Re: [PATCH 1/3] perf, tool: Force guest machine definition option
From: Jiri Olsa
Date: Sun Apr 15 2012 - 10:06:06 EST
On Fri, Apr 13, 2012 at 08:15:17AM -0600, David Ahern wrote:
> On 4/13/12 6:41 AM, Jiri Olsa wrote:
> >I get same error even on acme's urgent branch.. do you mean
> >below one? It fixes the guest machine lookup for mmap event.
> >
> >perf kvm: Finding struct machine fails for PERF_RECORD_MMAP
> >commit 7fb0a5ee8889488f7568ffddffeb66ddeb50917e
> >Author: Nikunj A. Dadhania<nikunj@xxxxxxxxxxxxxxxxxx>
> >Date: Mon Apr 9 13:52:23 2012 +0530
>
> That's the one I was referring to.
>
> >
> >In my case it looks like for some reason the guest buildid DSO
> >is not stored in record phase (no hits maybe?), so report won't
> >create guest machine record at all and get NULL machine.
>
> I see now -- different problem, but similar in that it's an mmap
> event and the pid is 0.
>
> I need to take my daughter to school and won't get back to this for
> a while but what I am seeing is that on perf-record mmap events are
> generated with pid set to DEFAULT_GUEST_KERNEL_ID = 0
> (machines__create_guest_kernel_maps).
>
> On the report side a machine has not been created for pid of 0, so
> the look up in perf_session__find_machine_for_cpumode fails.
>
> David
how about the patch below? it ensures there's machine record for
the guest. The segfault issue still stays..
jirka
---
Running 'perf kvm record' without any of following options:
--guestmount
--guestvmlinux
--guestkallsyms
--guestmodules
is causing the guest machine to be ommited from the data file,
and all guest samples are counted in nr_unprocessable_samples.
This patch makes sure the 'perf kvm record' command is not
let through if guest machine isn't defined.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 10b1f1f..0ae4237 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -462,6 +462,14 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
return -1;
}
+ if (perf_guest &&
+ !machines__find(&session->machines, DEFAULT_GUEST_KERNEL_ID)) {
+ ui__warning("You need to define guest with one of guestmount|"
+ "guestvmlinux|guestkallsyms|guestmodules\n");
+ err = -EINVAL;
+ goto out_delete_session;
+ }
+
rec->session = session;
for (feat = HEADER_FIRST_FEATURE; feat < HEADER_LAST_FEATURE; feat++)
--
1.7.7.6
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