• Chris Wilson's avatar
    drm/i915: Identify active requests · 85474441
    Chris Wilson authored
    To allow requests to forgo a common execution timeline, one question we
    need to be able to answer is "is this request running?". To track
    whether a request has started on HW, we can emit a breadcrumb at the
    beginning of the request and check its timeline's HWSP to see if the
    breadcrumb has advanced past the start of this request. (This is in
    contrast to the global timeline where we need only ask if we are on the
    global timeline and if the timeline has advanced past the end of the
    previous request.)
    
    There is still confusion from a preempted request, which has already
    started but relinquished the HW to a high priority request. For the
    common case, this discrepancy should be negligible. However, for
    identification of hung requests, knowing which one was running at the
    time of the hang will be much more important.
    Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
    Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20190129185452.20989-2-chris@chris-wilson.co.uk
    85474441
intel_lrc.c 83 KB