From adb5d2a487c55e5ca2ecc0b73c8f592e95d292c7 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 20 Jul 2012 17:25:49 -0600 Subject: perf kvm: Fix bug resolving guest kernel syms 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 Tested-by: Jiri Olsa Signed-off-by: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1342826756-64663-5-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/map.h | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/perf/util/map.h') diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h index c14c665..03a1e9b 100644 --- a/tools/perf/util/map.h +++ b/tools/perf/util/map.h @@ -151,6 +151,7 @@ struct machine *machines__add(struct rb_root *self, pid_t pid, struct machine *machines__find_host(struct rb_root *self); struct machine *machines__find(struct rb_root *self, pid_t pid); struct machine *machines__findnew(struct rb_root *self, pid_t pid); +void machines__set_id_hdr_size(struct rb_root *self, u16 id_hdr_size); char *machine__mmap_name(struct machine *self, char *bf, size_t size); int machine__init(struct machine *self, const char *root_dir, pid_t pid); void machine__exit(struct machine *self); -- cgit v1.1