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* [PATCH] coresight: tmc-etr: Fix perf_data check.
@ 2019-08-09 20:23 ` Yabin Cui
  0 siblings, 0 replies; 4+ messages in thread
From: Yabin Cui @ 2019-08-09 20:23 UTC (permalink / raw)
  To: Mathieu Poirier, Suzuki K Poulose, Alexander Shishkin
  Cc: linux-arm-kernel, linux-kernel, Yabin Cui

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.

Signed-off-by: Yabin Cui <yabinc@google.com>
---
 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;
 
 	/*
 	 * No HW configuration is needed if the sink is already in
-- 
2.23.0.rc1.153.gdeed80330f-goog


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH] coresight: tmc-etr: Fix perf_data check.
@ 2019-08-09 20:23 ` Yabin Cui
  0 siblings, 0 replies; 4+ messages in thread
From: Yabin Cui @ 2019-08-09 20:23 UTC (permalink / raw)
  To: Mathieu Poirier, Suzuki K Poulose, Alexander Shishkin
  Cc: Yabin Cui, linux-kernel, linux-arm-kernel

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.

Signed-off-by: Yabin Cui <yabinc@google.com>
---
 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;
 
 	/*
 	 * No HW configuration is needed if the sink is already in
-- 
2.23.0.rc1.153.gdeed80330f-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] coresight: tmc-etr: Fix perf_data check.
  2019-08-09 20:23 ` Yabin Cui
@ 2019-08-12 10:45   ` Suzuki K Poulose
  -1 siblings, 0 replies; 4+ messages in thread
From: Suzuki K Poulose @ 2019-08-12 10:45 UTC (permalink / raw)
  To: yabinc, mathieu.poirier, alexander.shishkin
  Cc: linux-arm-kernel, linux-kernel



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 <yabinc@google.com>
> ---
>   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 <suzuki.poulose@arm.com>

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] coresight: tmc-etr: Fix perf_data check.
@ 2019-08-12 10:45   ` Suzuki K Poulose
  0 siblings, 0 replies; 4+ messages in thread
From: Suzuki K Poulose @ 2019-08-12 10:45 UTC (permalink / raw)
  To: yabinc, mathieu.poirier, alexander.shishkin
  Cc: linux-kernel, linux-arm-kernel



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 <yabinc@google.com>
> ---
>   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 <suzuki.poulose@arm.com>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-08-12 10:45 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-08-09 20:23 [PATCH] coresight: tmc-etr: Fix perf_data check Yabin Cui
2019-08-09 20:23 ` Yabin Cui
2019-08-12 10:45 ` Suzuki K Poulose
2019-08-12 10:45   ` Suzuki K Poulose

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