Jan, On Fri, 2 Aug 2019, Jan Kara wrote: > This series is derived from Thomas' series to get rid of bit spinlocks in > buffer head code. These patches convert BH_State bit spinlock to an ordinary > spinlock inside struct journal_head and somewhat reduce the critical section > under BH_JournalHead bit spinlock so that it is fine for RT. Thanks a lot for cleaning this up! > Motivation from original Thomas' series: > > Bit spinlocks are problematic if PREEMPT_RT is enabled. They disable > preemption, which is undesired for latency reasons and breaks when regular > spinlocks are taken within the bit_spinlock locked region because regular > spinlocks are converted to 'sleeping spinlocks' on RT. > > Bit spinlocks are also not covered by lock debugging, e.g. lockdep. With > the spinlock substitution in place, they can be exposed via a new config > switch: CONFIG_DEBUG_BIT_SPINLOCKS. > > WRT patch routing: Since these are non-trivial changes to JBD2 and independent > of the rest of the series from Thomas, I think it would be safest to route > them through ext4 tree where they get most testing. Thoughts? Yes, there is no dependency, so feel free to route it through ext4. Thanks, tglx
