Hi Thomas,

On Thu, Aug 30, 2018 at 5:06 PM Thomas Gleixner [off-list ref] 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 <redacted>
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