Messages in this thread | | | Subject | Re: [RFC] /dev/ioasid uAPI proposal | From | Jason Wang <> | Date | Tue, 8 Jun 2021 09:10:42 +0800 |
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在 2021/6/3 上午1:21, Jason Gunthorpe 写道: > On Wed, Jun 02, 2021 at 04:54:26PM +0800, Jason Wang wrote: >> 在 2021/6/2 上午1:31, Jason Gunthorpe 写道: >>> On Tue, Jun 01, 2021 at 04:47:15PM +0800, Jason Wang wrote: >>>> We can open up to ~0U file descriptors, I don't see why we need to restrict >>>> it in uAPI. >>> There are significant problems with such large file descriptor >>> tables. High FD numbers man things like select don't work at all >>> anymore and IIRC there are more complications. >> >> I don't see how much difference for IOASID and other type of fds. People can >> choose to use poll or epoll. > Not really, once one thing in an applicate uses a large number FDs the > entire application is effected. If any open() can return 'very big > number' then nothing in the process is allowed to ever use select. > > It is not a trivial thing to ask for > >> And with the current proposal, (assuming there's a N:1 ioasid to ioasid). I >> wonder how select can work for the specific ioasid. > pagefault events are one thing that comes to mind. Bundling them all > together into a single ring buffer is going to be necessary. Multifds > just complicate this too > > Jason
Well, this sounds like a re-invention of io_uring which has already worked for multifds.
Thanks
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