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authorThomas Gleixner <tglx@linutronix.de>2020-02-25 14:55:15 +0100
committerBorislav Petkov <bp@suse.de>2020-02-25 21:21:44 +0100
commitd364847eed890211444ad74496bb549f838c6018 (patch)
tree98351e626862f649d85d13ea7ebbbf98304ef1d1 /arch/x86
parentLinux 5.6-rc3 (diff)
downloadlinux-dev-d364847eed890211444ad74496bb549f838c6018.tar.xz
linux-dev-d364847eed890211444ad74496bb549f838c6018.zip
x86/mce/therm_throt: Undo thermal polling properly on CPU offline
Chris Wilson reported splats from running the thermal throttling workqueue callback on offlined CPUs. The problem is that that callback should not even run on offlined CPUs but it happens nevertheless because the offlining callback thermal_throttle_offline() does not symmetrically undo the setup work done in its onlining counterpart. IOW, 1. The thermal interrupt vector should be masked out before ... 2. ... cancelling any pending work synchronously so that no new work is enqueued anymore. Do those things and fix the issue properly. [ bp: Write commit message. ] Fixes: f6656208f04e ("x86/mce/therm_throt: Optimize notifications of thermal throttle") Reported-by: Chris Wilson <chris@chris-wilson.co.uk> Tested-by: Pandruvada, Srinivas <srinivas.pandruvada@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/158120068234.18291.7938335950259651295@skylake-alporthouse-com
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/cpu/mce/therm_throt.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/mce/therm_throt.c b/arch/x86/kernel/cpu/mce/therm_throt.c
index 58b4ee3cda77..f36dc0742085 100644
--- a/arch/x86/kernel/cpu/mce/therm_throt.c
+++ b/arch/x86/kernel/cpu/mce/therm_throt.c
@@ -486,9 +486,14 @@ static int thermal_throttle_offline(unsigned int cpu)
{
struct thermal_state *state = &per_cpu(thermal_state, cpu);
struct device *dev = get_cpu_device(cpu);
+ u32 l;
+
+ /* Mask the thermal vector before draining evtl. pending work */
+ l = apic_read(APIC_LVTTHMR);
+ apic_write(APIC_LVTTHMR, l | APIC_LVT_MASKED);
- cancel_delayed_work(&state->package_throttle.therm_work);
- cancel_delayed_work(&state->core_throttle.therm_work);
+ cancel_delayed_work_sync(&state->package_throttle.therm_work);
+ cancel_delayed_work_sync(&state->core_throttle.therm_work);
state->package_throttle.rate_control_active = false;
state->core_throttle.rate_control_active = false;