On 1/23/25 18:48, Joanne Koong wrote: > On Thu, Jan 23, 2025 at 9:19 AM Bernd Schubert > <bernd.schubert@xxxxxxxxxxx> wrote: >> >> Hi Joanne, >> >>>>> Thanks, applied and pushed with some cleanups including Luis's clamp idea. >>>> >>>> Hi Miklos, >>>> >>>> I don't think the timeouts do work with io-uring yet, I'm not sure >>>> yet if I have time to work on that today or tomorrow (on something >>>> else right now, I can try, but no promises). >>> >>> Hi Bernd, >>> >>> What are your thoughts on what is missing on the io-uring side for >>> timeouts? If a request times out, it will abort the connection and >>> AFAICT, the abort logic should already be fine for io-uring, as users >>> can currently abort the connection through the sysfs interface and >>> there's no internal difference in aborting through sysfs vs timeouts. >>> >> >> in fuse_check_timeout() it iterates over each fud and then fpq. >> In dev_uring.c fpq is is per queue but unrelated to fud. In current >> fuse-io-uring fud is not cloned anymore - using fud won't work. >> And Requests are also not queued at all on the other list >> fuse_check_timeout() is currently checking. > > In the io-uring case, there still can be fuds and their associated > fpqs given that /dev/fuse can be used still, no? So wouldn't the > io-uring case still need this logic in fuse_check_timeout() for > checking requests going through /dev/fuse? Yes, these need to be additionally checked. > >> >> Also, with a ring per core, maybe better to use >> a per queue check that is core bound? I.e. zero locking overhead? > > How do you envision a queue check that bypasses grabbing the > queue->lock? The timeout handler could be triggered on any core, so > I'm not seeing how it could be core bound. I don't want to bypass it, but maybe each queue could have its own workq and timeout checker? And then use queue_delayed_work_on()? > >> And I think we can also avoid iterating over hash lists (queue->fpq), >> but can use the 'ent_in_userspace' list. >> >> We need to iterate over these other entry queues anyway: >> >> ent_w_req_queue >> fuse_req_bg_queue >> ent_commit_queue >> > > Why do we need to iterate through the ent lists (ent_w_req_queue and > ent_commit_queue)? AFAICT, in io-uring a request is either on the > fuse_req_queue/fuse_req_bg_queue or on the fpq->processing list. Even > when an entry has been queued to ent_w_req_queue or ent_commit_queue, > the request itself is still queued on > fuse_req_queue/fuse_req_bg_queue/fpq->processing. I'm not sure I > understand why we still need to look at the ent lists? Yeah you are right, we could avoid ent_w_req_queue and ent_commit_queue if we use fpq->processing, but processing consists of 256 lists - overhead is much smaller by using the entry lists? > >> >> And we also need to iterate over >> >> fuse_req_queue >> fuse_req_bg_queue > > Why do we need to iterate through fuse_req_queue and > fuse_req_bg_queue? fuse_uring_request_expired() checks the head of > fuse_req_queue and fuse_req_bg_queue and given that requests are added > to fuse_req_queue/fuse_req_bg_queue sequentially (eg added to the tail > of these lists), why isn't this enough? I admit I'm a bit lost with that question. Aren't you pointing out the same lists as I do? > > > If it's helpful, I can resubmit this patch series so that the io-uring > changes are isolated to its own patch (eg have patch 1 and 2 from the > original series and then have patch 3 be the io-uring changes). Sounds good to me. Thanks, Bernd
