Messages in this thread | | | From | Arnd Bergmann <> | Date | Wed, 13 Oct 2021 21:37:01 +0200 | Subject | Re: [PATCH v2 05/11] sched,livepatch: Use wake_up_if_idle() |
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On Wed, Sep 29, 2021 at 6:10 PM Peter Zijlstra <peterz@infradead.org> wrote: > > Make sure to prod idle CPUs so they call klp_update_patch_state(). > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > kernel/livepatch/transition.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > --- a/kernel/livepatch/transition.c > +++ b/kernel/livepatch/transition.c > @@ -413,8 +413,11 @@ void klp_try_complete_transition(void) > for_each_possible_cpu(cpu) { > task = idle_task(cpu); > if (cpu_online(cpu)) { > - if (!klp_try_switch_task(task)) > + if (!klp_try_switch_task(task)) { > complete = false; > + /* Make idle task go through the main loop. */ > + wake_up_if_idle(cpu); > + }
This caused a build regression on non-SMP kernels:
x86_64-linux-ld: kernel/livepatch/transition.o: in function `klp_try_complete_transition': transition.c:(.text+0x106e): undefined reference to `wake_up_if_idle'
Maybe add a IS_ENABLED(CONFIG_SMP) check to one of the if() conditions?
Arnd
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