Re: [PATCH] s390/idle: Fix suspicious RCU usage

2020-10-08 Thread Sven Schnelle
Hi Peter, Peter Zijlstra writes: > On Wed, Oct 07, 2020 at 12:05:51PM +0200, Peter Zijlstra wrote: >> On Wed, Oct 07, 2020 at 09:53:25AM +0200, Sven Schnelle wrote: >> > Hi Peter, >> > >> > pet...@infradead.org writes: >> > >> > > After commit eb1f00237aca ("lockdep,trace: Expose

Re: [PATCH] s390/idle: Fix suspicious RCU usage

2020-10-07 Thread Peter Zijlstra
On Wed, Oct 07, 2020 at 12:05:51PM +0200, Peter Zijlstra wrote: > On Wed, Oct 07, 2020 at 09:53:25AM +0200, Sven Schnelle wrote: > > Hi Peter, > > > > pet...@infradead.org writes: > > > > > After commit eb1f00237aca ("lockdep,trace: Expose tracepoints") the > > > lock tracepoints are visible to

Re: [PATCH] s390/idle: Fix suspicious RCU usage

2020-10-07 Thread Peter Zijlstra
On Wed, Oct 07, 2020 at 09:53:25AM +0200, Sven Schnelle wrote: > Hi Peter, > > pet...@infradead.org writes: > > > After commit eb1f00237aca ("lockdep,trace: Expose tracepoints") the > > lock tracepoints are visible to lockdep and RCU-lockdep is finding a > > bunch more RCU violations that were

Re: [PATCH] s390/idle: Fix suspicious RCU usage

2020-10-07 Thread Sven Schnelle
Hi Peter, pet...@infradead.org writes: > After commit eb1f00237aca ("lockdep,trace: Expose tracepoints") the > lock tracepoints are visible to lockdep and RCU-lockdep is finding a > bunch more RCU violations that were previously hidden. > > Switch the idle->seqcount over to using raw_write_*()

[PATCH] s390/idle: Fix suspicious RCU usage

2020-09-08 Thread peterz
After commit eb1f00237aca ("lockdep,trace: Expose tracepoints") the lock tracepoints are visible to lockdep and RCU-lockdep is finding a bunch more RCU violations that were previously hidden. Switch the idle->seqcount over to using raw_write_*() to avoid the lockdep annotation and thus the lock

Re: [PATCH] s390/idle: Fix suspicious RCU usage

2020-09-08 Thread Heiko Carstens
On Tue, Sep 08, 2020 at 03:30:31PM +0200, pet...@infradead.org wrote: > > After commit eb1f00237aca ("lockdep,trace: Expose tracepoints") the > lock tracepoints are visible to lockdep and RCU-lockdep is finding a > bunch more RCU violations that were previously hidden. > > Switch the