Limit the arbitration (where preemption may occur) to inside the batch, and prevent it from happening on the pipecontrols/flushes we use to write the breadcrumb seqno. Once the user batch is complete, we have nothing left to do but serialise and emit the breadcrumb; switching contexts at this point is futile so don't. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Michał Winiarski <michal.winiarski@xxxxxxxxx> Cc: Michel Thierry <michel.thierry@xxxxxxxxx> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> --- Michał and Michel, please take a look and see if you can think of any objections. -Chris --- drivers/gpu/drm/i915/intel_lrc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 3d747d1c3d4d..9f3cce022b2d 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1933,7 +1933,7 @@ static int gen8_emit_bb_start(struct i915_request *rq, rq->ctx->ppgtt->pd_dirty_rings &= ~intel_engine_flag(rq->engine); } - cs = intel_ring_begin(rq, 4); + cs = intel_ring_begin(rq, 6); if (IS_ERR(cs)) return PTR_ERR(cs); @@ -1962,6 +1962,9 @@ static int gen8_emit_bb_start(struct i915_request *rq, (flags & I915_DISPATCH_RS ? MI_BATCH_RESOURCE_STREAMER : 0); *cs++ = lower_32_bits(offset); *cs++ = upper_32_bits(offset); + + *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE; + *cs++ = MI_NOOP; intel_ring_advance(rq, cs); return 0; @@ -2104,7 +2107,7 @@ static void gen8_emit_breadcrumb(struct i915_request *request, u32 *cs) cs = gen8_emit_ggtt_write(cs, request->global_seqno, intel_hws_seqno_address(request->engine)); *cs++ = MI_USER_INTERRUPT; - *cs++ = MI_NOOP; + *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; request->tail = intel_ring_offset(request, cs); assert_ring_tail_valid(request->ring, request->tail); @@ -2120,7 +2123,7 @@ static void gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs) cs = gen8_emit_ggtt_write_rcs(cs, request->global_seqno, intel_hws_seqno_address(request->engine)); *cs++ = MI_USER_INTERRUPT; - *cs++ = MI_NOOP; + *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; request->tail = intel_ring_offset(request, cs); assert_ring_tail_valid(request->ring, request->tail); -- 2.17.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
