From 4f8f382e635707ddaddf8269a116e4f8cc8835c0 Mon Sep 17 00:00:00 2001 From: David Miller Date: Tue, 30 Oct 2018 22:24:04 -0700 Subject: perf tools: Don't clone maps from parent when synthesizing forks When synthesizing FORK events, we are trying to create thread objects for the already running tasks on the machine. Normally, for a kernel FORK event, we want to clone the parent's maps because that is what the kernel just did. But when synthesizing, this should not be done. If we do, we end up with overlapping maps as we process the sythesized MMAP2 events that get delivered shortly thereafter. Use the FORK event misc flags in an internal way to signal this situation, so we can elide the map clone when appropriate. Signed-off-by: David S. Miller Cc: Don Zickus Cc: Jiri Olsa Cc: Joe Mario Link: http://lkml.kernel.org/r/20181030.222404.2085088822877051075.davem@davemloft.net [ Added comment about flag use in machine__process_fork_event(), use ternary op in thread__clone_map_groups() as suggested by Jiri ] Signed-off-by: Arnaldo Carvalho de Melo --- include/uapi/linux/perf_event.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index f35eb72739c0..9de8780ac8d9 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -646,10 +646,12 @@ struct perf_event_mmap_page { * * PERF_RECORD_MISC_MMAP_DATA - PERF_RECORD_MMAP* events * PERF_RECORD_MISC_COMM_EXEC - PERF_RECORD_COMM event + * PERF_RECORD_MISC_FORK_EXEC - PERF_RECORD_FORK event (perf internal) * PERF_RECORD_MISC_SWITCH_OUT - PERF_RECORD_SWITCH* events */ #define PERF_RECORD_MISC_MMAP_DATA (1 << 13) #define PERF_RECORD_MISC_COMM_EXEC (1 << 13) +#define PERF_RECORD_MISC_FORK_EXEC (1 << 13) #define PERF_RECORD_MISC_SWITCH_OUT (1 << 13) /* * These PERF_RECORD_MISC_* flags below are safely reused -- cgit v1.2.3