Optionally produce stats on syscall latency
Time spent in system time is not useful where a syscall depends on some
non-CPU resource, eg. typically open() or stat() to a network drive.
This patch adds a new flag (-w) to produce a summary of the time
difference between beginning and end of the system call (ie. latency)
This functionality has been useful to profile slow processes that
are not CPU-bound.
Signed-off-by: Mark Hills <mark.hills@framestore.com>
diff --git a/strace.1 b/strace.1
index 6ca4bda..4d26be5 100644
--- a/strace.1
+++ b/strace.1
@@ -290,6 +290,10 @@
Show the time spent in system calls. This records the time
difference between the beginning and the end of each system call.
.TP
+.B \-w
+Summarise the time difference between the beginning and end of
+each system call. The default is to summarise the system time.
+.TP
.B \-v
Print unabbreviated versions of environment, stat, termios, etc.
calls. These structures are very common in calls and so the default