| Message ID | 1448902389-12477-3-git-send-email-mika.kuoppala@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Nov 30, 2015 at 06:53:08PM +0200, Mika Kuoppala wrote: > If we have accumulated hangcheck score before reaching > engine idle, that score will remain and is transferred to > the next set of batches. This is wrong as idle is a quite clear > boundary to prevent hangcheck score manipulation across batches. > > Fix this by clearing the score if engine reaches idle. The hangcheck accumulation is to detect denial of service by a sequence of batches that each take more than a hangcheck interval, being idle doesn't mean anything with respect to the slow dos. The only question is whether trying to do that at all is sensible. -Chris
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 3507269..c1d1400 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -3091,6 +3091,9 @@ static void i915_hangcheck_elapsed(struct work_struct *work) ring->hangcheck.acthd = ring->hangcheck.max_acthd = 0; } + if (!busy) + ring->hangcheck.score = 0; + ring->hangcheck.seqno = seqno; ring->hangcheck.acthd = acthd; busy_count += busy;
If we have accumulated hangcheck score before reaching engine idle, that score will remain and is transferred to the next set of batches. This is wrong as idle is a quite clear boundary to prevent hangcheck score manipulation across batches. Fix this by clearing the score if engine reaches idle. Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> --- drivers/gpu/drm/i915/i915_irq.c | 3 +++ 1 file changed, 3 insertions(+)