| Message ID | 20230809081825.11518-4-yangyicong@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Several updates for PTT driver | expand |
On Wed, 9 Aug 2023 16:18:23 +0800 Yicong Yang <yangyicong@huawei.com> wrote: > From: Yicong Yang <yangyicong@hisilicon.com> > > Currently during the PTT trace, we'll only commit the data > to the perf core when its full, which means after 4 interrupts > and totally 16MiB data while the AUX buffer is 16MiB length. > Then the userspace gets notified and handle the data. The driver > cannot apply a new AUX buffer immediately until the committed data > are handled and there's enough room in the buffer again. > > This patch tries to optimize this by commit the data in every > interrupts in a 4MiB granularity. Then the userspace can have > enough time to consume the data and there's always enough room > in the AUX buffer. > > Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > drivers/hwtracing/ptt/hisi_ptt.c | 15 +++++++-------- > 1 file changed, 7 insertions(+), 8 deletions(-) > > diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c > index 89638ed96cf9..3aba7bb6e548 100644 > --- a/drivers/hwtracing/ptt/hisi_ptt.c > +++ b/drivers/hwtracing/ptt/hisi_ptt.c > @@ -274,15 +274,14 @@ static int hisi_ptt_update_aux(struct hisi_ptt *hisi_ptt, int index, bool stop) > buf->pos += size; > > /* > - * Just commit the traced data if we're going to stop. Otherwise if the > - * resident AUX buffer cannot contain the data of next trace buffer, > - * apply a new one. > + * Always commit the data to the AUX buffer in time to make sure > + * userspace got enough time to consume the data. > + * > + * If we're not going to stop, apply a new one and check whether > + * there's enough room for the next trace. > */ > - if (stop) { > - perf_aux_output_end(handle, buf->pos); > - } else if (buf->length - buf->pos < HISI_PTT_TRACE_BUF_SIZE) { > - perf_aux_output_end(handle, buf->pos); > - > + perf_aux_output_end(handle, size); > + if (!stop) { > buf = perf_aux_output_begin(handle, event); > if (!buf) > return -EINVAL;
diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index 89638ed96cf9..3aba7bb6e548 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -274,15 +274,14 @@ static int hisi_ptt_update_aux(struct hisi_ptt *hisi_ptt, int index, bool stop) buf->pos += size; /* - * Just commit the traced data if we're going to stop. Otherwise if the - * resident AUX buffer cannot contain the data of next trace buffer, - * apply a new one. + * Always commit the data to the AUX buffer in time to make sure + * userspace got enough time to consume the data. + * + * If we're not going to stop, apply a new one and check whether + * there's enough room for the next trace. */ - if (stop) { - perf_aux_output_end(handle, buf->pos); - } else if (buf->length - buf->pos < HISI_PTT_TRACE_BUF_SIZE) { - perf_aux_output_end(handle, buf->pos); - + perf_aux_output_end(handle, size); + if (!stop) { buf = perf_aux_output_begin(handle, event); if (!buf) return -EINVAL;