From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andres Rodriguez Subject: Re: [PATCH] dma-buf: avoid scheduling on fence status query Date: Wed, 26 Apr 2017 10:28:49 -0400 Message-ID: <5c38fa6a-7be1-d2d3-13fd-ec3d527cf021@gmail.com> References: <20170426013632.4716-1-andresx7@gmail.com> <6a3b44f0-bc9f-462c-9b0f-96ae15712b8b@vodafone.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Sender: linux-media-owner@vger.kernel.org To: =?UTF-8?Q?Christian_K=c3=b6nig?= , Dave Airlie Cc: dri-devel , "linaro-mm-sig@lists.linaro.org" , Linux Media Mailing List List-Id: dri-devel@lists.freedesktop.org On 2017-04-26 06:13 AM, Christian König wrote: > Am 26.04.2017 um 11:59 schrieb Dave Airlie: >> On 26 April 2017 at 17:20, Christian König >> wrote: >>> NAK, I'm wondering how often I have to reject that change. We should >>> probably add a comment here. >>> >>> Even with a zero timeout we still need to enable signaling, otherwise >>> some >>> fence will never signal if userspace just polls on them. >>> >>> If a caller is only interested in the fence status without enabling the >>> signaling it should call dma_fence_is_signaled() instead. >> Can we not move the return 0 (with spin unlock) down after we enabling >> signalling, but before >> we enter the schedule_timeout(1)? > > Yes, that would be an option. > I was actually arguing with Dave about this on IRC yesterday. Seems like I owe him a beer now. -Andres > Christian. > >> >> Dave. > >