| Message ID | 20210905131237.1035322-3-leo.yan@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: Fix for snapshot mode | expand |
Hi Leo On 05/09/2021 14:12, Leo Yan wrote: > Commit 2f01c200d440 ("perf cs-etm: Remove callback cs_etm_find_snapshot()") > has removed the function cs_etm_find_snapshot() from the perf tool in the > user space, now CoreSight trace directly uses the perf common function > __auxtrace_mmap__read() to calcualte the head and size for AUX trace data > in snapshot mode. > > Updates the comments in drivers to reflect the changes. As such I would avoid referencing "userspace" function names in the kernel driver. Please could we remove it or make it generic ? Also, remember, perf is not the only userspace tool driving the kernel perf. Cheers Suzuki > > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > drivers/hwtracing/coresight/coresight-etb10.c | 2 +- > drivers/hwtracing/coresight/coresight-tmc-etf.c | 2 +- > drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c > index f775cbee12b8..1cdb627d6c38 100644 > --- a/drivers/hwtracing/coresight/coresight-etb10.c > +++ b/drivers/hwtracing/coresight/coresight-etb10.c > @@ -557,7 +557,7 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev, > > /* > * In snapshot mode we simply increment the head by the number of byte > - * that were written. User space function cs_etm_find_snapshot() will > + * that were written. User space function __auxtrace_mmap__read() will > * figure out how many bytes to get from the AUX buffer based on the > * position of the head. > */ > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c > index cd0fb7bfba68..a895931a2766 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c > @@ -546,7 +546,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, > > /* > * In snapshot mode we simply increment the head by the number of byte > - * that were written. User space function cs_etm_find_snapshot() will > + * that were written. User space function __auxtrace_mmap__read() will > * figure out how many bytes to get from the AUX buffer based on the > * position of the head. > */ > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index d23c7690f29a..941abb70b827 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -1573,7 +1573,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev, > > /* > * In snapshot mode we simply increment the head by the number of byte > - * that were written. User space function cs_etm_find_snapshot() will > + * that were written. User space function __auxtrace_mmap__read() will > * figure out how many bytes to get from the AUX buffer based on the > * position of the head. > */ >
Hi Suzuki, On Mon, Sep 06, 2021 at 10:51:02AM +0100, Suzuki Kuruppassery Poulose wrote: > Hi Leo > > > On 05/09/2021 14:12, Leo Yan wrote: > > Commit 2f01c200d440 ("perf cs-etm: Remove callback cs_etm_find_snapshot()") > > has removed the function cs_etm_find_snapshot() from the perf tool in the > > user space, now CoreSight trace directly uses the perf common function > > __auxtrace_mmap__read() to calcualte the head and size for AUX trace data > > in snapshot mode. > > > > Updates the comments in drivers to reflect the changes. > > As such I would avoid referencing "userspace" function names in the > kernel driver. Please could we remove it or make it generic ? Okay, I'd like to remove the specific function name from the comment so can make the comment generic as: "User space will figure out how many bytes to get from the AUX buffer based on the position of the head." This info can remind us how the userspace and kernel co-work for snapshot mode if later we read the code. If no objection, I will respin with this way. > Also, remember, perf is not the only userspace tool driving the kernel > perf. Good point. Thanks for review, Leo
On 06/09/2021 11:28, Leo Yan wrote: > Hi Suzuki, > > On Mon, Sep 06, 2021 at 10:51:02AM +0100, Suzuki Kuruppassery Poulose wrote: >> Hi Leo >> >> >> On 05/09/2021 14:12, Leo Yan wrote: >>> Commit 2f01c200d440 ("perf cs-etm: Remove callback cs_etm_find_snapshot()") >>> has removed the function cs_etm_find_snapshot() from the perf tool in the >>> user space, now CoreSight trace directly uses the perf common function >>> __auxtrace_mmap__read() to calcualte the head and size for AUX trace data >>> in snapshot mode. >>> >>> Updates the comments in drivers to reflect the changes. >> >> As such I would avoid referencing "userspace" function names in the >> kernel driver. Please could we remove it or make it generic ? > > Okay, I'd like to remove the specific function name from the comment so > can make the comment generic as: > > "User space will figure out how many bytes to get from the AUX buffer > based on the position of the head." Yes please, that sounds perfect. Cheers Suzuki
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index f775cbee12b8..1cdb627d6c38 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -557,7 +557,7 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev, /* * In snapshot mode we simply increment the head by the number of byte - * that were written. User space function cs_etm_find_snapshot() will + * that were written. User space function __auxtrace_mmap__read() will * figure out how many bytes to get from the AUX buffer based on the * position of the head. */ diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index cd0fb7bfba68..a895931a2766 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -546,7 +546,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, /* * In snapshot mode we simply increment the head by the number of byte - * that were written. User space function cs_etm_find_snapshot() will + * that were written. User space function __auxtrace_mmap__read() will * figure out how many bytes to get from the AUX buffer based on the * position of the head. */ diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index d23c7690f29a..941abb70b827 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1573,7 +1573,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev, /* * In snapshot mode we simply increment the head by the number of byte - * that were written. User space function cs_etm_find_snapshot() will + * that were written. User space function __auxtrace_mmap__read() will * figure out how many bytes to get from the AUX buffer based on the * position of the head. */
Commit 2f01c200d440 ("perf cs-etm: Remove callback cs_etm_find_snapshot()") has removed the function cs_etm_find_snapshot() from the perf tool in the user space, now CoreSight trace directly uses the perf common function __auxtrace_mmap__read() to calcualte the head and size for AUX trace data in snapshot mode. Updates the comments in drivers to reflect the changes. Signed-off-by: Leo Yan <leo.yan@linaro.org> --- drivers/hwtracing/coresight/coresight-etb10.c | 2 +- drivers/hwtracing/coresight/coresight-tmc-etf.c | 2 +- drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-)