diff mbox series

[1/6] x86/smp: Remove pointless wmb() from native_stop_other_cpus()

Message ID 20230603200459.657036052@linutronix.de
State New
Headers
Series Cure kexec() vs. mwait_play_dead() troubles |

Commit Message

Thomas Gleixner June 3, 2023, 8:06 p.m. UTC 
  The wmb() after the successfull atomic_cmpxchg() is complete voodoo along
with the comment stating "sync above data before sending IRQ".

There is no "above" data except for the atomic_t stopping_cpu which has
just been acquired. The reboot IPI handler does not check any data and
unconditionally disables the CPU.

Remove this cargo cult barrier.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/smp.c |    3 ---
 1 file changed, 3 deletions(-)
diff mbox series

Patch

--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -171,9 +171,6 @@  static void native_stop_other_cpus(int w
 		if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1)
 			return;
 
-		/* sync above data before sending IRQ */
-		wmb();
-
 		apic_send_IPI_allbutself(REBOOT_VECTOR);
 
 		/*