Re: [PATCH v2 05/10] coresight: trbe: Drop duplicate TRUNCATE flags
From: Anshuman Khandual <hidden>
Date: 2021-07-30 04:46:42
Also in:
lkml
On 7/23/21 6:16 PM, Suzuki K Poulose wrote:
quoted hunk ↗ jump to hunk
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 <redacted> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <redacted> Cc: Leo Yan <redacted> 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);
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