diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2020-11-13 18:37:39 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-01-04 22:53:37 +0100 |
| commit | 1a893c711a600ab57526619b56e6f6b7be00956e (patch) | |
| tree | 773590705c0b5e063b65863011368b3a66643cb2 | |
| parent | srcu: Make Tiny SRCU use multi-bit grace-period counter (diff) | |
| download | linux-1a893c711a600ab57526619b56e6f6b7be00956e.tar.xz linux-1a893c711a600ab57526619b56e6f6b7be00956e.zip | |
srcu: Provide internal interface to start a Tiny SRCU grace period
There is a need for a polling interface for SRCU grace periods.
This polling needs to initiate an SRCU grace period without
having to queue (and manage) a callback. This commit therefore
splits the Tiny SRCU call_srcu() function into callback-queuing and
start-grace-period portions, with the latter in a new function named
srcu_gp_start_if_needed().
Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| -rw-r--r-- | kernel/rcu/srcutiny.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 5598cf6f1edc..3bac1db85a85 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -152,6 +152,16 @@ void srcu_drive_gp(struct work_struct *wp) } EXPORT_SYMBOL_GPL(srcu_drive_gp); +static void srcu_gp_start_if_needed(struct srcu_struct *ssp) +{ + if (!READ_ONCE(ssp->srcu_gp_running)) { + if (likely(srcu_init_done)) + schedule_work(&ssp->srcu_work); + else if (list_empty(&ssp->srcu_work.entry)) + list_add(&ssp->srcu_work.entry, &srcu_boot_list); + } +} + /* * Enqueue an SRCU callback on the specified srcu_struct structure, * initiating grace-period processing if it is not already running. @@ -167,12 +177,7 @@ void call_srcu(struct srcu_struct *ssp, struct rcu_head *rhp, *ssp->srcu_cb_tail = rhp; ssp->srcu_cb_tail = &rhp->next; local_irq_restore(flags); - if (!READ_ONCE(ssp->srcu_gp_running)) { - if (likely(srcu_init_done)) - schedule_work(&ssp->srcu_work); - else if (list_empty(&ssp->srcu_work.entry)) - list_add(&ssp->srcu_work.entry, &srcu_boot_list); - } + srcu_gp_start_if_needed(ssp); } EXPORT_SYMBOL_GPL(call_srcu); |