From 4900727d35bb20028f9bd83146ec4bf78afffe30 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 11 Jan 2018 07:30:31 +0000 Subject: [PATCH] drm/i915/pmu: Reconstruct active state on starting busy-stats We have a hole in our busy-stat accounting if the pmu is enabled during a long running batch, the pmu will not start accumulating busy-time until the next context switch. This then fails tests that are only sampling a single batch. v2: Count each active port just once (context in/out events are only on the first and last assignment to a port). v3: Avoid hardcoding knowledge of 2 submission ports Fixes: 30e17b7847f5 ("drm/i915: Engine busy time tracking") Testcase: igt/perf_pmu/busy-start Testcase: igt/perf_pmu/busy-double-start Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20180111073031.14614-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_engine_cs.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 6bb51a502b8b..d790bdc227ff 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -1951,8 +1951,22 @@ int intel_enable_engine_stats(struct intel_engine_cs *engine) spin_lock_irqsave(&engine->stats.lock, flags); if (engine->stats.enabled == ~0) goto busy; - if (engine->stats.enabled++ == 0) + if (engine->stats.enabled++ == 0) { + struct intel_engine_execlists *execlists = &engine->execlists; + const struct execlist_port *port = execlists->port; + unsigned int num_ports = execlists_num_ports(execlists); + engine->stats.enabled_at = ktime_get(); + + /* XXX submission method oblivious? */ + while (num_ports-- && port_isset(port)) { + engine->stats.active++; + port++; + } + + if (engine->stats.active) + engine->stats.start = engine->stats.enabled_at; + } spin_unlock_irqrestore(&engine->stats.lock, flags); return 0; -- 2.30.2