On Thu, Apr 06, 2017 at 02:49:54PM +0000, Dong, Chuanxiao wrote: > > > > -----Original Message----- > > From: Chris Wilson [mailto:ch...@chris-wilson.co.uk] > > Sent: Thursday, April 6, 2017 10:19 PM > > To: Dong, Chuanxiao > > Cc: intel-gfx@lists.freedesktop.org; intel-gvt-...@lists.freedesktop.org; > > Zheng, Xiao; Tian, Kevin; joonas.lahti...@linux.intel.com > > Subject: Re: [PATCH v2 2/2] drm/i915/scheduler: add gvt notification for guc > > > > On Thu, Apr 06, 2017 at 02:05:15PM +0000, Dong, Chuanxiao wrote: > > > > > > > > > > -----Original Message----- > > > > From: Chris Wilson [mailto:ch...@chris-wilson.co.uk] > > > > Sent: Thursday, April 6, 2017 9:32 PM > > > > To: Dong, Chuanxiao > > > > Cc: intel-gfx@lists.freedesktop.org; > > > > intel-gvt-...@lists.freedesktop.org; > > > > Zheng, Xiao; Tian, Kevin; joonas.lahti...@linux.intel.com > > > > Subject: Re: [PATCH v2 2/2] drm/i915/scheduler: add gvt notification > > > > for guc > > > > > > > > On Tue, Mar 28, 2017 at 05:38:41PM +0800, Chuanxiao Dong wrote: > > > > > GVT request needs a manual mmio load/restore. Before GuC submit a > > > > > request, send notification to gvt for mmio loading. And after the > > > > > GuC finished this GVT request, notify gvt again for mmio restore. > > > > > This follows the usage when using execlists submission. > > > > > > > > > > Cc: xiao.zh...@intel.com > > > > > Cc: kevin.t...@intel.com > > > > > Cc: joonas.lahti...@linux.intel.com > > > > > Cc: ch...@chris-wilson.co.uk > > > > > Signed-off-by: Chuanxiao Dong <chuanxiao.d...@intel.com> > > > > > --- > > > > > drivers/gpu/drm/i915/i915_guc_submission.c | 4 ++++ > > > > > drivers/gpu/drm/i915/intel_gvt.h | 12 ++++++++++++ > > > > > drivers/gpu/drm/i915/intel_lrc.c | 21 +++------------------ > > > > > 3 files changed, 19 insertions(+), 18 deletions(-) > > > > > > > > > > diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > b/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > index 58087630..d8a5942 100644 > > > > > --- a/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > +++ b/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > @@ -606,6 +606,8 @@ static void __i915_guc_submit(struct > > > > drm_i915_gem_request *rq) > > > > > unsigned long flags; > > > > > int b_ret; > > > > > > > > > > + intel_gvt_notify_context_status(rq, INTEL_CONTEXT_SCHEDULE_IN); > > > > > + > > > > > /* WA to flush out the pending GMADR writes to ring buffer. */ > > > > > if (i915_vma_is_map_and_fenceable(rq->ring->vma)) > > > > > POSTING_READ_FW(GUC_STATUS); > > > > > @@ -725,6 +727,8 @@ static void i915_guc_irq_handler(unsigned long > > data) > > > > > rq = port[0].request; > > > > > while (rq && i915_gem_request_completed(rq)) { > > > > > trace_i915_gem_request_out(rq); > > > > > + intel_gvt_notify_context_status(rq, > > > > > + INTEL_CONTEXT_SCHEDULE_OUT); > > > > > > > > This is incorrect though. This is no better than just waiting for > > > > the request, which is not enough since the idea is that you need to > > > > wait for the context image to be completely written to memory before > > you read it. > > > > -Chris > > > > > > The wait for the context image to be completely written will be done in > > > the > > notification from the GVT, by checking the CSB. If put the wait here will > > made > > each i915 request to wait, which seems not necessary. > > > > Urm, no. I hope you mean the wait will be on some other thread than inside > > this interrupt handler. > > The SCHEDULE_OUT means to stop GuC to submit another request before the > current one is completed by GVT so GVT can manually restore the MMIO. So this > irq handler should wait until SCHEDULE_OUT is completed. How it possible to > make this irq handler to wait for another thread? From the current software > architecture there is no other thread....
No. It is not acceptable to have any blocking here. Rather you delegate the polling of CSB to a thread/worker that you kick off from this notify. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
