diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2020-11-13 09:37:39 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-03 10:09:29 +0200 |
| commit | 641e1d88404a57983c75cc39b9feb076f5cdeac8 (patch) | |
| tree | 10db2f873d10c6240deb4a20af5c635a94820be6 /kernel | |
| parent | f789de3be808a0492a09cd7ad44cb017203572c6 (diff) | |
srcu: Provide internal interface to start a Tiny SRCU grace period
commit 1a893c711a600ab57526619b56e6f6b7be00956e upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -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 6208c1dae5c9..ee25b365c3ea 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -151,6 +151,16 @@ 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. @@ -166,12 +176,7 @@ 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); |