On Wednesday 24 March 2010, Jiri Slaby wrote: > On 03/24/2010 09:42 PM, Pavel Machek wrote: > >> + if (test_bit(TODO_CLOSED, to_do_flags)) > >> + return -EIO; > >> + > >> + to_do_buf = buf; > >> + wmb(); > >> + set_bit(TODO_WORK, to_do_flags); > >> + wake_up_interruptible(&to_do_wait); > > > > Uhuh, open-coded barriers... these need to be commented, and I guess > > you just should not play this kind of trickery. > > It's just to ensure the to_do_buf store is not reordered with the > set_bit. I wanted to avoid locks as too heavy tools here. No, please use them, at least in a prototype version. We can always optimize things out later, but doing optimizations upfront doesn't really work well from my experience. So, if you'd use a lock somewhere, please use it, or maybe use a completion if that fits the design better. In the majority of cases it's not as heavy wieght as it seems at first sight. Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
