Re: [PATCH 4/4] perf tools: Use sw counter only if hw pmu is notdetected

From: David Ahern
Date: Thu Apr 05 2012 - 12:59:08 EST


On 4/5/12 10:26 AM, Robert Richter wrote:
Use cpu-clock-tick sw counter for cpu-cycles only if there is no hw
pmu available. This is the case if the syscall reports ENOENT. In
other cases (e.g. invalid attributes) we don't want the sw counter to
be used.

Isn't the invalid attributes case handled by the
'} else if (err == EINVAL) {'
case before this switch is done?

David



Signed-off-by: Robert Richter<robert.richter@xxxxxxx>
---
tools/perf/builtin-record.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index be4e1ee..10b1f1f 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -245,7 +245,7 @@ try_again:
* based cpu-clock-tick sw counter, which
* is always available even if no PMU support:
*/
- if (attr->type == PERF_TYPE_HARDWARE
+ if (err == ENOENT&& attr->type == PERF_TYPE_HARDWARE
&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {

if (verbose)

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