Hi Daniel,
On Tue, Jul 13, 2021 at 02:15:30PM +0200, Daniel Kiss wrote:
Keep track of the perf handler that is registred by the first tracer. This will be used by the update call from polling.
Signed-off-by: Daniel Kiss daniel.kiss@arm.com Signed-off-by: Branislav Rankov Branislav.Rankov@arm.com
drivers/hwtracing/coresight/coresight-tmc-etr.c | 6 ++++-- drivers/hwtracing/coresight/coresight-tmc.h | 2 ++ 2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 589bb2d56e802..55c9b5fd9f832 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1503,8 +1503,8 @@ tmc_update_etr_buffer(struct coresight_device *csdev, spin_lock_irqsave(&drvdata->spinlock, flags);
- /* Don't do anything if another tracer is using this sink */
- if (atomic_read(csdev->refcnt) != 1) {
- /* Serve only the tracer with the leading perf handler */
- if (drvdata->perf_handle != handle) {
In CPU wide trace scenarios the first CPU to enable a sink is not guaranteed to be the same as the last CPU to use it. As far as I understand the above assumes the first and last CPUs to use a sink are the same.
spin_unlock_irqrestore(&drvdata->spinlock, flags); goto out;} @@ -1619,6 +1619,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data) drvdata->pid = pid; drvdata->mode = CS_MODE_PERF; drvdata->perf_buf = etr_perf->etr_buf;
drvdata->perf_handle = handle;@@ -1666,6 +1667,7 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev) drvdata->mode = CS_MODE_DISABLED; /* Reset perf specific data */ drvdata->perf_buf = NULL;
- drvdata->perf_handle = NULL;
spin_unlock_irqrestore(&drvdata->spinlock, flags); diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index b91ec7dde7bc9..81583ffb973dc 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -184,6 +184,7 @@ struct etr_buf {
- @idr_mutex: Access serialisation for idr.
- @sysfs_buf: SYSFS buffer for ETR.
- @perf_buf: PERF buffer for ETR.
*/
- @perf_handle: PERF handle for ETR.
struct tmc_drvdata { void __iomem *base; @@ -207,6 +208,7 @@ struct tmc_drvdata { struct mutex idr_mutex; struct etr_buf *sysfs_buf; struct etr_buf *perf_buf;
- struct perf_output_handle *perf_handle;
}; struct etr_buf_operations { -- 2.25.1