diff options
| author | Akinobu Mita <akinobu.mita@gmail.com> | 2010-05-26 14:43:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-27 09:12:47 -0700 |
| commit | e6bde73b07edeb703d4c89c1daabc09c303de11f (patch) | |
| tree | 9b60a3fc2ce002b26e46611357cb5529795e7ac5 /kernel | |
| parent | e9fb7631ebcdc9467cbb736337546a42f7b7f28e (diff) | |
cpu-hotplug: return better errno on cpu hotplug failure
Currently, onlining or offlining a CPU failure by one of the cpu notifiers
error always cause -EINVAL error. (i.e. writing 0 or 1 to
/sys/devices/system/cpu/cpuX/online gets EINVAL)
To get better error reporting rather than always getting -EINVAL, This
changes cpu_notify() to return -errno value with notifier_to_errno() and
fix the callers. Now that cpu notifiers can return encapsulate errno
value.
Currently, all cpu hotplug notifiers return NOTIFY_OK, NOTIFY_BAD, or
NOTIFY_DONE. So cpu_notify() can returns 0 or -EPERM with this change for
now.
(notifier_to_errno(NOTIFY_OK) == 0, notifier_to_errno(NOTIFY_DONE) == 0,
notifier_to_errno(NOTIFY_BAD) == -EPERM)
Forthcoming patches convert several cpu notifiers to return encapsulate
errno value with notifier_from_errno().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpu.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 09207c772c25..0690ac27a253 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -137,8 +137,12 @@ int __ref register_cpu_notifier(struct notifier_block *nb) static int __cpu_notify(unsigned long val, void *v, int nr_to_call, int *nr_calls) { - return __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, + int ret; + + ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, nr_calls); + + return notifier_to_errno(ret); } static int cpu_notify(unsigned long val, void *v) @@ -151,7 +155,7 @@ static void cpu_notify_nofail(unsigned long val, void *v) int err; err = cpu_notify(val, v); - BUG_ON(err == NOTIFY_BAD); + BUG_ON(err); } #ifdef CONFIG_HOTPLUG_CPU @@ -232,14 +236,13 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) cpu_hotplug_begin(); set_cpu_active(cpu, false); err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); - if (err == NOTIFY_BAD) { + if (err) { set_cpu_active(cpu, true); nr_calls--; __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); printk("%s: attempt to take down CPU %u failed\n", __func__, cpu); - err = -EINVAL; goto out_release; } @@ -304,11 +307,10 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) cpu_hotplug_begin(); ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); - if (ret == NOTIFY_BAD) { + if (ret) { nr_calls--; printk("%s: attempt to bring up CPU %u failed\n", __func__, cpu); - ret = -EINVAL; goto out_notify; } |