From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B248C433FE for ; Wed, 8 Sep 2021 21:10:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E21B960EE1 for ; Wed, 8 Sep 2021 21:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350729AbhIHVLz (ORCPT ); Wed, 8 Sep 2021 17:11:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349686AbhIHVLt (ORCPT ); Wed, 8 Sep 2021 17:11:49 -0400 Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EBEDC061757 for ; Wed, 8 Sep 2021 14:10:41 -0700 (PDT) Received: by mail-ot1-x334.google.com with SMTP id v33-20020a0568300921b0290517cd06302dso4729287ott.13 for ; Wed, 08 Sep 2021 14:10:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=OQuEnDMT6WUtAX5sNTKMuUkDGz5UCxdlBZTPt5Zal6o=; b=CEb9zvMBhkmBFfZvO9DRN5ZIcTkVd9jQynT0BR75wAil7bQ5zZ/hTxwnM5BphJnN05 f1e03hQK9XcdSmc/Uvy0Zw2I8uycMzxwjhvHzItTcjxoF1yqBr2Y9IM3gTqLUjGsVY2C Kgo879rFAikq1KgOxCod9OMEgJ4/lM36dkfJs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=OQuEnDMT6WUtAX5sNTKMuUkDGz5UCxdlBZTPt5Zal6o=; b=tElTm5xgjAGbKMreZu07BoOHmI1m8OszWGjUt4WSMsVQibR9Qvkf6TkzvJjXQMGUqJ d870NUvVvEPYlXmbi6F4OdNO4c3XGIXwLUIWpseWTNU8/OuOT5lV4IlDTa8ToG8//Yg7 sKcTqRH3lyAhIO2MHPxddGEvq7BXHFJXmdnmS5L6PUliTaIeStrjBrjtLvDRzE95cXOX FNTL09IOesFXchnMBZx08wt0NkgmeoPc1V+iqkvgohd/xu3Y9RQ8JlSylUhlyStziKt0 EpESFp2oW8NGSALJwujcE6bXU4cENGEuNX/Qy4oJjzl5pjO1I6CaU0YXyW7SHXDMNEJK 8EnQ== X-Gm-Message-State: AOAM5306xquWPt4oUq7d+pVPhXuFCVyF7Ydrma/Ny/gKFgK6cOlOlnqn /1WJY6eSzwhcsK57VMSDE+VZkAMbsGmHgbyAWULn5A== X-Google-Smtp-Source: ABdhPJzwHWUm3ViXy4KCDuCMhe8NVK5Q2Jx+/Jby7IB+QgX2f1DTCajON+qku3/di195nLVH6AFHNZFUoWCf/9oKPdQ= X-Received: by 2002:a9d:724a:: with SMTP id a10mr118901otk.323.1631135440479; Wed, 08 Sep 2021 14:10:40 -0700 (PDT) MIME-Version: 1.0 References: <20210903184806.1680887-1-robdclark@gmail.com> <20210903184806.1680887-9-robdclark@gmail.com> In-Reply-To: From: Daniel Vetter Date: Wed, 8 Sep 2021 23:10:29 +0200 Message-ID: Subject: Re: [PATCH v3 8/9] dma-buf/sync_file: Add SET_DEADLINE ioctl To: Rob Clark Cc: dri-devel , "moderated list:DMA BUFFER SHARING FRAMEWORK" , =?UTF-8?Q?Christian_K=C3=B6nig?= , =?UTF-8?Q?Michel_D=C3=A4nzer?= , Pekka Paalanen , Rob Clark , Sumit Semwal , Gustavo Padovan , =?UTF-8?Q?Christian_K=C3=B6nig?= , "open list:SYNC FILE FRAMEWORK" , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 8, 2021 at 9:36 PM Rob Clark wrote: > On Wed, Sep 8, 2021 at 11:49 AM Daniel Vetter wrote: > > On Wed, Sep 08, 2021 at 11:23:42AM -0700, Rob Clark wrote: > > > On Wed, Sep 8, 2021 at 10:50 AM Daniel Vetter wrote: > > > > > > > > On Fri, Sep 03, 2021 at 11:47:59AM -0700, Rob Clark wrote: > > > > > From: Rob Clark > > > > > > > > > > The initial purpose is for igt tests, but this would also be useful for > > > > > compositors that wait until close to vblank deadline to make decisions > > > > > about which frame to show. > > > > > > > > > > Signed-off-by: Rob Clark > > > > > > > > Needs userspace and I think ideally also some igts to make sure it works > > > > and doesn't go boom. > > > > > > See cover-letter.. there are igt tests, although currently that is the > > > only user. > > > > Ah sorry missed that. It would be good to record that in the commit too > > that adds the uapi. git blame doesn't find cover letters at all, unlike on > > gitlab where you get the MR request with everything. > > > > Ok there is the Link: thing, but since that only points at the last > > version all the interesting discussion is still usually lost, so I tend to > > not bother looking there. > > > > > I'd be ok to otherwise initially restrict this and the sw_sync UABI > > > (CAP_SYS_ADMIN? Or??) until there is a non-igt user, but they are > > > both needed by the igt tests > > > > Hm really awkward, uapi for igts in cross vendor stuff like this isn't > > great. I think hiding it in vgem is semi-ok (we have fences there > > already). But it's all a bit silly ... > > > > For the tests, should we instead have a selftest/Kunit thing to exercise > > this stuff? igt probably not quite the right thing. Or combine with a page > > flip if you want to test msm. > > Hmm, IIRC we have used CONFIG_BROKEN or something along those lines > for UABI in other places where we weren't willing to commit to yet? > > I suppose if we had to I could make this a sw_sync ioctl instead. But > OTOH there are kind of a limited # of ways this ioctl could look. And > we already know that at least some wayland compositors are going to > want this. Hm I was trying to think up a few ways this could work, but didn't come up with anything reasonable. Forcing the compositor to boost the entire chain (for gl composited primary plane fallback) is something the kernel can easily do too. Also only makes sense for priority boost, not so much for clock boosting, since clock boosting only really needs the final element to be boosted. > I guess I can look at non-igt options. But the igt test is already a > pretty convenient way to contrive situations (like loops, which is a > thing I need to add) Yeah it's definitely very useful for testing ... One option could be a hacky debugfs interface, where you write a fd number and deadline and the debugfs read function does the deadline setting. Horribly, but since it's debugfs no one ever cares. That's at least where we're hiding all the i915 hacks that igts need. -Daniel > BR, > -R > > > > -Daniel > > > > > > > > BR, > > > -R > > > > > > > -Daniel > > > > > > > > > --- > > > > > drivers/dma-buf/sync_file.c | 19 +++++++++++++++++++ > > > > > include/uapi/linux/sync_file.h | 20 ++++++++++++++++++++ > > > > > 2 files changed, 39 insertions(+) > > > > > > > > > > diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c > > > > > index 394e6e1e9686..f295772d5169 100644 > > > > > --- a/drivers/dma-buf/sync_file.c > > > > > +++ b/drivers/dma-buf/sync_file.c > > > > > @@ -459,6 +459,22 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, > > > > > return ret; > > > > > } > > > > > > > > > > +static int sync_file_ioctl_set_deadline(struct sync_file *sync_file, > > > > > + unsigned long arg) > > > > > +{ > > > > > + struct sync_set_deadline ts; > > > > > + > > > > > + if (copy_from_user(&ts, (void __user *)arg, sizeof(ts))) > > > > > + return -EFAULT; > > > > > + > > > > > + if (ts.pad) > > > > > + return -EINVAL; > > > > > + > > > > > + dma_fence_set_deadline(sync_file->fence, ktime_set(ts.tv_sec, ts.tv_nsec)); > > > > > + > > > > > + return 0; > > > > > +} > > > > > + > > > > > static long sync_file_ioctl(struct file *file, unsigned int cmd, > > > > > unsigned long arg) > > > > > { > > > > > @@ -471,6 +487,9 @@ static long sync_file_ioctl(struct file *file, unsigned int cmd, > > > > > case SYNC_IOC_FILE_INFO: > > > > > return sync_file_ioctl_fence_info(sync_file, arg); > > > > > > > > > > + case SYNC_IOC_SET_DEADLINE: > > > > > + return sync_file_ioctl_set_deadline(sync_file, arg); > > > > > + > > > > > default: > > > > > return -ENOTTY; > > > > > } > > > > > diff --git a/include/uapi/linux/sync_file.h b/include/uapi/linux/sync_file.h > > > > > index ee2dcfb3d660..f67d4ffe7566 100644 > > > > > --- a/include/uapi/linux/sync_file.h > > > > > +++ b/include/uapi/linux/sync_file.h > > > > > @@ -67,6 +67,18 @@ struct sync_file_info { > > > > > __u64 sync_fence_info; > > > > > }; > > > > > > > > > > +/** > > > > > + * struct sync_set_deadline - set a deadline on a fence > > > > > + * @tv_sec: seconds elapsed since epoch > > > > > + * @tv_nsec: nanoseconds elapsed since the time given by the tv_sec > > > > > + * @pad: must be zero > > > > > + */ > > > > > +struct sync_set_deadline { > > > > > + __s64 tv_sec; > > > > > + __s32 tv_nsec; > > > > > + __u32 pad; > > > > > +}; > > > > > + > > > > > #define SYNC_IOC_MAGIC '>' > > > > > > > > > > /** > > > > > @@ -95,4 +107,12 @@ struct sync_file_info { > > > > > */ > > > > > #define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info) > > > > > > > > > > + > > > > > +/** > > > > > + * DOC: SYNC_IOC_SET_DEADLINE - set a deadline on a fence > > > > > + * > > > > > + * Allows userspace to set a deadline on a fence, see dma_fence_set_deadline() > > > > > + */ > > > > > +#define SYNC_IOC_SET_DEADLINE _IOW(SYNC_IOC_MAGIC, 5, struct sync_set_deadline) > > > > > + > > > > > #endif /* _UAPI_LINUX_SYNC_H */ > > > > > -- > > > > > 2.31.1 > > > > > > > > > > > > > -- > > > > Daniel Vetter > > > > Software Engineer, Intel Corporation > > > > http://blog.ffwll.ch > > > > -- > > Daniel Vetter > > Software Engineer, Intel Corporation > > http://blog.ffwll.ch -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch