Linux 4.2 reserved a new bit from the misc field in the perf_event_open mmap sample buffer: PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT Despite being reserved in the public include/uapi/linux/perf_event.h header file, this bit is never set by the kernel, rather it is used internally by the userspace "perf" utility to indicate that when attempting to parse all of the /proc/xxx/maps files for the sample it ended up taking too long so the scan was aborted. Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 index fa8b1bd..59ad289 100644 --- a/man2/perf_event_open.2 +++ b/man2/perf_event_open.2 @@ -1822,6 +1822,14 @@ See also .BR PERF_RECORD_MISC_EXT_RESERVED " (since Linux 2.6.35)" .\" commit 1676b8a077c352085d52578fb4f29350b58b6e74 This indicates there is extended data available (currently not used). +.TP +.B PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT +.\" commit 930e6fcd2bcce9bcd9d4aa7e755678d33f3fe6f4 +This bit is not set by the kernel. +It is reserved for the userspace perf utility to indicate that +.I /proc/xxx/maps +parsing was taking too long and stopped and thus the mmap +records may be truncated. .RE .TP .I type -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
