On Tue, Jun 05, 2018 at 04:20:51PM +0200, Greg Kroah-Hartman wrote: > I think Peter Hurley was just trying to hid the atomic mess behind > function calls, which is why he didn't open-code it like you did here.
No reason to then not use the right types though. I mean, you can still use the helper functions, but I figured they weren't worth the bother. Esp. then using try_cmpxchg (which is relatively new) the helpers became very thin. > But this makes it a bit more obvious as to what "magic" is happening, so > I like it. Well, it also fixes one additional bug in that the old code used a regular unsigned long load of the value: - long count = sem->count; + long count = atomic_long_read(&sem->count); which doesn't guarantee enough. The atomic_long_read() thing implies READ_ONCE() which ensures the load is single copy atomic (GCC used to guarantee that for regular loads/stores to naturally aligned native words, but no longer). > Care to turn it into a real patch so I can queue it up after 4.18-rc1 is > out? Or do you want me to do that? I can make a proper patch, hold on.
