| Message ID | 20221024165421.GA1246679@paulmck-ThinkPad-P17-Gen-1 (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 6e442d06621f2af87fc0bf352976694db547c780 |
| Headers | show |
| Series | [GIT,PULL] Keep synchronize_rcu() from enabling irqs in early boot | expand |
On Mon, Oct 24, 2022 at 9:54 AM Paul E. McKenney <paulmck@kernel.org> 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.. Linus
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@kernel.org> 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(-)
On Mon, Oct 24, 2022 at 1:04 PM Paul E. McKenney <paulmck@kernel.org> wrote: > > Please accept my apologies for my confusion! > > Please see below for a pull request for a better-formatted commit. Oh, it was such a small nit that I already pulled your tree - my note was really just a "not a big deal, but in the future it would be nice if.." Linus
The pull request you sent on Mon, 24 Oct 2022 09:54:21 -0700:
> git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git tags/rcu-urgent.2022.10.20a
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/f6602a97a11a3ddc077889fec2c026113c33c670
Thank you!
On Mon, Oct 24, 2022 at 01:06:12PM -0700, Linus Torvalds wrote: > On Mon, Oct 24, 2022 at 1:04 PM Paul E. McKenney <paulmck@kernel.org> wrote: > > > > Please accept my apologies for my confusion! > > > > Please see below for a pull request for a better-formatted commit. > > Oh, it was such a small nit that I already pulled your tree - my note > was really just a "not a big deal, but in the future it would be nice > if.." Thank you, and at least I got practice for the future. ;-) Thanx, Paul
Hello, Linus, 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.2022.10.20a for you to fetch changes up to 31d8aaa87fcef1be5932f3813ea369e21bd3b11d: rcu: Keep synchronize_rcu() from enabling irqs in early boot (2022-10-20 15:34:49 -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(-)