diff options
Diffstat (limited to 'arch/x86/kernel/cpu/bus_lock.c')
| -rw-r--r-- | arch/x86/kernel/cpu/bus_lock.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/bus_lock.c b/arch/x86/kernel/cpu/bus_lock.c index 704e9241b964..97222efb4d2a 100644 --- a/arch/x86/kernel/cpu/bus_lock.c +++ b/arch/x86/kernel/cpu/bus_lock.c @@ -49,7 +49,7 @@ static unsigned int sysctl_sld_mitigate = 1; static DEFINE_SEMAPHORE(buslock_sem, 1); #ifdef CONFIG_PROC_SYSCTL -static struct ctl_table sld_sysctls[] = { +static const struct ctl_table sld_sysctls[] = { { .procname = "split_lock_mitigate", .data = &sysctl_sld_mitigate, @@ -192,7 +192,13 @@ static void __split_lock_reenable(struct work_struct *work) { sld_update_msr(true); } -static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable); +/* + * In order for each CPU to schedule its delayed work independently of the + * others, delayed work struct must be per-CPU. This is not required when + * sysctl_sld_mitigate is enabled because of the semaphore that limits + * the number of simultaneously scheduled delayed works to 1. + */ +static DEFINE_PER_CPU(struct delayed_work, sl_reenable); /* * If a CPU goes offline with pending delayed work to re-enable split lock @@ -213,7 +219,7 @@ static int splitlock_cpu_offline(unsigned int cpu) static void split_lock_warn(unsigned long ip) { - struct delayed_work *work; + struct delayed_work *work = NULL; int cpu; if (!current->reported_split_lock) @@ -235,11 +241,17 @@ static void split_lock_warn(unsigned long ip) if (down_interruptible(&buslock_sem) == -EINTR) return; work = &sl_reenable_unlock; - } else { - work = &sl_reenable; } cpu = get_cpu(); + + if (!work) { + work = this_cpu_ptr(&sl_reenable); + /* Deferred initialization of per-CPU struct */ + if (!work->work.func) + INIT_DELAYED_WORK(work, __split_lock_reenable); + } + schedule_delayed_work_on(cpu, work, 2); /* Disable split lock detection on this CPU to make progress */ |