From 61642ff03523995918c452ef41adf0795d54d909 Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Tue, 1 Dec 2015 17:56:12 +0200 Subject: [PATCH] drm/i915: Inspect subunit states on hangcheck If head seems stuck and engine in question is rcs, inspect subunit state transitions from undone to done, before deciding that this really is a hang instead of limited progress. Only account the transitions of subunits from undone to done once, to prevent unstable subunit states to keep us falsely active. As this adds one extra steps to hangcheck heuristics, before hang is declared, it adds 1500ms to to detect hang for render ring to a total of 7500ms. We could sample the subunit states on first head stuck condition but decide not to do so only in order to mimic old behaviour. This way the check order of promotion from seqno > atchd > instdone is consistently done. v2: Deal with unstable done states (Arun) Clear instdone progress on head and seqno movement (Chris) Report raw and accumulated instdone's in in debugfs (Chris) Return HANGCHECK_ACTIVE on undone->done References: https://bugs.freedesktop.org/show_bug.cgi?id=93029 Cc: Chris Wilson Cc: Dave Gordon Cc: Daniel Vetter Cc: Arun Siluvery Reviewed-by: Chris Wilson Signed-off-by: Mika Kuoppala Link: http://patchwork.freedesktop.org/patch/msgid/1448985372-19535-1-git-send-email-mika.kuoppala@intel.com --- drivers/gpu/drm/i915/i915_debugfs.c | 20 +++++++- drivers/gpu/drm/i915/i915_irq.c | 62 +++++++++++++++++++++++-- drivers/gpu/drm/i915/intel_ringbuffer.h | 1 + 3 files changed, 77 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 3b05bd189eab..e3377abc0d4d 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -1331,7 +1331,8 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused) struct intel_engine_cs *ring; u64 acthd[I915_NUM_RINGS]; u32 seqno[I915_NUM_RINGS]; - int i; + u32 instdone[I915_NUM_INSTDONE_REG]; + int i, j; if (!i915.enable_hangcheck) { seq_printf(m, "Hangcheck disabled\n"); @@ -1345,6 +1346,8 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused) acthd[i] = intel_ring_get_active_head(ring); } + i915_get_extra_instdone(dev, instdone); + intel_runtime_pm_put(dev_priv); if (delayed_work_pending(&dev_priv->gpu_error.hangcheck_work)) { @@ -1365,6 +1368,21 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused) (long long)ring->hangcheck.max_acthd); seq_printf(m, "\tscore = %d\n", ring->hangcheck.score); seq_printf(m, "\taction = %d\n", ring->hangcheck.action); + + if (ring->id == RCS) { + seq_puts(m, "\tinstdone read ="); + + for (j = 0; j < I915_NUM_INSTDONE_REG; j++) + seq_printf(m, " 0x%08x", instdone[j]); + + seq_puts(m, "\n\tinstdone accu ="); + + for (j = 0; j < I915_NUM_INSTDONE_REG; j++) + seq_printf(m, " 0x%08x", + ring->hangcheck.instdone[j]); + + seq_puts(m, "\n"); + } } return 0; diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index fa8afa7860ae..b775decf9d27 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2949,14 +2949,44 @@ static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv) ring->hangcheck.deadlock = 0; } -static enum intel_ring_hangcheck_action -ring_stuck(struct intel_engine_cs *ring, u64 acthd) +static bool subunits_stuck(struct intel_engine_cs *ring) { - struct drm_device *dev = ring->dev; - struct drm_i915_private *dev_priv = dev->dev_private; - u32 tmp; + u32 instdone[I915_NUM_INSTDONE_REG]; + bool stuck; + int i; + + if (ring->id != RCS) + return true; + + i915_get_extra_instdone(ring->dev, instdone); + /* There might be unstable subunit states even when + * actual head is not moving. Filter out the unstable ones by + * accumulating the undone -> done transitions and only + * consider those as progress. + */ + stuck = true; + for (i = 0; i < I915_NUM_INSTDONE_REG; i++) { + const u32 tmp = instdone[i] | ring->hangcheck.instdone[i]; + + if (tmp != ring->hangcheck.instdone[i]) + stuck = false; + + ring->hangcheck.instdone[i] |= tmp; + } + + return stuck; +} + +static enum intel_ring_hangcheck_action +head_stuck(struct intel_engine_cs *ring, u64 acthd) +{ if (acthd != ring->hangcheck.acthd) { + + /* Clear subunit states on head movement */ + memset(ring->hangcheck.instdone, 0, + sizeof(ring->hangcheck.instdone)); + if (acthd > ring->hangcheck.max_acthd) { ring->hangcheck.max_acthd = acthd; return HANGCHECK_ACTIVE; @@ -2965,6 +2995,24 @@ ring_stuck(struct intel_engine_cs *ring, u64 acthd) return HANGCHECK_ACTIVE_LOOP; } + if (!subunits_stuck(ring)) + return HANGCHECK_ACTIVE; + + return HANGCHECK_HUNG; +} + +static enum intel_ring_hangcheck_action +ring_stuck(struct intel_engine_cs *ring, u64 acthd) +{ + struct drm_device *dev = ring->dev; + struct drm_i915_private *dev_priv = dev->dev_private; + enum intel_ring_hangcheck_action ha; + u32 tmp; + + ha = head_stuck(ring, acthd); + if (ha != HANGCHECK_HUNG) + return ha; + if (IS_GEN2(dev)) return HANGCHECK_HUNG; @@ -3106,7 +3154,11 @@ static void i915_hangcheck_elapsed(struct work_struct *work) if (ring->hangcheck.score > 0) ring->hangcheck.score--; + /* Clear head and subunit states on seqno movement */ ring->hangcheck.acthd = ring->hangcheck.max_acthd = 0; + + memset(ring->hangcheck.instdone, 0, + sizeof(ring->hangcheck.instdone)); } ring->hangcheck.seqno = seqno; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 49574ffe54bc..7349d9258191 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -93,6 +93,7 @@ struct intel_ring_hangcheck { int score; enum intel_ring_hangcheck_action action; int deadlock; + u32 instdone[I915_NUM_INSTDONE_REG]; }; struct intel_ringbuffer { -- 2.20.1