From 74f9474124ea53f98866e434a8080f1538b8c2b7 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 3 May 2018 20:54:16 +0100 Subject: [PATCH] drm/i915/execlists: Drop preemption arbitrations points along the ring MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Cc: Michał Winiarski Cc: Michel Thierry Cc: Joonas Lahtinen Reviewed-by: Tvrtko Ursulin Reviewed-by: Michel Thierry Reviewed-by: Lionel Landwerlin Link: https://patchwork.freedesktop.org/patch/msgid/20180503195416.22498-1-chris@chris-wilson.co.uk --- 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); -- 2.30.2