<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, Jul 5, 2017 at 11:42 AM, Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk" target="_blank">chris@chris-wilson.co.uk</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Quoting Jason Ekstrand (2017-07-05 19:32:21) <div><div class="h5">> On Wed, Jul 5, 2017 at 10:37 AM, Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>> wrote: > > Quoting Jason Ekstrand (2017-07-05 18:21:22) > > This commit adds support for waiting on or signaling DRM syncobjs as > > part of execbuf. It does so by hijacking the currently unused cliprects > > pointer to instead point to an array of i915_gem_exec_fence structs > > which containe a DRM syncobj and a flags parameter which specifies > > whether to wait on it or to signal it. This implementation > > theoretically allows for both flags to be set in which case it waits on > > the dma_fence that was in the syncobj and then immediately replaces it > > with the dma_fence from the current execbuf. > > > > Cc: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>> > > --- > > > > Ideally, I'd like to get whatever kernel reviewing and/or merging is > > required to land the userspace bits ASAP. That said, I understand that > > this is my first kernel patch and it's liable to have a few rounds of > > review before going in. :-) > > > > The mesa branch for using this in Vulkan can be found here: > > > > <a href="https://cgit.freedesktop.org/~jekstrand/mesa/log/?h=review/anv-syncobj" rel="noreferrer" target="_blank">https://cgit.freedesktop.org/~jekstrand/mesa/log/?h=review/anv-syncobj</a> > > > > drivers/gpu/drm/i915/i915_drv.c | 3 +- > > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 97 > ++++++++++++++++++++++++++++-- > > include/uapi/drm/i915_drm.h | 30 ++++++++- > > 3 files changed, 121 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_ > drv.c > > index 9167a73..e6f7f49 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.c > > +++ b/drivers/gpu/drm/i915/i915_drv.c > > @@ -384,6 +384,7 @@ static int i915_getparam(struct drm_device *dev, void > *data, > > case I915_PARAM_HAS_EXEC_FENCE: > > case I915_PARAM_HAS_EXEC_CAPTURE: > > case I915_PARAM_HAS_EXEC_BATCH_FIRST: > > + case I915_PARAM_HAS_EXEC_FENCE_ARRAY: > > /* For the time being all of these are always true; > > * if some supported hardware does not have one of these > > * features this value needs to be provided from > > @@ -2734,7 +2735,7 @@ static struct drm_driver driver = { > > */ > > .driver_features = > > DRIVER_HAVE_IRQ | DRIVER_IRQ_SHARED | DRIVER_GEM | > DRIVER_PRIME | > > - DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC, > > + DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | > DRIVER_SYNCOBJ, > > .release = i915_driver_release, > > .open = i915_driver_open, > > .lastclose = i915_driver_lastclose, > > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm > /i915/i915_gem_execbuffer.c > > index 929f275..81b7b7b 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > @@ -33,6 +33,7 @@ > > > > #include <drm/drmP.h> > > #include <drm/i915_drm.h> > > +#include <drm/drm_syncobj.h> > > > > #include "i915_drv.h" > > #include "i915_gem_clflush.h" > > @@ -1882,8 +1883,10 @@ static bool i915_gem_check_execbuffer(struct > drm_i915_gem_execbuffer2 *exec) > > return false; > > > > /* Kernel clipping was a DRI1 misfeature */ > > - if (exec->num_cliprects || exec->cliprects_ptr) > > - return false; > > + if (!(exec->flags & I915_EXEC_FENCE_ARRAY)) { > > + if (exec->num_cliprects || exec->cliprects_ptr) > > + return false; > > + } > > > > if (exec->DR4 == 0xffffffff) { > > DRM_DEBUG("UXA submitting garbage DR4, fixing up\n"); > > @@ -2118,12 +2121,15 @@ static int > > i915_gem_do_execbuffer(struct drm_device *dev, > > struct drm_file *file, > > struct drm_i915_gem_execbuffer2 *args, > > - struct drm_i915_gem_exec_object2 *exec) > > + struct drm_i915_gem_exec_object2 *exec, > > + struct drm_i915_gem_exec_fence *fences) > > { > > struct i915_execbuffer eb; > > struct dma_fence *in_fence = NULL; > > struct sync_file *out_fence = NULL; > > + struct drm_syncobj **syncobjs = NULL; > > int out_fence_fd = -1; > > + unsigned int i; > > int err; > > > > BUILD_BUG_ON(__EXEC_OBJECT_INTERNAL_FLAGS & > > @@ -2186,9 +2192,30 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > } > > } > > > > + if (args->flags & I915_EXEC_FENCE_ARRAY) { > > + syncobjs = kvmalloc_array(args->num_cliprects, > > + sizeof(*syncobjs), > > + __GFP_NOWARN | GFP_TEMPORARY | > > + __GFP_ZERO); > > + if (syncobjs == NULL) { > > + DRM_DEBUG("Failed to allocate array of %d > syncobjs\n", > > + args->num_cliprects); > > + err = -ENOMEM; > > + goto err_out_fence; > > + } > > + for (i = 0; i < args->num_cliprects; i++) { > > + syncobjs[i] = drm_syncobj_find(file, fences > [i].handle); > > + if (!syncobjs[i]) { > > + DRM_DEBUG("Invalid syncobj handle > provided\n"); > > + err = -EINVAL; > > + goto err_syncobjs; > > + } > > + } > > I did this in the caller so that we only allocated and passed in a single > array of drm_syncobj (with the flags packed into the low bits). > > > Packing things into the low bits seems a bit sketchy but it works so long as we > only have the two flag bits. > > > > + } > > + > > err = eb_create(&eb); > > if (err) > > - goto err_out_fence; > > + goto err_syncobjs; > > > > GEM_BUG_ON(!eb.lut_size); > > > > @@ -2304,6 +2331,16 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > goto err_request; > > } > > > > + if (args->flags & I915_EXEC_FENCE_ARRAY) { > > + for (i = 0; i < args->num_cliprects; i++) { > > + if (fences[i].flags & I915_EXEC_FENCE_WAIT) { > > + if (i915_gem_request_await_dma_fence > (eb.request, > > + > syncobjs[i]->fence)) > > + goto err_request; > > + } > > + } > > + } > > + > > if (out_fence_fd != -1) { > > out_fence = sync_file_create(&eb.request->fence); > > if (!out_fence) { > > @@ -2312,6 +2349,20 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > } > > } > > > > + /* We need to add fences to syncobjs last because doing so mutates > the > > + * syncobj and we have no good way to recover if the execbuf fails > > + * after this point. Fortunately, drm_syncobj_replace_fence can > never > > + * fail. > > + */ > > + if (args->flags & I915_EXEC_FENCE_ARRAY) { > > + for (i = 0; i < args->num_cliprects; i++) { > > + if (fences[i].flags & I915_EXEC_FENCE_SIGNAL) { > > + drm_syncobj_replace_fence(file, syncobjs > [i], > > + &eb.request-> > fence); > > + } > > + } > > + } > > + > > This has to be after the execbuf is submitted, next to where out_fence > is attached is a good spot, and should only be updated on success. (The > kernel API allows combining of FENCE_WAIT | FENCE_SIGNAL so we can only > replace a FENCE_WAIT once we know we have committed the execbuf.) > > > It's currently right after we call > > out_fence = sync_file_create(&eb.request->fence); </div></div>That's where we create the out fence, not where we attach it to the request, see the fd_install, which is after we have successfully committed the request. > which is before eb_submit(). Are sync files wrong? Note that I was careful to > ensure that there are no error paths after syncobj_replace_fence so we know for > 100% sure that it will be committed, hence the comment. There's the rather big one in eb_submit() that will generate EINTR for your pain. </blockquote><div> </div><div>Oh. :( I see it now. I'll move to right around fd_install() </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> > I moved all of these to little functions: get_fence_array, > await_fence_array, signal_fence_array and put_fence_array. > > > You clearly have a version of this patch somewhere. Where can I find it? It's still on the older syncobj api, I am easily distracted. :| </blockquote><div> </div><div>That's ok. If you could just point me at it, I'm happy to either pull the good ideas into mine or rebase it, whichever is easier. </div></div></div></div>