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authorJiri Olsa <jolsa@redhat.com>2011-06-01 21:43:46 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-08-11 08:58:03 -0300
commitf57b05ed532ccf3b3e22878a5678ca10de50ad29 (patch)
tree97fed90fc6181939af5a29dfc9624163832b34e6 /tools/perf/util/header.c
parentfc8ed7be738ffb1b3b0140ed2de6def38b9a7101 (diff)
perf report: Use properly build_id kernel binaries
If we bring the recorded perf data together with kernel binary from another machine using: on server A: perf archive on server B: tar xjvf perf.data.tar.bz2 -C ~/.debug the build_id kernel dso is not properly recognized during the "perf report" command on server B. The reason is, that build_id dsos are added during the session initialization, while the kernel maps are created during the sample event processing. The machine__create_kernel_maps functions ends up creating new dso object for kernel, but it does not check if we already have one added by build_id processing. Also the build_id reading ABI quirk added in commit: - commit b25114817a73bbd2b84ce9dba02ee1ef8989a947 perf build-id: Add quirk to deal with perf.data file format breakage populates the "struct build_id_event::pid" with 0, which is later interpreted as DEFAULT_GUEST_KERNEL_ID. This is not always correct, so it's better to guess the pid value based on the "struct build_id_event::header::misc" value. - Tested with data generated on x86 kernel version v2.6.34 and reported back on x86_64 current kernel. - Not tested for guest kernel case. Note the problem stays for PERF_RECORD_MMAP events recorded by perf that does not use proper pid (HOST_KERNEL_ID/DEFAULT_GUEST_KERNEL_ID). They are misinterpreted within the current perf code. Probably there's not much we can do about that. Cc: Avi Kivity <avi@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Link: http://lkml.kernel.org/r/20110601194346.GB1934@jolsa.brq.redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/header.c')
-rw-r--r--tools/perf/util/header.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index d4f3101773d..b6c1ad123ca 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -726,7 +726,16 @@ static int perf_header__read_build_ids_abi_quirk(struct perf_header *header,
return -1;
bev.header = old_bev.header;
- bev.pid = 0;
+
+ /*
+ * As the pid is the missing value, we need to fill
+ * it properly. The header.misc value give us nice hint.
+ */
+ bev.pid = HOST_KERNEL_ID;
+ if (bev.header.misc == PERF_RECORD_MISC_GUEST_USER ||
+ bev.header.misc == PERF_RECORD_MISC_GUEST_KERNEL)
+ bev.pid = DEFAULT_GUEST_KERNEL_ID;
+
memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
__event_process_build_id(&bev, filename, session);