Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Wed, 12 Sep 2018 15:56:04 +0200 | Subject | Re: [PATCH stable] tick/nohz: Prevent bogus softirq pending warning |
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Hi Thomas,
On Thu, Aug 30, 2018 at 5:06 PM Thomas Gleixner <tglx@linutronix.de> wrote: > Commit 0a0e0829f990 ("nohz: Fix missing tick reprogram when interrupting an > inline softirq") got backported to stable trees and now causes the NOHZ > softirq pending warning to trigger. It's not an upstream issue as the NOHZ > update logic has been changed there. > > The problem is when a softirq disabled section gets interrupted and on > return from interrupt the tick/nohz state is evaluated, which then can > observe pending soft interrupts. These soft interrupts are legitimately > pending because they cannot be processed as long as soft interrupts are > disabled and the interrupted code will correctly process them when soft > interrupts are reenabled. > > Add a check for softirqs disabled to the pending check to prevent the > warning. > > Reported-by: Grygorii Strashko <grygorii.strashko@ti.com> > Reported-by: John Crispin <john@phrozen.org> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Tested-by: Grygorii Strashko <grygorii.strashko@ti.com> > Tested-by: John Crispin <john@phrozen.org> > Cc: Frederic Weisbecker <frederic@kernel.org> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Anna-Maria Gleixner <anna-maria@linutronix.de> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: stable@vger.kernel.org
Fixes: 2d898915ccf4838c ("nohz: Fix missing tick reprogram when interrupting an inline softirq")
Issue in v4.14.x bisected to the above commit, and fixed by your patch.
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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