fix bug resolving guest kernel syms - v2 David Ahern
2012-07-25 12:11 ` Jiri Olsa [this message]
2012-07-25 19:19 ` [tip:perf/core] perf kvm: Fix bug resolving guest kernel syms tip-bot for David Ahern
2012-07-20 23:25 ` [PATCH 05/11] perf kvm: use strtol for walking guestmount directory David Ahern
2012-07-23 18:09 ` Arnaldo Carvalho de Melo
2012-07-20 23:25 ` [PATCH 06/11] perf kvm: limit repetitive guestmount message to once per directory David Ahern
2012-07-23 18:11 ` Arnaldo Carvalho de Melo
2012-07-25 19:20 ` [tip:perf/core] perf kvm: Limit " tip-bot for David Ahern
2012-07-20 23:25 ` [PATCH 07/11] perf tools: dump exclude_{guest,host}, precise_ip header info too David Ahern
2012-07-25 19:20 ` [tip:perf/core] perf tools: Dump " tip-bot for David Ahern
2012-07-20 23:25 ` [PATCH 08/11] perf tool: precise mode requires exclude_guest David Ahern
2012-07-23 18:13 ` Arnaldo Carvalho de Melo
2012-07-24 14:20 ` David Ahern
2012-07-24 16:15 ` Robert Richter
2012-07-24 17:28 ` David Ahern
2012-07-24 18:03 ` Arnaldo Carvalho de Melo
2012-07-26 5:16 ` David Ahern
2012-07-26 8:08 ` Peter Zijlstra
2012-08-03 13:51 ` Robert Richter
2012-08-15 15:22 ` David Ahern
2012-09-05 15:43 ` David Ahern
2012-09-05 22:07 ` Peter Zijlstra
2012-09-06 17:44 ` Robert Richter
2012-09-06 18:19 ` David Ahern
2012-07-25 20:35 ` Peter Zijlstra
2012-07-26 5:50 ` Gleb Natapov
2012-07-26 8:07 ` Peter Zijlstra
2012-07-26 8:10 ` Gleb Natapov
2012-07-26 9:07 ` Robert Richter
2012-08-02 16:06 ` David Ahern
2012-09-06 19:02 ` Robert Richter
2012-09-06 19:17 ` David Ahern
2012-09-06 19:56 ` Robert Richter
2012-09-07 16:41 ` [PATCH] perf, ibs: Check syscall attribute flags Robert Richter
2012-09-07 16:50 ` David Ahern
2012-09-07 17:07 ` Robert Richter
2012-09-07 17:11 ` David Ahern
2012-09-07 17:20 ` David Ahern
2012-09-10 13:07 ` Robert Richter
2012-09-10 15:37 ` Arnaldo Carvalho de Melo
2012-09-07 17:25 ` Robert Richter
2012-09-07 16:56 ` Peter Zijlstra
2012-09-07 17:18 ` Robert Richter
2012-09-07 19:11 ` Peter Zijlstra
2012-09-10 9:30 ` [PATCH -v2] " Robert Richter
2012-09-14 6:17 ` [tip:perf/urgent] perf/x86/ibs: " tip-bot for Robert Richter
2012-07-20 23:25 ` [PATCH 09/11] perf top: error handling for counter creation should parallel perf-record David Ahern
2012-07-23 18:15 ` Arnaldo Carvalho de Melo
2012-07-24 14:01 ` David Ahern
2012-07-24 14:39 ` Arnaldo Carvalho de Melo
2012-07-20 23:25 ` [PATCH 10/11] perf tool: give user better message if precise is not supported David Ahern
2012-07-21 10:40 ` Namhyung Kim
2012-07-22 2:28 ` David Ahern
2012-07-20 23:25 ` [PATCH 11/11] perf kvm top: limit guest kernel info message to once David Ahern
2012-07-23 18:17 ` Arnaldo Carvalho de Melo
2012-07-24 14:02 ` David Ahern
2012-07-24 14:40 ` Arnaldo Carvalho de Melo
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