From: Simon Kaempflein <s.kaempflein@gmx.de>
Date: Mon, 16 Nov 2009 05:25:53 +0000 (+1000)
Subject: perf record, x86: Print more intelligent error message when sampling fails
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=bfd451184d80301d1ae970b1ebffde1e9c6240f9;p=openwrt%2Fstaging%2Fblogic.git

perf record, x86: Print more intelligent error message when sampling fails

Print more accurate error message when "perf record" fails because
there is no APIC support, on x86.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 87f98fdb0513..0e519c667e3a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -307,6 +307,12 @@ try_again:
 		printf("\n");
 		error("perfcounter syscall returned with %d (%s)\n",
 			fd[nr_cpu][counter], strerror(err));
+
+#if defined(__i386__) || defined(__x86_64__)
+		if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
+			die("No hardware sampling interrupt available. No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.\n");
+#endif
+
 		die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 		exit(-1);
 	}