Re: [PATCH tip/core/rcu 02/26] mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls

2020-06-23 Thread Joel Fernandes
On Tue, Jun 23, 2020 at 01:55:08PM -0700, Paul E. McKenney wrote: [..] > > Just for my understanding, cond_resched_tasks_rcu_qs() may not help here > > because preemption is not disabled right? Still I see no harm in using it > > here either as it may give a slight speed up for tasks-RCU. > >

Re: [PATCH tip/core/rcu 02/26] mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls

2020-06-23 Thread Paul E. McKenney
On Tue, Jun 23, 2020 at 03:34:31PM -0400, Joel Fernandes wrote: > On Mon, Jun 22, 2020 at 05:21:23PM -0700, paul...@kernel.org wrote: > > From: "Paul E. McKenney" > > > > A large process running on a heavily loaded system can encounter the > > following RCU CPU stall warning: > > > > rcu:

Re: [PATCH tip/core/rcu 02/26] mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls

2020-06-23 Thread Joel Fernandes
On Mon, Jun 22, 2020 at 05:21:23PM -0700, paul...@kernel.org wrote: > From: "Paul E. McKenney" > > A large process running on a heavily loaded system can encounter the > following RCU CPU stall warning: > > rcu: INFO: rcu_sched self-detected stall on CPU > rcu: \x093-: (20998 ticks this

Re: [PATCH tip/core/rcu 02/26] mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls

2020-06-22 Thread Paul E. McKenney
On Mon, Jun 22, 2020 at 05:47:19PM -0700, Shakeel Butt wrote: > On Mon, Jun 22, 2020 at 5:22 PM wrote: > > > > From: "Paul E. McKenney" > > > > A large process running on a heavily loaded system can encounter the > > following RCU CPU stall warning: > > > > rcu: INFO: rcu_sched self-detected

Re: [PATCH tip/core/rcu 02/26] mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls

2020-06-22 Thread Shakeel Butt
On Mon, Jun 22, 2020 at 5:22 PM wrote: > > From: "Paul E. McKenney" > > A large process running on a heavily loaded system can encounter the > following RCU CPU stall warning: > > rcu: INFO: rcu_sched self-detected stall on CPU > rcu: \x093-: (20998 ticks this GP)