Messages in this thread | | | Date | Thu, 27 Sep 2018 10:48:17 +0200 | From | Greg KH <> | Subject | Re: [PATCH stable] tick/nohz: Prevent bogus softirq pending warning |
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On Thu, Sep 27, 2018 at 10:07:39AM +0200, Geert Uytterhoeven wrote: > Hi Greg, > > On Wed, Sep 12, 2018 at 3:56 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > 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> > > This issue is still present in v4.14.72. Can you please apply Thomas' fix?
Oops, sorry for the delay, now queued up.
greg k-h
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