From 2f335a02b3c816e77e7df1d15b12e3bbb8f4c8f0 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 5 Jun 2009 19:31:01 +0200
Subject: [PATCH] perf top: Fix zero or negative refresh delay
If perf top is executed with a zero value for the refresh rate,
we get a division by zero exception while computing samples_per_sec.
Also a zero refresh rate is not possible, neither do we want to
accept negative values.
[ Impact: fix division by zero in perf top ]
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1244223061-5399-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
Documentation/perf_counter/builtin-top.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/perf_counter/builtin-top.c b/Documentation/perf_counter/builtin-top.c
index ff7e13c4647c..b2f480b5a134 100644
--- a/Documentation/perf_counter/builtin-top.c
+++ b/Documentation/perf_counter/builtin-top.c
@@ -693,6 +693,9 @@ int cmd_top(int argc, const char **argv, const char *prefix)
event_id[0] = 0;
}
+ if (delay_secs < 1)
+ delay_secs = 1;
+
for (counter = 0; counter < nr_counters; counter++) {
if (event_count[counter])
continue;
--
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