On 4 October 2026 00:43:48 BST, "Paul E. McKenney" <[email protected]> wrote: >On Sat, Oct 03, 2026 at 06:52:44PM +0100, Bradley Morgan wrote: >> On 3 October 2026 17:17:19 BST, Kunwu Chan <[email protected]> wrote: >> >Add support for scaling atomic SRCU grace periods using >> >srcu_read_lock_atomic()/srcu_read_unlock_atomic() and >> >synchronize_srcu_atomic(). >> > >> >Suggested-by: Paul E. McKenney <[email protected]> >> >Signed-off-by: Kunwu Chan <[email protected]> >> >> 1: why didn't u cc me >> 2: why did you ommit my tag? I tend to review based on correctness, cuz >idk pauls preferences, once I do I'll be a better rcu reviewer. > >Take it easy, Bradley. > >Many in the Linux kernel community consider it polite to drop a tag >from (or, as in this case, avoid adding a tag to) a patch that changed >significantly. On the CC issue, you did find the patch the first time >without him CCing you. ;-) > >Kunwu did nothing wrong here.
I'm annoyed but not mad, no grudges taken.. > > Thanx, Paul > >> >--- >> >Changes since v1: >> >- Rename srcu_atomic_ctlp to srcua and reuse srcu_ctlp for >> > SRCU operations, as suggested by Paul. >> >- Reuse the existing SRCU cleanup and completed helpers by >> > initializing srcu_ctlp in srcu_atomic_scale_init(). >> >- Add .stats using srcu_scale_stats(). >> >- Use "srcua" to match the existing "srcu" and "srcud" scale >> > type names. >> >- Use synchronize_srcu_atomic() for both normal and expedited >> > scale tests. >> > >> >v1: >https://lore.kernel.org/all/[email protected]/ >> >Tested with kvm.sh --torture rcuscale scale_type=srcua on x86_64 and >> >arm64, alongside gp_exp=1 and PROVE_LOCKING=y: no warnings or lockdep >> >splats. >> >--- >> > kernel/rcu/rcuscale.c | 41 ++++++++++++++++++++++++++++++++++++++++- >> > 1 file changed, 40 insertions(+), 1 deletion(-) >> > >> >diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c >> >index 1097ec15879c..b172882824ac 100644 >> >--- a/kernel/rcu/rcuscale.c >> >+++ b/kernel/rcu/rcuscale.c >> >@@ -293,6 +293,44 @@ static struct rcu_scale_ops srcud_ops = { >> > .name = "srcud" >> > }; >> > >> >+static struct srcu_struct srcua; >> >+ >> >+static int srcu_scale_atomic_read_lock(void) >> >+{ >> >+ return srcu_read_lock_atomic(srcu_ctlp); >> >+} >> >+ >> >+static void srcu_scale_atomic_read_unlock(int idx) >> >+{ >> >+ srcu_read_unlock_atomic(srcu_ctlp, idx); >> >+} >> >+ >> >+static void srcu_scale_atomic_synchronize(void) >> >+{ >> >+ synchronize_srcu_atomic(srcu_ctlp); >> >+} >> >+ >> >+static void srcu_atomic_scale_init(void) >> >+{ >> >+ srcu_ctlp = &srcua; >> >+ init_srcu_struct_atomic(srcu_ctlp); >> >+} >> >+ >> >+static struct rcu_scale_ops srcua_ops = { >> >+ .ptype = SRCU_FLAVOR, >> >+ .init = srcu_atomic_scale_init, >> >+ .cleanup = srcu_sync_scale_cleanup, >> >+ .readlock = srcu_scale_atomic_read_lock, >> >+ .readunlock = srcu_scale_atomic_read_unlock, >> >+ .get_gp_seq = srcu_scale_completed, >> >+ .gp_diff = rcu_seq_diff, >> >+ .exp_completed = srcu_scale_completed, >> >+ .sync = srcu_scale_atomic_synchronize, >> >+ .exp_sync = srcu_scale_atomic_synchronize, >> >+ .stats = srcu_scale_stats, >> >+ .name = "srcua" >> >+}; >> >+ >> > #ifdef CONFIG_TASKS_RCU >> > >> > /* >> >@@ -1110,7 +1148,8 @@ rcu_scale_init(void) >> > long i; >> > long j; >> > static struct rcu_scale_ops *scale_ops[] = { >> >- &rcu_ops, &srcu_ops, &srcud_ops, TASKS_OPS TASKS_RUDE_OPS >> >TASKS_TRACING_OPS >> >+ &rcu_ops, &srcu_ops, &srcua_ops, &srcud_ops, >> >+ TASKS_OPS TASKS_RUDE_OPS TASKS_TRACING_OPS >> > }; >> > >> > if (!torture_init_begin(scale_type, verbose)) >> > >> >base-commit: d21906b0aa1e9573cdb5e7acaca44966b9d1dcd2 >> > >> >> --- Thanks! >> "I'm not a very positive person" - Linus torvalds --- Thanks! "I'm not a very positive person" - Linus torvalds
