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| author | Aaron Tomlin <atomlin@redhat.com> | 2014-06-23 13:22:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-23 16:47:44 -0700 |
| commit | f3aca3d09525f87731ba6b892c9b010570bc54b4 (patch) | |
| tree | 80c80be186f7bac74cb548444562ae6890938d83 /arch/x86 | |
| parent | 88e15ce402c58f41037752da092683e90826742a (diff) | |
| download | linux-f3aca3d09525f87731ba6b892c9b010570bc54b4.tar.gz | |
nmi: provide the option to issue an NMI back trace to every cpu but current
Sometimes it is preferred not to use the trigger_all_cpu_backtrace() routine when one wants to avoid capturing a back trace for current. For instance if one was previously captured recently. This patch provides a new routine namely trigger_allbutself_cpu_backtrace() which offers the flexibility to issue an NMI to every cpu but current and capture a back trace accordingly. Patch x86 and sparc to support new routine. [dzickus@redhat.com: add stub in #else clause] [dzickus@redhat.com: don't print message in single processor case, wrap with get/put_cpu based on Oleg's suggestion] [sfr@canb.auug.org.au: undo C99ism] Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/irq.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/hw_nmi.c | 18 |
2 files changed, 15 insertions, 5 deletions
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h index cb6cfcd034cf..a80cbb88ea91 100644 --- a/arch/x86/include/asm/irq.h +++ b/arch/x86/include/asm/irq.h @@ -43,7 +43,7 @@ extern int vector_used_by_percpu_irq(unsigned int vector); extern void init_ISA_irqs(void); #ifdef CONFIG_X86_LOCAL_APIC -void arch_trigger_all_cpu_backtrace(void); +void arch_trigger_all_cpu_backtrace(bool); #define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace #endif diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index c3fcb5de5083..6a1e71bde323 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -33,31 +33,41 @@ static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly; /* "in progress" flag of arch_trigger_all_cpu_backtrace */ static unsigned long backtrace_flag; -void arch_trigger_all_cpu_backtrace(void) +void arch_trigger_all_cpu_backtrace(bool include_self) { int i; + int cpu = get_cpu(); - if (test_and_set_bit(0, &backtrace_flag)) + if (test_and_set_bit(0, &backtrace_flag)) { /* * If there is already a trigger_all_cpu_backtrace() in progress * (backtrace_flag == 1), don't output double cpu dump infos. */ + put_cpu(); return; + } cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask); + if (!include_self) + cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask)); - printk(KERN_INFO "sending NMI to all CPUs:\n"); - apic->send_IPI_all(NMI_VECTOR); + if (!cpumask_empty(to_cpumask(backtrace_mask))) { + pr_info("sending NMI to %s CPUs:\n", + (include_self ? "all" : "other")); + apic->send_IPI_mask(to_cpumask(backtrace_mask), NMI_VECTOR); + } /* Wait for up to 10 seconds for all CPUs to do the backtrace */ for (i = 0; i < 10 * 1000; i++) { if (cpumask_empty(to_cpumask(backtrace_mask))) break; mdelay(1); + touch_softlockup_watchdog(); } clear_bit(0, &backtrace_flag); smp_mb__after_atomic(); + put_cpu(); } static int |