From f6325e30ebd6fc870315b017a5d4a6ab15bf790b Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:08 -0600 Subject: [PATCH 1/7] cpumask: use cpu_online in kernel/perf_event.c Also, we want to check against nr_cpu_ids, not num_possible_cpus(). The latter works, but the correct bounds check is < nr_cpu_ids. Signed-off-by: Rusty Russell To: Thomas Gleixner --- kernel/perf_event.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 8ab86988bd2..97d1a3dd7a5 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1614,7 +1614,7 @@ static struct perf_event_context *find_get_context(pid_t pid, int cpu) * offline CPU and activate it when the CPU comes up, but * that's for later. */ - if (!cpu_isset(cpu, cpu_online_map)) + if (!cpu_online(cpu)) return ERR_PTR(-ENODEV); cpuctx = &per_cpu(perf_cpu_context, cpu); From 58463c1fe25f7c4183f30f06a5a86cb6cd9d8231 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:12 -0600 Subject: [PATCH 2/7] cpumask: avoid deprecated function in mm/slab.c These days we use cpumask_empty() which takes a pointer. Signed-off-by: Rusty Russell Acked-by: Christoph Lameter --- mm/slab.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slab.c b/mm/slab.c index 3f4822938f4..7560eb00637 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1132,7 +1132,7 @@ static void __cpuinit cpuup_canceled(long cpu) if (nc) free_block(cachep, nc->entry, nc->avail, node); - if (!cpus_empty(*mask)) { + if (!cpumask_empty(mask)) { spin_unlock_irq(&l3->list_lock); goto free_array_cache; } From 6957177f5c3c0e51b9e90a1d7fadb3177a333949 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:14 -0600 Subject: [PATCH 3/7] cpumask: use modern cpumask style in drivers/scsi/fcoe/fcoe.c Signed-off-by: Rusty Russell Cc: "James E.J. Bottomley" Cc: Robert Love Cc: Chris Leech Cc: linux-scsi@vger.kernel.org --- drivers/scsi/fcoe/fcoe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index a30ffaa1222..51c24b37c60 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1231,7 +1231,7 @@ int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, "CPU.\n"); spin_unlock_bh(&fps->fcoe_rx_list.lock); - cpu = first_cpu(cpu_online_map); + cpu = cpumask_first(cpu_online_mask); fps = &per_cpu(fcoe_percpu, cpu); spin_lock_bh(&fps->fcoe_rx_list.lock); if (!fps->thread) { From cc216b86e51e9ab22265ea9591769c9ee235e1e4 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:24 -0600 Subject: [PATCH 4/7] cpumask: convert drivers/idle/i7300_idle.c to cpumask_var_t Fairly simple transformation: 1) cpumask_t -> cpumask_var_t and alloc_cpumask_var/free_cpumask_var (which are a NOOP unless CONFIG_CPUMASK_OFFSTACK=y). 2) cpu_set -> cpumask_set_cpu 3) cpus_weight -> cpumask_weight 4) cpu_clear -> cpumask_clear_cpu Signed-off-by: Rusty Russell To: Andy Henroid --- drivers/idle/i7300_idle.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c index 1f20a042a4f..dd253002cd5 100644 --- a/drivers/idle/i7300_idle.c +++ b/drivers/idle/i7300_idle.c @@ -81,7 +81,7 @@ static u8 i7300_idle_thrtctl_saved; static u8 i7300_idle_thrtlow_saved; static u32 i7300_idle_mc_saved; -static cpumask_t idle_cpumask; +static cpumask_var_t idle_cpumask; static ktime_t start_ktime; static unsigned long avg_idle_us; @@ -459,9 +459,9 @@ static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val, spin_lock_irqsave(&i7300_idle_lock, flags); if (val == IDLE_START) { - cpu_set(smp_processor_id(), idle_cpumask); + cpumask_set_cpu(smp_processor_id(), idle_cpumask); - if (cpus_weight(idle_cpumask) != num_online_cpus()) + if (cpumask_weight(idle_cpumask) != num_online_cpus()) goto end; now_ktime = ktime_get(); @@ -478,8 +478,8 @@ static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val, i7300_idle_ioat_start(); } else if (val == IDLE_END) { - cpu_clear(smp_processor_id(), idle_cpumask); - if (cpus_weight(idle_cpumask) == (num_online_cpus() - 1)) { + cpumask_clear_cpu(smp_processor_id(), idle_cpumask); + if (cpumask_weight(idle_cpumask) == (num_online_cpus() - 1)) { /* First CPU coming out of idle */ u64 idle_duration_us; @@ -553,7 +553,6 @@ struct debugfs_file_info { static int __init i7300_idle_init(void) { spin_lock_init(&i7300_idle_lock); - cpus_clear(idle_cpumask); total_us = 0; if (i7300_idle_platform_probe(&fbd_dev, &ioat_dev, forceload)) @@ -565,6 +564,9 @@ static int __init i7300_idle_init(void) if (i7300_idle_ioat_init()) return -ENODEV; + if (!zalloc_cpumask_var(&idle_cpumask, GFP_KERNEL)) + return -ENOMEM; + debugfs_dir = debugfs_create_dir("i7300_idle", NULL); if (debugfs_dir) { int i = 0; @@ -589,6 +591,7 @@ static int __init i7300_idle_init(void) static void __exit i7300_idle_exit(void) { idle_notifier_unregister(&i7300_idle_nb); + free_cpumask_var(idle_cpumask); if (debugfs_dir) { int i = 0; From 62ac12795095dc959649c66ace78708e7ac52477 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:26 -0600 Subject: [PATCH 5/7] cpumask: avoid dereferencing struct cpumask struct cpumask will be undefined soon with CONFIG_CPUMASK_OFFSTACK=y, to avoid them being declared on the stack. cpumask_bits() does what we want here (of course, this code is crap). Signed-off-by: Rusty Russell To: Thomas Gleixner --- kernel/time/timer_list.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 28265636b6c..bdfb8dd1050 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -237,10 +237,10 @@ static void timer_list_show_tickdevices(struct seq_file *m) #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST print_tickdevice(m, tick_get_broadcast_device(), -1); SEQ_printf(m, "tick_broadcast_mask: %08lx\n", - tick_get_broadcast_mask()->bits[0]); + cpumask_bits(tick_get_broadcast_mask())[0]); #ifdef CONFIG_TICK_ONESHOT SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n", - tick_get_broadcast_oneshot_mask()->bits[0]); + cpumask_bits(tick_get_broadcast_oneshot_mask())[0]); #endif SEQ_printf(m, "\n"); #endif From 4251417484a1775ba5cbfe38c67e6d5af9615de4 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:29 -0600 Subject: [PATCH 6/7] cpumask: don't recommend set_cpus_allowed hack in Documentation/cpu-hotplug.txt Signed-off-by: Rusty Russell Cc: Gautham R Shenoy Cc: Ashok Raj --- Documentation/cpu-hotplug.txt | 49 ++++++++++++----------------------- 1 file changed, 17 insertions(+), 32 deletions(-) diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt index 4d4a644b505..a99d7031cdf 100644 --- a/Documentation/cpu-hotplug.txt +++ b/Documentation/cpu-hotplug.txt @@ -315,41 +315,26 @@ A: The following are what is required for CPU hotplug infrastructure to work Q: I need to ensure that a particular cpu is not removed when there is some work specific to this cpu is in progress. -A: First switch the current thread context to preferred cpu +A: There are two ways. If your code can be run in interrupt context, use + smp_call_function_single(), otherwise use work_on_cpu(). Note that + work_on_cpu() is slow, and can fail due to out of memory: int my_func_on_cpu(int cpu) { - cpumask_t saved_mask, new_mask = CPU_MASK_NONE; - int curr_cpu, err = 0; - - saved_mask = current->cpus_allowed; - cpu_set(cpu, new_mask); - err = set_cpus_allowed(current, new_mask); - - if (err) - return err; - - /* - * If we got scheduled out just after the return from - * set_cpus_allowed() before running the work, this ensures - * we stay locked. - */ - curr_cpu = get_cpu(); - - if (curr_cpu != cpu) { - err = -EAGAIN; - goto ret; - } else { - /* - * Do work : But cant sleep, since get_cpu() disables preempt - */ - } - ret: - put_cpu(); - set_cpus_allowed(current, saved_mask); - return err; - } - + int err; + get_online_cpus(); + if (!cpu_online(cpu)) + err = -EINVAL; + else +#if NEEDS_BLOCKING + err = work_on_cpu(cpu, __my_func_on_cpu, NULL); +#else + smp_call_function_single(cpu, __my_func_on_cpu, &err, + true); +#endif + put_online_cpus(); + return err; + } Q: How do we determine how many CPUs are available for hotplug. A: There is no clear spec defined way from ACPI that can give us that From a4636818f8e0991f32d9528f39cf4f3d6a7d30a3 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:29 -0600 Subject: [PATCH 7/7] cpumask: rename tsk_cpumask to tsk_cpus_allowed Noone uses this wrapper yet, and Ingo asked that it be kept consistent with current task_struct usage. (One user crept in via linux-next: fixed) Signed-off-by: Rusty Russell Cc: Tejun Heo --- arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 2 +- include/linux/sched.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c index a9df9441a9a..f125e5c551c 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c @@ -1136,7 +1136,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, if (!alloc_cpumask_var(&oldmask, GFP_KERNEL)) return -ENOMEM; - cpumask_copy(oldmask, tsk_cpumask(current)); + cpumask_copy(oldmask, tsk_cpus_allowed(current)); set_cpus_allowed_ptr(current, cpumask_of(pol->cpu)); if (smp_processor_id() != pol->cpu) { diff --git a/include/linux/sched.h b/include/linux/sched.h index 244c287a5ac..4d7adb282bd 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1555,7 +1555,7 @@ struct task_struct { }; /* Future-safe accessor for struct task_struct's cpus_allowed. */ -#define tsk_cpumask(tsk) (&(tsk)->cpus_allowed) +#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed) /* * Priority of a process goes from 0..MAX_PRIO-1, valid RT