[Intel-wired-lan] [PATCH net-next v3] ice: add tracepoints

[Brelinski, TonyX <tonyx.brelinski@intel.com>]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Jesse Brandeburg
> Sent: Tuesday, June 8, 2021 4:35 PM
> To: intel-wired-lan at lists.osuosl.org
> Cc: Shelton, Benjamin H <benjamin.h.shelton@intel.com>
> Subject: [Intel-wired-lan] [PATCH net-next v3] ice: add tracepoints
> 
> This patch is modeled after one by Scott Peterson for i40e.
> 
> Add tracepoints to the driver, via a new file ice_trace.h and some new trace
> calls added in interesting places in the driver. Add some tracing for DIMLIB to
> help debug interrupt moderation problems.
> 
> Performance should not be affected, and this can be very useful for
> debugging and adding new trace events to paths in the future.
> 
> Note eBPF programs can attach to these events, as well as perf can count
> them since we're attaching to the events subsystem in the kernel.
> 
> Co-developed-by: Ben Shelton <benjamin.h.shelton@intel.com>
> Signed-off-by: Ben Shelton <benjamin.h.shelton@intel.com>
> Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
> ---
> NOTE: checkpatch will complain about this patch due to the macros defining
> the new trace functionality being formatted for readability.
> 
> Testing Hints:
> See that performance is unaffected while tracepoints are present but
> disabled (default state). Enable them all and see they appear in
> /sys/kernel/debug/tracing/trace when exercised, and after 'make install'
> you can see the events in perf list.
> 
> When disabled, a tracepoint reduces to a 5-byte no-op. When enabled, that
> code is patched to jump to the tracepoint clause, which is located
> somewhere nearby.  See include/linux/jump_label.h for info in static keys,
> and samples/trace-events/trace-events-samples.[ch] for info on the trace
> events.
> 
> To test tracepoints:
> insmod ice and bring up a link
> cd /sys/kernel/debug/tracing
> echo > trace
> echo 1 > events/ice/enable
> send something over ice
> cat trace
> echo 0 > events/ice/enable
> 
> ---
> v3: fixed transposed rx/tx reference in receive code
> v2: updated commit message and copyright on new file
> ---
>  drivers/net/ethernet/intel/ice/ice_main.c  |   8 +
>  drivers/net/ethernet/intel/ice/ice_trace.h | 232 +++++++++++++++++++++
>  drivers/net/ethernet/intel/ice/ice_txrx.c  |   9 +
>  3 files changed, 249 insertions(+)
>  create mode 100644 drivers/net/ethernet/intel/ice/ice_trace.h

Tested-by: Tony Brelinski <tonyx.brelinski@intel.com> (A Contingent Worker at Intel)