The patch titled
cpu-hotplug: return better errno on cpu hotplug failure
has been added to the -mm tree. Its filename is
cpu-hotplug-return-better-errno-on-cpu-hotplug-failure.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: cpu-hotplug: return better errno on cpu hotplug failure
From: Akinobu Mita <akinobu.mita@xxxxxxxxx>
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@xxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/cpu.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff -puN kernel/cpu.c~cpu-hotplug-return-better-errno-on-cpu-hotplug-failure kernel/cpu.c
--- a/kernel/cpu.c~cpu-hotplug-return-better-errno-on-cpu-hotplug-failure
+++ a/kernel/cpu.c
@@ -136,8 +136,12 @@ int __ref register_cpu_notifier(struct n
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)
@@ -150,7 +154,7 @@ static void cpu_notify_nofail(unsigned l
int err;
err = cpu_notify(val, v);
- BUG_ON(err == NOTIFY_BAD);
+ BUG_ON(err);
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -230,14 +234,13 @@ static int __ref _cpu_down(unsigned int
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;
}
@@ -314,11 +317,10 @@ static int __cpuinit _cpu_up(unsigned in
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;
}
_
Patches currently in -mm which might be from akinobu.mita@xxxxxxxxx are
intel-iommu-use-for_each_set_bit.patch
bitops-rename-for_each_bit-to-for_each_set_bit-mtd.patch
cpu-hotplug-introduce-cpu_notify-__cpu_notify-cpu_notify_nofail.patch
cpu-hotplug-return-better-errno-on-cpu-hotplug-failure.patch
notifier-change-notifier_from_errno0-to-return-notify_ok.patch
x86-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
topology-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
kernel-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
slab-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
iucv-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
ehca-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
s390-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
md-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
fault-injection-add-cpu-notifier-error-injection-module.patch
bitops-remove-temporary-for_each_bit.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
