Change the driver stats to what they really are: unsigned values.

When pmcstat exits after some samples were dropped, give the user an
idea of how many were lost. (Granted, these are global numbers, but
they may still help quantify the scope of the loss.)

Differential Revision:	https://reviews.freebsd.org/D4123
Approved by:	gnn (mentor)
MFC after:	1 month
Sponsored by:	Juniper Networks

1 files changed, 14 insertions, 4 deletions

diff --git a/usr.sbin/pmcstat/pmcstat.c b/usr.sbin/pmcstat/pmcstat.c
index 914fc17..e75b937 100644
--- a/usr.sbin/pmcstat/pmcstat.c
+++ b/usr.sbin/pmcstat/pmcstat.c
@@ -1500,14 +1500,24 @@ main(int argc, char **argv)
 			    "ERROR: Cannot retrieve driver statistics");
 		if (ds_start.pm_intr_bufferfull != ds_end.pm_intr_bufferfull &&
 		    args.pa_verbosity > 0)
-			warnx("WARNING: some samples were dropped.\n"
-"Please consider tuning the \"kern.hwpmc.nsamples\" tunable."
+			warnx(
+"WARNING: sampling was paused at least %u time%s.\n"
+"Please consider tuning the \"kern.hwpmc.nsamples\" tunable.",
+			    ds_end.pm_intr_bufferfull -
+			    ds_start.pm_intr_bufferfull,
+			    ((ds_end.pm_intr_bufferfull -
+			    ds_start.pm_intr_bufferfull) != 1) ? "s" : ""
 			    );
 		if (ds_start.pm_buffer_requests_failed !=
 		    ds_end.pm_buffer_requests_failed &&
 		    args.pa_verbosity > 0)
-			warnx("WARNING: some events were discarded.\n"
-"Please consider tuning the \"kern.hwpmc.nbuffers\" tunable."
+			warnx(
+"WARNING: at least %u event%s were discarded while running.\n"
+"Please consider tuning the \"kern.hwpmc.nbuffers\" tunable.",
+	 		    ds_end.pm_buffer_requests_failed -
+			    ds_start.pm_buffer_requests_failed,
+			    ((ds_end.pm_buffer_requests_failed -
+			    ds_start.pm_buffer_requests_failed) != 1) ? "s" : ""
 			    );
 	}