On Mon, Oct 24, 2022 at 12:40:01PM -0700, Linus Torvalds wrote:
> On Mon, Oct 24, 2022 at 9:54 AM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
> >
> > This pull request contains a commit that fixes bf95b2bc3e42 ("rcu: Switch
> > polled grace-period APIs to ->gp_seq_polled"), which could incorrectly
> > leave interrupts enabled after an early-boot call to synchronize_rcu().
>
> Minor stylistic nit-pick - please try to keep the commit tags
> together, ie the "Fixes:" tags goes with Reported-by: tags and
> sign-offs etc..
Please accept my apologies for my confusion!
Please see below for a pull request for a better-formatted commit.
Thanx, Paul
------------------------------------------------------------------------
This pull request fixes a merge-window regression noted by Steve Rostedt.
The following changes since commit 9abf2313adc1ca1b6180c508c25f22f9395cc780:
Linux 6.1-rc1 (2022-10-16 15:36:24 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git tags/rcu-urgent.2022.10.24a
for you to fetch changes up to c216e5557395092a1a30ddb2be8ab924b0364585:
rcu: Keep synchronize_rcu() from enabling irqs in early boot (2022-10-24 12:55:37 -0700)
----------------------------------------------------------------
Urgent RCU pull request for v6.1
This pull request contains a commit that fixes bf95b2bc3e42 ("rcu: Switch
polled grace-period APIs to ->gp_seq_polled"), which could incorrectly
leave interrupts enabled after an early-boot call to synchronize_rcu().
Such synchronize_rcu() calls must acquire leaf rcu_node locks in order to
properly interact with polled grace periods, but the code did not take
into account the possibility of synchronize_rcu() being invoked from
the portion of the boot sequence during which interrupts are disabled.
This commit therefore switches the lock acquisition and release from
irq to irqsave/irqrestore.
----------------------------------------------------------------
Paul E. McKenney (1):
rcu: Keep synchronize_rcu() from enabling irqs in early boot
kernel/rcu/tree.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
