Use unsigned long for dealing with jiffies not int. Rename the
callback to something sensible. Use __this_cpu_read/write for
accessing per cpu data.
Signed-off-by: Thomas Gleixner <[email protected]>
---
arch/x86/kernel/cpu/mcheck/mce.c | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)
Index: linux-2.6/arch/x86/kernel/cpu/mcheck/mce.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/mcheck/mce.c
+++ linux-2.6/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1237,15 +1237,15 @@ void mce_log_therm_throt_event(__u64 sta
* poller finds an MCE, poll 2x faster. When the poller finds no more
* errors, poll 2x slower (up to check_interval seconds).
*/
-static int check_interval = 5 * 60; /* 5 minutes */
+static unsigned long check_interval = 5 * 60; /* 5 minutes */
-static DEFINE_PER_CPU(int, mce_next_interval); /* in jiffies */
+static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */
static DEFINE_PER_CPU(struct timer_list, mce_timer);
-static void mce_start_timer(unsigned long data)
+static void mce_timer_fn(unsigned long data)
{
- struct timer_list *t = &per_cpu(mce_timer, data);
- int *n;
+ struct timer_list *t = &__get_cpu_var(mce_timer);
+ unsigned long iv;
WARN_ON(smp_processor_id() != data);
@@ -1258,13 +1258,14 @@ static void mce_start_timer(unsigned lon
* Alert userspace if needed. If we logged an MCE, reduce the
* polling interval, otherwise increase the polling interval.
*/
- n = &__get_cpu_var(mce_next_interval);
+ iv = __this_cpu_read(mce_next_interval);
if (mce_notify_irq())
- *n = max(*n/2, HZ/100);
+ iv = max(iv, (unsigned long) HZ/100);
else
- *n = min(*n*2, (int)round_jiffies_relative(check_interval*HZ));
+ iv = min(iv * 2, round_jiffies_relative(check_interval * HZ));
+ __this_cpu_write(mce_next_interval, iv);
- t->expires = jiffies + *n;
+ t->expires = jiffies + iv;
add_timer_on(t, smp_processor_id());
}
@@ -1542,17 +1543,17 @@ static void __mcheck_cpu_init_vendor(str
static void __mcheck_cpu_init_timer(void)
{
struct timer_list *t = &__get_cpu_var(mce_timer);
- int *n = &__get_cpu_var(mce_next_interval);
+ unsigned long iv = __this_cpu_read(mce_next_interval);
- setup_timer(t, mce_start_timer, smp_processor_id());
+ setup_timer(t, mce_timer_fn, smp_processor_id());
if (mce_ignore_ce)
return;
- *n = check_interval * HZ;
- if (!*n)
+ __this_cpu_write(mce_next_interval, iv);
+ if (!iv)
return;
- t->expires = round_jiffies(jiffies + *n);
+ t->expires = round_jiffies(jiffies + iv);
add_timer_on(t, smp_processor_id());
}
@@ -2262,7 +2263,7 @@ mce_cpu_callback(struct notifier_block *
case CPU_DOWN_FAILED_FROZEN:
if (!mce_ignore_ce && check_interval) {
t->expires = round_jiffies(jiffies +
- __get_cpu_var(mce_next_interval));
+ per_cpu(mce_next_interval, cpu));
add_timer_on(t, cpu);
}
smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
On Thu, May 24, 2012 at 05:54:51PM +0000, Thomas Gleixner wrote:
> Use unsigned long for dealing with jiffies not int. Rename the
> callback to something sensible. Use __this_cpu_read/write for
> accessing per cpu data.
>
> Signed-off-by: Thomas Gleixner <[email protected]>
Looks good to me,
thanks.
Acked-by: Borislav Petkov <[email protected]>
--
Regards/Gruss,
Boris.
Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551
Hi, Tony and Thomas
This patch has been merged, but It still have some confusion, please
see inline comment and give me some explanation.
于 2012/5/25 1:54, Thomas Gleixner 写道:
> Use unsigned long for dealing with jiffies not int. Rename the
> callback to something sensible. Use __this_cpu_read/write for
> accessing per cpu data.
>
> Signed-off-by: Thomas Gleixner <[email protected]> ---
> arch/x86/kernel/cpu/mcheck/mce.c | 31
> ++++++++++++++++--------------- 1 file changed, 16 insertions(+),
> 15 deletions(-)
>
> Index: linux-2.6/arch/x86/kernel/cpu/mcheck/mce.c
> ===================================================================
>
>
>
--- linux-2.6.orig/arch/x86/kernel/cpu/mcheck/mce.c
> +++ linux-2.6/arch/x86/kernel/cpu/mcheck/mce.c @@ -1237,15
> +1237,15 @@ void mce_log_therm_throt_event(__u64 sta * poller finds
> an MCE, poll 2x faster. When the poller finds no more * errors,
> poll 2x slower (up to check_interval seconds). */ -static int
> check_interval = 5 * 60; /* 5 minutes */ +static unsigned long
> check_interval = 5 * 60; /* 5 minutes */
>
> -static DEFINE_PER_CPU(int, mce_next_interval); /* in jiffies */
> +static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in
> jiffies */ static DEFINE_PER_CPU(struct timer_list, mce_timer);
>
> -static void mce_start_timer(unsigned long data) +static void
> mce_timer_fn(unsigned long data) { - struct timer_list *t =
> &per_cpu(mce_timer, data); - int *n; + struct timer_list *t =
> &__get_cpu_var(mce_timer); + unsigned long iv;
>
> WARN_ON(smp_processor_id() != data);
>
> @@ -1258,13 +1258,14 @@ static void mce_start_timer(unsigned lon *
> Alert userspace if needed. If we logged an MCE, reduce the *
> polling interval, otherwise increase the polling interval. */ - n
> = &__get_cpu_var(mce_next_interval); + iv =
> __this_cpu_read(mce_next_interval); if (mce_notify_irq()) - *n =
> max(*n/2, HZ/100); + iv = max(iv, (unsigned long) HZ/100);
Here Thomas changed original mode from "*n = max(*n/2, HZ/100);"
to "iv = max(iv, (unsigned long) HZ/100);", which means *iv* will not
be decremented but only incremented in _else_ branch. If so, eventually
the *iv will be equal to *check_interval*. I don't think it makes sense.
Even we use new logic, the comment before these codes should be updated.
So Thomas, would you please explain why you use this new logic?
> else - *n = min(*n*2,
> (int)round_jiffies_relative(check_interval*HZ)); + iv = min(iv *
> 2, round_jiffies_relative(check_interval * HZ)); +
> __this_cpu_write(mce_next_interval, iv);
>
> - t->expires = jiffies + *n; + t->expires = jiffies + iv;
> add_timer_on(t, smp_processor_id()); }
>
> @@ -1542,17 +1543,17 @@ static void __mcheck_cpu_init_vendor(str
> static void __mcheck_cpu_init_timer(void) { struct timer_list *t =
> &__get_cpu_var(mce_timer); - int *n =
> &__get_cpu_var(mce_next_interval); + unsigned long iv =
> __this_cpu_read(mce_next_interval);
>
> - setup_timer(t, mce_start_timer, smp_processor_id()); +
> setup_timer(t, mce_timer_fn, smp_processor_id());
>
> if (mce_ignore_ce) return;
>
> - *n = check_interval * HZ; - if (!*n) +
> __this_cpu_write(mce_next_interval, iv); + if (!iv) return; -
> t->expires = round_jiffies(jiffies + *n); + t->expires =
> round_jiffies(jiffies + iv); add_timer_on(t, smp_processor_id());
> }
>
> @@ -2262,7 +2263,7 @@ mce_cpu_callback(struct notifier_block *
> case CPU_DOWN_FAILED_FROZEN: if (!mce_ignore_ce && check_interval)
> { t->expires = round_jiffies(jiffies + -
> __get_cpu_var(mce_next_interval)); +
> per_cpu(mce_next_interval, cpu)); add_timer_on(t, cpu); }
> smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
>
>
>
> Here Thomas changed original mode from "*n = max(*n/2, HZ/100);"
> to "iv = max(iv, (unsigned long) HZ/100);", which means *iv* will not
> be decremented but only incremented in _else_ branch. If so, eventually
> the *iv will be equal to *check_interval*. I don't think it makes sense.
It looks like Thomas just forgot the "/ 2" there while cleaning up.
I didn't see it either, nor did Boris when he acked it. Thank goodness
for your extra eyes looking at this.
Please send patch to fix it (so you get credit).
-Tony
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On Mon, 4 Jun 2012, Luck, Tony wrote:
> > Here Thomas changed original mode from "*n = max(*n/2, HZ/100);"
> > to "iv = max(iv, (unsigned long) HZ/100);", which means *iv* will not
> > be decremented but only incremented in _else_ branch. If so, eventually
> > the *iv will be equal to *check_interval*. I don't think it makes sense.
>
> It looks like Thomas just forgot the "/ 2" there while cleaning up.
> I didn't see it either, nor did Boris when he acked it. Thank goodness
> for your extra eyes looking at this.
Uurgh. Chen, thanks for spotting it!
On Mon, Jun 04, 2012 at 06:14:38PM +0000, Luck, Tony wrote:
> > Here Thomas changed original mode from "*n = max(*n/2, HZ/100);"
> > to "iv = max(iv, (unsigned long) HZ/100);", which means *iv* will not
> > be decremented but only incremented in _else_ branch. If so, eventually
> > the *iv will be equal to *check_interval*. I don't think it makes sense.
>
> It looks like Thomas just forgot the "/ 2" there while cleaning up.
> I didn't see it either, nor did Boris when he acked it. Thank goodness
> for your extra eyes looking at this.
We should all pack our bags and go home. :<|
--
Regards/Gruss,
Boris.
Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551