[v2] kthread: Fix build warning variable 'ret' set but not used

[PATCH V2] kthread: Fix build warning variable 'ret' set but not used

Posted by Dhruva Gole 10 months, 1 week ago

Fix the following build time warning in kthread:

   kernel/kthread.c: In function 'kthread_affine_preferred':
>> kernel/kthread.c:861:13: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
     861 |         int ret;
         |             ^~~

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501301528.t0cZVbnq-lkp@intel.com/
Signed-off-by: Dhruva Gole <d-gole@ti.com>
---
Link to v1:
https://lore.kernel.org/lkml/20250204090838.214647-1-d-gole@ti.com/

Changelog:
- Use ret value toward the end return as per Kees' suggestion

---

 kernel/kthread.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index 4005b13ebd7f..5dc5b0d7238e 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -859,7 +859,7 @@ int kthread_affine_preferred(struct task_struct *p, const struct cpumask *mask)
 	struct kthread *kthread = to_kthread(p);
 	cpumask_var_t affinity;
 	unsigned long flags;
-	int ret;
+	int ret = 0;
 
 	if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE) || kthread->started) {
 		WARN_ON(1);
@@ -892,7 +892,7 @@ int kthread_affine_preferred(struct task_struct *p, const struct cpumask *mask)
 out:
 	free_cpumask_var(affinity);
 
-	return 0;
+	return ret;
 }
 
 /*

base-commit: 40b8e93e17bff4a4e0cc129e04f9fdf5daa5397e
-- 
2.34.1

Re: [PATCH V2] kthread: Fix build warning variable 'ret' set but not used

Posted by Frederic Weisbecker 10 months, 1 week ago

Hi Dhruva,

Le Tue, Feb 04, 2025 at 09:39:21PM +0530, Dhruva Gole a écrit :
> Fix the following build time warning in kthread:
> 
>    kernel/kthread.c: In function 'kthread_affine_preferred':
> >> kernel/kthread.c:861:13: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
>      861 |         int ret;
>          |             ^~~
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202501301528.t0cZVbnq-lkp@intel.com/
> Signed-off-by: Dhruva Gole <d-gole@ti.com>

Thanks for your patch but another similar fix was already pending. I have sent
the pull request there:

https://lore.kernel.org/lkml/Z6JjZMdbDoAX_AVW@pavilion.home/T/#u

Re: [PATCH V2] kthread: Fix build warning variable 'ret' set but not used

Posted by Dhruva Gole 10 months, 1 week ago

On Feb 04, 2025 at 20:02:19 +0100, Frederic Weisbecker wrote:
> Hi Dhruva,
> 
> Le Tue, Feb 04, 2025 at 09:39:21PM +0530, Dhruva Gole a écrit :
> > Fix the following build time warning in kthread:
> > 
> >    kernel/kthread.c: In function 'kthread_affine_preferred':
> > >> kernel/kthread.c:861:13: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
> >      861 |         int ret;
> >          |             ^~~
> > 
> > Reported-by: kernel test robot <lkp@intel.com>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202501301528.t0cZVbnq-lkp@intel.com/
> > Signed-off-by: Dhruva Gole <d-gole@ti.com>
> 
> Thanks for your patch but another similar fix was already pending. I have sent
> the pull request there:
> 
> https://lore.kernel.org/lkml/Z6JjZMdbDoAX_AVW@pavilion.home/T/#u

OK, btw another qn I had was does this file not need a MAINTAINERS file
update?
I don't see a real MAINTAINER against it, everyone just shows as
contributors / committers...
Or is it to be sent to Linus directly?

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

Re: [PATCH V2] kthread: Fix build warning variable 'ret' set but not used

Posted by Frederic Weisbecker 10 months, 1 week ago

Le Wed, Feb 05, 2025 at 11:47:40AM +0530, Dhruva Gole a écrit :
> On Feb 04, 2025 at 20:02:19 +0100, Frederic Weisbecker wrote:
> > Hi Dhruva,
> > 
> > Le Tue, Feb 04, 2025 at 09:39:21PM +0530, Dhruva Gole a écrit :
> > > Fix the following build time warning in kthread:
> > > 
> > >    kernel/kthread.c: In function 'kthread_affine_preferred':
> > > >> kernel/kthread.c:861:13: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
> > >      861 |         int ret;
> > >          |             ^~~
> > > 
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202501301528.t0cZVbnq-lkp@intel.com/
> > > Signed-off-by: Dhruva Gole <d-gole@ti.com>
> > 
> > Thanks for your patch but another similar fix was already pending. I have sent
> > the pull request there:
> > 
> > https://lore.kernel.org/lkml/Z6JjZMdbDoAX_AVW@pavilion.home/T/#u
> 
> OK, btw another qn I had was does this file not need a MAINTAINERS file
> update?
> I don't see a real MAINTAINER against it, everyone just shows as
> contributors / committers...
> Or is it to be sent to Linus directly?

There is no official maintainer for kthreads. But I volunteer to handle the patches
targeted to it at least for a while given my recent invasive changes there.

Thanks.

> 
> -- 
> Best regards,
> Dhruva Gole
> Texas Instruments Incorporated