diff options
Diffstat (limited to 'arch/x86/kernel/smp.c')
| -rw-r--r-- | arch/x86/kernel/smp.c | 39 |
1 files changed, 7 insertions, 32 deletions
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 6eb06d001bcc..96a771f9f930 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -131,7 +131,7 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs) } /* - * Disable virtualization, APIC etc. and park the CPU in a HLT loop + * this function calls the 'stop' function on all other CPUs in the system. */ DEFINE_IDTENTRY_SYSVEC(sysvec_reboot) { @@ -172,17 +172,13 @@ static void native_stop_other_cpus(int wait) * 2) Wait for all other CPUs to report that they reached the * HLT loop in stop_this_cpu() * - * 3) If the system uses INIT/STARTUP for CPU bringup, then - * send all present CPUs an INIT vector, which brings them - * completely out of the way. + * 3) If #2 timed out send an NMI to the CPUs which did not + * yet report * - * 4) If #3 is not possible and #2 timed out send an NMI to the - * CPUs which did not yet report - * - * 5) Wait for all other CPUs to report that they reached the + * 4) Wait for all other CPUs to report that they reached the * HLT loop in stop_this_cpu() * - * #4 can obviously race against a CPU reaching the HLT loop late. + * #3 can obviously race against a CPU reaching the HLT loop late. * That CPU will have reported already and the "have all CPUs * reached HLT" condition will be true despite the fact that the * other CPU is still handling the NMI. Again, there is no @@ -198,7 +194,7 @@ static void native_stop_other_cpus(int wait) /* * Don't wait longer than a second for IPI completion. The * wait request is not checked here because that would - * prevent an NMI/INIT shutdown in case that not all + * prevent an NMI shutdown attempt in case that not all * CPUs reach shutdown state. */ timeout = USEC_PER_SEC; @@ -206,27 +202,7 @@ static void native_stop_other_cpus(int wait) udelay(1); } - /* - * Park all other CPUs in INIT including "offline" CPUs, if - * possible. That's a safe place where they can't resume execution - * of HLT and then execute the HLT loop from overwritten text or - * page tables. - * - * The only downside is a broadcast MCE, but up to the point where - * the kexec() kernel brought all APs online again an MCE will just - * make HLT resume and handle the MCE. The machine crashes and burns - * due to overwritten text, page tables and data. So there is a - * choice between fire and frying pan. The result is pretty much - * the same. Chose frying pan until x86 provides a sane mechanism - * to park a CPU. - */ - if (smp_park_other_cpus_in_init()) - goto done; - - /* - * If park with INIT was not possible and the REBOOT_VECTOR didn't - * take all secondary CPUs offline, try with the NMI. - */ + /* if the REBOOT_VECTOR didn't work, try with the NMI */ if (!cpumask_empty(&cpus_stop_mask)) { /* * If NMI IPI is enabled, try to register the stop handler @@ -249,7 +225,6 @@ static void native_stop_other_cpus(int wait) udelay(1); } -done: local_irq_save(flags); disable_local_APIC(); mcheck_cpu_clear(this_cpu_ptr(&cpu_info)); |