From: Shaohua Li Date: Tue, 13 Dec 2005 06:17:08 +0000 (-0800) Subject: [PATCH] i386/x86-64 disable LAPIC completely for offline CPU X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5e9ef02ec00c70840661d174dc2f4862db471bb6;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git [PATCH] i386/x86-64 disable LAPIC completely for offline CPU Disabling LAPIC timer isn't sufficient. In some situations, such as we enabled NMI watchdog, there is still unexpected interrupt (such as NMI) invoked in offline CPU. This also avoids offline CPU receives spurious interrupt and anything similar. Signed-off-by: Shaohua Li Signed-off-by: Andi Kleen Acked-by: "Seth, Rohit" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c index d16520da4550..9ed449af8e9f 100644 --- a/arch/i386/kernel/smpboot.c +++ b/arch/i386/kernel/smpboot.c @@ -1338,8 +1338,7 @@ int __cpu_disable(void) if (cpu == 0) return -EBUSY; - /* We enable the timer again on the exit path of the death loop */ - disable_APIC_timer(); + clear_local_APIC(); /* Allow any queued timer interrupts to get serviced */ local_irq_enable(); mdelay(1); diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c index 683c33f7b967..ecbd7b83acc1 100644 --- a/arch/x86_64/kernel/smpboot.c +++ b/arch/x86_64/kernel/smpboot.c @@ -1181,7 +1181,7 @@ int __cpu_disable(void) if (cpu == 0) return -EBUSY; - disable_APIC_timer(); + clear_local_APIC(); /* * HACK: