Subject: Re: linux-next: build warning after merge of the tip tree

From: "Liang, Kan" <[email-masked]>
Date: Thu, 12 Sep 2024 10:52:16 -0400

On 2024-09-11 1:38 a.m., Stephen Rothwell wrote:
> Hi all,
> 
> After merging the tip tree, today's linux-next build (arm
> multi_v7_defconfig) produced this warning:
> 
> kernel/events/core.c: In function 'perf_event_setup_cpumask':
> kernel/events/core.c:14012:13: warning: the comparison will always evaluate as 'true' for the address of 'thread_sibling' will never be NULL [-Waddress]
> 14012 |         if (!topology_sibling_cpumask(cpu)) {
>       |             ^
> In file included from include/linux/topology.h:30,
>                  from include/linux/gfp.h:8,
>                  from include/linux/xarray.h:16,
>                  from include/linux/list_lru.h:14,
>                  from include/linux/fs.h:13,
>                  from kernel/events/core.c:11:
> include/linux/arch_topology.h:78:19: note: 'thread_sibling' declared here
>    78 |         cpumask_t thread_sibling;
>       |                   ^~~~~~~~~~~~~~
> 
> Introduced by commit
> 
>   4ba4f1afb6a9 ("perf: Generic hotplug support for a PMU with a scope")
> 

The patch to fix the warning has been posted.
https://lore.kernel.org/lkml/[email-masked]/

Please give it a try.

Thanks,
Kan