2020-08-14 14:15:30

by Balamuruhan S

Subject: [PATCH] kernel/watchdog: fix warning -Wunused-variable for watchdog_allowed_mask in ppc64

In ppc64 config if `CONFIG_SOFTLOCKUP_DETECTOR` is not set then it
warns for unused declaration of `watchdog_allowed_mask` while building,
move the declaration inside ifdef later in the code.

```
kernel/watchdog.c:47:23: warning: ‘watchdog_allowed_mask’ defined but not used [-Wunused-variable]
static struct cpumask watchdog_allowed_mask __read_mostly;
```

Signed-off-by: Balamuruhan S <[email protected]>
---
kernel/watchdog.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 5abb5b22ad13..33c9b8a3d51b 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -44,7 +44,6 @@ int __read_mostly soft_watchdog_user_enabled = 1;
int __read_mostly watchdog_thresh = 10;
static int __read_mostly nmi_watchdog_available;

-static struct cpumask watchdog_allowed_mask __read_mostly;

struct cpumask watchdog_cpumask __read_mostly;
unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
@@ -166,6 +165,7 @@ int __read_mostly sysctl_softlockup_all_cpu_backtrace;
unsigned int __read_mostly softlockup_panic =
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;

+static struct cpumask watchdog_allowed_mask __read_mostly;
static bool softlockup_initialized __read_mostly;
static u64 __read_mostly sample_period;


base-commit: a3a28c4451dff698d0c7ef5a3e80423aa5774e2b
--
2.24.1

2020-08-20 11:42:40

by Petr Mladek

Subject: Re: [PATCH] kernel/watchdog: fix warning -Wunused-variable for watchdog_allowed_mask in ppc64

On Fri 2020-08-14 19:03:30, Balamuruhan S wrote:
> In ppc64 config if `CONFIG_SOFTLOCKUP_DETECTOR` is not set then it
> warns for unused declaration of `watchdog_allowed_mask` while building,
> move the declaration inside ifdef later in the code.
>
> ```
> kernel/watchdog.c:47:23: warning: ‘watchdog_allowed_mask’ defined but not used [-Wunused-variable]
> static struct cpumask watchdog_allowed_mask __read_mostly;
> ```
>
> Signed-off-by: Balamuruhan S <[email protected]>
> ---
> kernel/watchdog.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/watchdog.c b/kernel/watchdog.c
> index 5abb5b22ad13..33c9b8a3d51b 100644
> --- a/kernel/watchdog.c
> +++ b/kernel/watchdog.c
> @@ -44,7 +44,6 @@ int __read_mostly soft_watchdog_user_enabled = 1;
> int __read_mostly watchdog_thresh = 10;
> static int __read_mostly nmi_watchdog_available;
>
> -static struct cpumask watchdog_allowed_mask __read_mostly;
>
> struct cpumask watchdog_cpumask __read_mostly;
> unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
> @@ -166,6 +165,7 @@ int __read_mostly sysctl_softlockup_all_cpu_backtrace;
> unsigned int __read_mostly softlockup_panic =
> CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
>
> +static struct cpumask watchdog_allowed_mask __read_mostly;

I could confirm that the variable is used only in code that is built
when CONFIG_SOFTLOCKUP_DETECTOR is enabled.

Note that the problem can't be seen on x86. There the softlockup
detector is enforced together with hardloclup detector via
via HARDLOCKUP_DETECTOR_PERF.

Reviewed-by: Petr Mladek <[email protected]>

Best Regards,
Petr