On Fri, Jan 26, 2024 at 01:43:25PM -1000, Tejun Heo wrote: > Hello, > > The following is a draft patch which implements atomic workqueues and > convert dm-crypt to use it instead of tasklet. It's an early draft and very > lightly tested but seems to work more or less. It's on top of wq/for6.9 + a > pending patchset. The following git branch can be used for testing. > > git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git wq-atomic-draft > > I'll go over it to make sure all the pieces work. While it adds some > complications, it doesn't seem too bad and conversion from tasklet should be > straightforward too. > > - It hooks into tasklet[_hi] for now but if we get to update all of tasklet > users, we can just repurpose the tasklet softirq slots directly. > > - I thought about allowing busy-waits for flushes and cancels but it didn't > seem necessary. Keeping them blocking has the benefit of avoiding possible > nasty deadlocks. We can revisit if there's need. > > - Compared to tasklet, each work item goes through a bit more management > code because I wanted to keep the code as unified as possible to regular > threaded workqueues. That said, it's not a huge amount and my bet is that > the difference is unlikely to be noticeable. Should have known when it worked too well on the first try but I missed a part in init and this was just running them on per-cpu workqueues. Will post an actually working version later. Thanks. -- tejun
