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From: Vince Weaver <vincent.weaver@maine.edu>
To: Dave Jones <davej@redhat.com>
Cc: trinity@vger.kernel.org
Subject: [patch] perf_event_open more likely tracepoint values
Date: Thu, 14 Nov 2013 12:35:27 -0500 (EST)	[thread overview]
Message-ID: <alpine.DEB.2.10.1311141230450.8746@vincent-weaver-1.um.maine.edu> (raw)


Tracepoint ids tend to be relatively small (less than 1024 or so).
This change makes it more likely to hit valid ones.

Once the fix to avoid the troublesome 0x18 (irq_work_exit)
tracepoint gets into the kernel maybe we can start stressing
things with trinity again.

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>


diff --git a/syscalls/perf_event_open.c b/syscalls/perf_event_open.c
index 2ff004e..516172a 100644
--- a/syscalls/perf_event_open.c
+++ b/syscalls/perf_event_open.c
@@ -723,9 +723,20 @@ static long long random_event_config(__u32 *event_type,
 		break;
 	case PERF_TYPE_TRACEPOINT:
 		/* Actual values to use can be found under */
-		/* debugfs tracing/events// *//*/id        */
-		/* usually a small < 1024 number           */
-		config = rand64();
+		/* debugfs tracing/events/?*?/?*?/id       */
+		/* usually a small < 4096 number           */
+		switch(rand()%2) {
+		case 0:
+			/* Try a value < 4096 */
+			config = rand()&0xfff;
+			break;
+		case 1:
+			config = rand64();
+			break;
+		default:
+			config = rand64();
+			break;
+		}
 		break;
 	case PERF_TYPE_HW_CACHE:
 		config = random_cache_config();

next             reply	other threads:[~2013-11-14 17:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-14 17:35 Vince Weaver [this message]
2013-11-14 17:33 ` [patch] perf_event_open more likely tracepoint values Dave Jones
2013-11-15 20:45   ` Vince Weaver

find likely ancestor, descendant, or conflicting patches for this message:
dfblob:2ff004e dfblob:516172a
	(help)

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