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authorRusty Russell <rusty@rustcorp.com.au>2008-07-28 12:16:30 -0500
committerRusty Russell <rusty@rustcorp.com.au>2008-07-28 12:16:30 +1000
commiteeec4fad963490821348a331cca6102ae1c4a7a3 (patch)
tree163a7d9414d719fccac096d1ba822416f705b397 /kernel
parent04321587584272f4e8b9818f319f40caf8eeee13 (diff)
downloadop-kernel-dev-eeec4fad963490821348a331cca6102ae1c4a7a3.zip
op-kernel-dev-eeec4fad963490821348a331cca6102ae1c4a7a3.tar.gz
stop_machine(): stop_machine_run() changed to use cpu mask
Instead of a "cpu" arg with magic values NR_CPUS (any cpu) and ~0 (all cpus), pass a cpumask_t. Allow NULL for the common case (where we don't care which CPU the function is run on): temporary cpumask_t's are usually considered bad for stack space. This deprecates stop_machine_run, to be removed soon when all the callers are dead. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c3
-rw-r--r--kernel/stop_machine.c27
2 files changed, 15 insertions, 15 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 53cf508..29510d68 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -248,8 +248,9 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
cpus_setall(tmp);
cpu_clear(cpu, tmp);
set_cpus_allowed_ptr(current, &tmp);
+ tmp = cpumask_of_cpu(cpu);
- err = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
+ err = __stop_machine(take_cpu_down, &tcd_param, &tmp);
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 35882dc..e446c7c 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -100,7 +100,7 @@ static int chill(void *unused)
return 0;
}
-int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
+int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
{
int i, err;
struct stop_machine_data active, idle;
@@ -112,10 +112,6 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
idle.fn = chill;
idle.data = NULL;
- /* If they don't care which cpu fn runs on, just pick one. */
- if (cpu == NR_CPUS)
- cpu = any_online_cpu(cpu_online_map);
-
/* This could be too big for stack on large machines. */
threads = kcalloc(NR_CPUS, sizeof(threads[0]), GFP_KERNEL);
if (!threads)
@@ -128,13 +124,16 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
set_state(STOPMACHINE_PREPARE);
for_each_online_cpu(i) {
- struct stop_machine_data *smdata;
+ struct stop_machine_data *smdata = &idle;
struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
- if (cpu == ALL_CPUS || i == cpu)
- smdata = &active;
- else
- smdata = &idle;
+ if (!cpus) {
+ if (i == first_cpu(cpu_online_map))
+ smdata = &active;
+ } else {
+ if (cpu_isset(i, *cpus))
+ smdata = &active;
+ }
threads[i] = kthread_create((void *)stop_cpu, smdata, "kstop%u",
i);
@@ -154,7 +153,7 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
/* We've created all the threads. Wake them all: hold this CPU so one
* doesn't hit this CPU until we're ready. */
- cpu = get_cpu();
+ get_cpu();
for_each_online_cpu(i)
wake_up_process(threads[i]);
@@ -177,15 +176,15 @@ kill_threads:
return err;
}
-int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
+int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
{
int ret;
/* No CPUs can come up or down during this. */
get_online_cpus();
- ret = __stop_machine_run(fn, data, cpu);
+ ret = __stop_machine(fn, data, cpus);
put_online_cpus();
return ret;
}
-EXPORT_SYMBOL_GPL(stop_machine_run);
+EXPORT_SYMBOL_GPL(stop_machine);
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