Re: [PATCH v2 -rcu] srcu: Use rcu_seq_done_exact() for polling API

2025-03-05 Thread Boqun Feng
On Wed, Feb 19, 2025 at 07:43:08AM -0500, Joel Fernandes wrote: > poll_state_synchronize_srcu() uses rcu_seq_done() unlike > poll_state_synchronize_rcu() which uses rcu_seq_done_exact(). > > The rcu_seq_done_exact() makes more sense for polling API, as with > this API, there is a higher chance th

Re: [PATCH v2 -rcu] srcu: Use rcu_seq_done_exact() for polling API

2025-02-19 Thread Kent Overstreet
On Wed, Feb 19, 2025 at 06:45:07PM -0500, Joel Fernandes wrote: > > > On 2/19/2025 4:07 PM, Kent Overstreet wrote: > > On Wed, Feb 19, 2025 at 08:29:47AM -0500, Joel Fernandes wrote: > >> > >> > >> On 2/19/2025 8:22 AM, Paul E. McKenney wrote: > >>> On Wed, Feb 19, 2025 at 07:43:08AM -0500, Joel

Re: [PATCH v2 -rcu] srcu: Use rcu_seq_done_exact() for polling API

2025-02-19 Thread Joel Fernandes
On 2/19/2025 4:07 PM, Kent Overstreet wrote: > On Wed, Feb 19, 2025 at 08:29:47AM -0500, Joel Fernandes wrote: >> >> >> On 2/19/2025 8:22 AM, Paul E. McKenney wrote: >>> On Wed, Feb 19, 2025 at 07:43:08AM -0500, Joel Fernandes wrote: poll_state_synchronize_srcu() uses rcu_seq_done() unlike

Re: [PATCH v2 -rcu] srcu: Use rcu_seq_done_exact() for polling API

2025-02-19 Thread Kent Overstreet
On Wed, Feb 19, 2025 at 08:29:47AM -0500, Joel Fernandes wrote: > > > On 2/19/2025 8:22 AM, Paul E. McKenney wrote: > > On Wed, Feb 19, 2025 at 07:43:08AM -0500, Joel Fernandes wrote: > >> poll_state_synchronize_srcu() uses rcu_seq_done() unlike > >> poll_state_synchronize_rcu() which uses rcu_se

Re: [PATCH v2 -rcu] srcu: Use rcu_seq_done_exact() for polling API

2025-02-19 Thread Joel Fernandes
On 2/19/2025 8:22 AM, Paul E. McKenney wrote: > On Wed, Feb 19, 2025 at 07:43:08AM -0500, Joel Fernandes wrote: >> poll_state_synchronize_srcu() uses rcu_seq_done() unlike >> poll_state_synchronize_rcu() which uses rcu_seq_done_exact(). >> >> The rcu_seq_done_exact() makes more sense for pollin

Re: [PATCH v2 -rcu] srcu: Use rcu_seq_done_exact() for polling API

2025-02-19 Thread Paul E. McKenney
On Wed, Feb 19, 2025 at 07:43:08AM -0500, Joel Fernandes wrote: > poll_state_synchronize_srcu() uses rcu_seq_done() unlike > poll_state_synchronize_rcu() which uses rcu_seq_done_exact(). > > The rcu_seq_done_exact() makes more sense for polling API, as with > this API, there is a higher chance th

[PATCH v2 -rcu] srcu: Use rcu_seq_done_exact() for polling API

2025-02-19 Thread Joel Fernandes
poll_state_synchronize_srcu() uses rcu_seq_done() unlike poll_state_synchronize_rcu() which uses rcu_seq_done_exact(). The rcu_seq_done_exact() makes more sense for polling API, as with this API, there is a higher chance that there is a significant delay between the get_state..() and poll_state..