From: Ilia Mirkin Date: Sat, 10 Oct 2015 05:56:09 +0000 (-0400) Subject: nouveau: avoid emitting new fences unnecessarily X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8053c9208f30964d89dc4e262fdf2148f0664696;p=mesa.git nouveau: avoid emitting new fences unnecessarily Right now we emit on every kick, but this is only necessary if something will ever be able to observe that the fence completed. If there are no refs, leave the fence alone and emit it another day. This also happens to work around an issue for the kick handler -- a kick can be a result of e.g. nouveau_bo_wait or explicit kick, or it can be due to lack of space in the pushbuf. We want the emit to happen in the current batch, so we want there to always be enough space. However an explicit kick could take the reserved space for the implicitly-triggered kick's fence emission if it happened right after. With the new mechanism, hopefully there's no way to cause two fences to be emitted into the same reserved space. Signed-off-by: Ilia Mirkin Reviewed-by: Samuel Pitoiset Fixes: 47d11990b (nouveau: make sure there's always room to emit a fence) Cc: mesa-stable@lists.freedesktop.org --- diff --git a/src/gallium/drivers/nouveau/nouveau_fence.c b/src/gallium/drivers/nouveau/nouveau_fence.c index ee4e08dd520..18b15920185 100644 --- a/src/gallium/drivers/nouveau/nouveau_fence.c +++ b/src/gallium/drivers/nouveau/nouveau_fence.c @@ -190,8 +190,10 @@ nouveau_fence_wait(struct nouveau_fence *fence) /* wtf, someone is waiting on a fence in flush_notify handler? */ assert(fence->state != NOUVEAU_FENCE_STATE_EMITTING); - if (fence->state < NOUVEAU_FENCE_STATE_EMITTED) + if (fence->state < NOUVEAU_FENCE_STATE_EMITTED) { + PUSH_SPACE(screen->pushbuf, 8); nouveau_fence_emit(fence); + } if (fence->state < NOUVEAU_FENCE_STATE_FLUSHED) if (nouveau_pushbuf_kick(screen->pushbuf, screen->pushbuf->channel)) @@ -224,8 +226,12 @@ nouveau_fence_wait(struct nouveau_fence *fence) void nouveau_fence_next(struct nouveau_screen *screen) { - if (screen->fence.current->state < NOUVEAU_FENCE_STATE_EMITTING) - nouveau_fence_emit(screen->fence.current); + if (screen->fence.current->state < NOUVEAU_FENCE_STATE_EMITTING) { + if (screen->fence.current->ref > 1) + nouveau_fence_emit(screen->fence.current); + else + return; + } nouveau_fence_ref(NULL, &screen->fence.current);