From 4ef10fe05ba0b08ce7029c07878afe3c8d5754d8 Mon Sep 17 00:00:00 2001 From: Lionel Landwerlin Date: Tue, 24 Mar 2020 11:54:57 -0700 Subject: drm/i915/perf: add new open param to configure polling of OA buffer This new parameter let's the application choose how often the OA buffer should be checked on the CPU side for data availability. Longer polling period tend to reduce CPU overhead if the application does not care about somewhat real time data collection. v2: Allow disabling polling completely with 0 value (Lionel) v3: Version the new parameter (Joonas) v4: Rebase (Umesh) v5: Make poll delay value of 0 invalid (Umesh) v6: - Describe poll_oa_period (Ashutosh) - Fix comment for new poll parameter (Lionel) - Drop open_flags in read_properties_unlocked (Lionel) - Rename uapi parameter (Ashutosh) v7: Reword the comment in uapi (Ashutosh) Signed-off-by: Lionel Landwerlin Signed-off-by: Umesh Nerlige Ramappa Reviewed-by: Ashutosh Dixit Signed-off-by: Lionel Landwerlin Link: https://patchwork.freedesktop.org/patch/msgid/20200324185457.14635-4-umesh.nerlige.ramappa@intel.com --- include/uapi/drm/i915_drm.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include') diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index db649d03ab52..14b67cd6b54b 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -1980,6 +1980,19 @@ enum drm_i915_perf_property_id { */ DRM_I915_PERF_PROP_GLOBAL_SSEU, + /** + * This optional parameter specifies the timer interval in nanoseconds + * at which the i915 driver will check the OA buffer for available data. + * Minimum allowed value is 100 microseconds. A default value is used by + * the driver if this parameter is not specified. Note that larger timer + * values will reduce cpu consumption during OA perf captures. However, + * excessively large values would potentially result in OA buffer + * overwrites as captures reach end of the OA buffer. + * + * This property is available in perf revision 5. + */ + DRM_I915_PERF_PROP_POLL_OA_PERIOD, + DRM_I915_PERF_PROP_MAX /* non-ABI */ }; -- cgit v1.2.3