| Message ID | 20210723124611.3828908-6-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: TRBE and Self-Hosted trace fixes | expand |
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);
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
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; }
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(-)