On 30/07/2021 05:47, Anshuman Khandual wrote:

On 7/23/21 6:16 PM, Suzuki K Poulose wrote:

...

We mark the buffer as TRUNCATED when there is no space left in the buffer. But we do it at different points. __trbe_normal_offset() and also, at all the callers of the above function via compute_trbe_buffer_limit(), when the limit == base (i.e offset = 0 as returned by the __trbe_normal_offset()).

So, given that the callers already mark the buffer as TRUNCATED drop the caller inside the __trbe_normal_offset().

This is in preparation to moving the handling of TRUNCATED into a central place.

Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Mike Leach mike.leach@linaro.org Cc: Leo Yan leo.yan@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com

---

drivers/hwtracing/coresight/coresight-trbe.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 446f080f8320..62e1a08f73ff 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -253,13 +253,9 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle) * trbe_base trbe_base + nr_pages * * Perf aux buffer does not have any space for the driver to write into.

• * Just communicate trace truncation event to the user space by marking
  

• * it with PERF_AUX_FLAG_TRUNCATED.
  

  */
• if (!handle->size) {

• perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
  

• if (!handle->size) return 0;

• }

/* Compute the tail and wakeup indices now that we've aligned head */ tail = PERF_IDX2OFF(handle->head + handle->size, buf); @@ -361,7 +357,6 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle) return limit; trbe_pad_buf(handle, handle->size);

• perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); return 0; }

What about in trbe_handle_spurious() path which used to set the flag via compute_trbe_buffer_limit(), but would not any more after this change. I guess following additional change would be required to preserve the past behaviour.

--- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -685,6 +685,7 @@ static void trbe_handle_spurious(struct perf_output_handle *handle) buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf); if (buf->trbe_limit == buf->trbe_base) { trbe_drain_and_disable_local();

•           perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
             return;
     }
     trbe_enable_hw(buf);
  
  

Agreed, I will add this.

Thanks Suzuki