On 09/08/2019 21:23, Yabin Cui wrote:
When tracing etm data of multiple threads on multiple cpus through
perf interface, each cpu has a unique etr_perf_buffer while sharing
the same etr device. There is no guarantee that the last cpu starts
etm tracing also stops last. This makes perf_data check fail.
Fix it by checking etr_buf instead of etr_perf_buffer.
Please could you add a Fixes tag for this:
Fixes: 3147da92a8a81fc3 ("coresight: tmc-etr: Allocate and free ETR memory
buffers for CPU-wide scenarios")
as the problem was introduced as a side effect of the above patch ?
Signed-off-by: Yabin Cui <[email protected]>
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c
b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 17006705287a..f466f05afe08 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1484,7 +1484,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
goto out;
}
- if (WARN_ON(drvdata->perf_data != etr_perf)) {
+ if (WARN_ON(drvdata->perf_data != etr_buf)) {
lost = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
goto out;
@@ -1556,7 +1556,7 @@ static int tmc_enable_etr_sink_perf(struct
coresight_device *csdev, void *data)
}
etr_perf->head = PERF_IDX2OFF(handle->head, etr_perf);
- drvdata->perf_data = etr_perf;
+ drvdata->perf_data = etr_perf->etr_buf;
minor nit: Now that we are storing the etr_buf instead of the etr_perf_buf in
perf_data, we could make the "perf_data" => "perf_buf" inline with the
sysfs_buf.
Either ways:
Reviewed-by: Suzuki K Poulose <[email protected]>
