hi,
On 9/7/20 2:56 AM, Xiaoguang Wang wrote:
3. When it's appropriate to set ctx's IORING_SQ_NEED_WAKEUP flag? In
your current implementation, if a ctx is marked as SQT_IDLE, this ctx
will be set IORING_SQ_NEED_WAKEUP flag, but if other ctxes have work
to do, then io_sq_thread is still running and does not need to be
waken up, then a later wakeup form userspace is unnecessary. I think
it maybe appropriate to set IORING_SQ_NEED_WAKEUP when all ctxes have
no work to do, you can have a look at my attached codes:)
That's a good point, any chance I can get you to submit a patch to fix
that up?
4. Is io_attach_sq_data really safe? sqd_list is a global list, but
its search key is a fd local to process, different processes may have
same fd, then this codes looks odd, seems that your design is to make
io_sq_thread shared inside process.
It's really meant for thread sharing, or you could pass the fd and use
it across a process too. See the incremental I just sent in a reply to
Pavel.
That said, I do think the per-cpu approach has merrit, and I also think
it should be possible to layer it on top of the existing code in
for-5.10/io_uring. So I'd strongly encourage you to try and do that, so
you can get rid of using that private patch and just have it upstream
instead.
Really thanks for your encouragement, I'll do my best to try to have it in upstream.
Regards,
Xiaoguang Wang
