Re: uprobe splat in PREEMP_RT

Oleg Nesterov
2025-04-03T12:44:45Z

On 04/03, Oleg Nesterov wrote:
>
> From include/linux/seqlock.h
>
> SEQCOUNT_LOCKNAME(raw_spinlock, raw_spinlock_t, false, raw_spin)
> SEQCOUNT_LOCKNAME(spinlock, spinlock_t, __SEQ_RT, spin)
> SEQCOUNT_LOCKNAME(rwlock, rwlock_t, __SEQ_RT, read)
> SEQCOUNT_LOCKNAME(mutex, struct mutex, true, mutex)
>
> so for these seqcount's seqprop_preemptible() returns false only if
> the associated lock disables preemption. raw_spinlock always does this
> spinlock/rwlock depend on PREEMPT_RT.

Sorry, I wasn't clear... seqprop_preemptible() always returns false
on PREEMPT_RT, I meant the "preemptible" check in seqprop_sequence().

Oleg.