On Wed, Oct 10, 2018 at 11:53 AM, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: > On 2018-10-10 11:45:32 [+0200], Dmitry Vyukov wrote: >> > Should I repost Clark's patch? >> >> >> I am much more comfortable with just changing the type of the lock. > > Yes, that is what Clark's patch does. Should I resent it? Yes. Clark's patch looks good to me. Probably would be useful to add a comment as to why raw spinlock is used (otherwise somebody may refactor it back later). >> What are the bad implications of using the raw spinlock? Will it help >> to do something along the following lines: >> >> // Because of ... >> #if CONFIG_RT >> #define quarantine_spinlock_t raw_spinlock_t >> #else >> #define quarantine_spinlock_t spinlock_t >> #endif > > no. For !RT spinlock_t and raw_spinlock_t are the same. For RT > spinlock_t does not disable interrupts or preemption while > raw_spinlock_t does. > Therefore holding a raw_spinlock_t might increase your latency. Ack.
