<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Exchange Server"> <style></style> </head> <body> <div>Yes, to be comptibility, I kept both seq_no and syncfile fd in the patch set, you can take a look, which really is simpler and effective way. syncfile indeed be a good way to pass fence for user space, which already is proved in Android and is upstreamed. Regards, David Zhou 发自坚果 Pro <style type="text/css">  </style> <div class="x_quote"> <div style="margin:0 0px; font-size:105%">Marek Ol?醟 <maraeo@gmail.com> 于 2017年9月13日下午8:06写道：</div> </div> </div> <div class="PlainText">On Wed, Sep 13, 2017 at 1:32 PM, Zhou, David(ChunMing) <David1.Zhou@amd.com> wrote: > Could you describe how difficult to directly use CS syncfile fd in Mesa > compared with concerting CS seq to syncfile fd via several syncobj ioctls? It just simplifies things. Mesa primarily uses seq_no-based fences and will continue to use them. We can't remove the seq_no fence code because we have to keep Mesa compatible with older kernels. The only possibilities are: - Mesa gets both seq_no and sync_file from CS. - Mesa only gets seq_no from CS. I decided to take the simpler option. I don't know if there is a perf difference between CS returning a sync_file and using a separate ioctl, but it's probably insignificant since we already call 3 ioctls per IB submission (BO list create+destroy, submit). Marek > > Regards, > David Zhou > > 发自坚果 Pro > > Marek Ol?醟 <maraeo@gmail.com> 于 2017年9月13日下午6:11写道： > > On Wed, Sep 13, 2017 at 5:03 AM, zhoucm1 <david1.zhou@amd.com> wrote: >> Hi Marek, >> >> You're doing same things with me, see my "introduce syncfile as fence >> reuturn" patch set, which makes things more simple, we just need to >> directly >> return syncfile fd to UMD when CS, then the fence UMD get will be always >> syncfile fd, UMD don't need to construct ip_type/ip_instance/ctx_id/ring >> any >> more, which also can pass to dependency and syncobj as well. > > For simpler Mesa code, Mesa won't get a sync file from the CS ioctl. > > Marek </div> </body> </html>