drm/i915: Use request retirement as context progress

As hangcheck score was removed, the active decay of score
was removed also. This removed feature for hangcheck to detect
if the gpu client was accidentally or maliciously causing intermittent
hangs. Reinstate the scoring as a per context property, so that if
one context starts to act unfavourably, ban it.

v2: ban_period_secs as a gate to score check (Chris)
v3: decay in proper spot. scores as tunables (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0ebec2b77ae1ea64a03d01d6acf69077c4a6831e..691f0b694e779eaa59a92fa0647d57e000638459 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -919,6 +919,11 @@ struct i915_ctx_hang_stats {
 
        /* This context is banned to submit more work */
        bool banned;
+
+#define CONTEXT_SCORE_GUILTY           10
+#define CONTEXT_SCORE_BAN_THRESHOLD    40
+       /* Accumulated score of hangs caused by this context */
+       int ban_score;
 };
 
 /* This must match up with the value previously used for execbuf2.rsvd1. */

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1f8dfd4aba61b38c9308937891468969bd8cd672..4c4aed2d2afb86faef721d1431d22fcd567fb393 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2622,33 +2622,45 @@ err_unlock:
 
 static bool i915_context_is_banned(const struct i915_gem_context *ctx)
 {
+       const struct i915_ctx_hang_stats *hs = &ctx->hang_stats;
        unsigned long elapsed;
 
-       if (ctx->hang_stats.banned)
+       if (hs->banned)
                return true;
 
-       elapsed = get_seconds() - ctx->hang_stats.guilty_ts;
-       if (ctx->hang_stats.ban_period_seconds &&
-           elapsed <= ctx->hang_stats.ban_period_seconds) {
+       if (!hs->ban_period_seconds)
+               return false;
+
+       elapsed = get_seconds() - hs->guilty_ts;
+       if (elapsed <= hs->ban_period_seconds) {
                DRM_DEBUG("context hanging too fast, banning!\n");
                return true;
        }
 
+       if (hs->ban_score >= CONTEXT_SCORE_BAN_THRESHOLD) {
+               DRM_DEBUG("context hanging too often, banning!\n");
+               return true;
+       }
+
        return false;
 }
 
-static void i915_set_reset_status(struct i915_gem_context *ctx,
-                                 const bool guilty)
+static void i915_gem_context_mark_guilty(struct i915_gem_context *ctx)
 {
        struct i915_ctx_hang_stats *hs = &ctx->hang_stats;
 
-       if (guilty) {
-               hs->banned = i915_context_is_banned(ctx);
-               hs->batch_active++;
-               hs->guilty_ts = get_seconds();
-       } else {
-               hs->batch_pending++;
-       }
+       hs->ban_score += CONTEXT_SCORE_GUILTY;
+
+       hs->banned = i915_context_is_banned(ctx);
+       hs->batch_active++;
+       hs->guilty_ts = get_seconds();
+}
+
+static void i915_gem_context_mark_innocent(struct i915_gem_context *ctx)
+{
+       struct i915_ctx_hang_stats *hs = &ctx->hang_stats;
+
+       hs->batch_pending++;
 }
 
 struct drm_i915_gem_request *
@@ -2713,7 +2725,11 @@ static void i915_gem_reset_engine(struct intel_engine_cs *engine)
                ring_hung = false;
        }
 
-       i915_set_reset_status(request->ctx, ring_hung);
+       if (ring_hung)
+               i915_gem_context_mark_guilty(request->ctx);
+       else
+               i915_gem_context_mark_innocent(request->ctx);
+
        if (!ring_hung)
                return;
 

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 27e8f257fb3996758300305808079bfc286efa51..60e63956ea1949368ccd193e869a576415caabc3 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -263,6 +263,10 @@ static void i915_gem_request_retire(struct drm_i915_gem_request *request)
                                               request->engine);
        }
 
+       /* Retirement decays the ban score as it is a sign of ctx progress */
+       if (request->ctx->hang_stats.ban_score > 0)
+               request->ctx->hang_stats.ban_score--;
+
        i915_gem_context_put(request->ctx);
 
        dma_fence_signal(&request->fence);