Re: [PATCH] mm/page_isolation: fix clang deadcode warning

[Aiqun(Maria) Yu]

On 10/21/2022 11:19 AM, Matthew Wilcox wrote:
> On Fri, Oct 21, 2022 at 11:09:53AM +0800, Maria Yu wrote:
> > When !CONFIG_VM_BUG_ON, there is warning of
> > clang-analyzer-deadcode.DeadStores:
> > Value stored to 'mt' during its initialization
> > is never read.
>
> Honestly, the cure is worse than the disease.  I'd rather not have a
> line that's this long.
I don't like this long either. While the current Deadcode warning is 
also annoying for our clang tidy check.

will the CONFIG check can be acceptable?
like:
	#ifdef CONFIG_DEBUG_VM
or
	if (IS_ENABLED(CONFIG_DEBUG_VM))

Any good ideas?

> >> -		int mt = get_pageblock_migratetype(pfn_to_page(isolate_pageblock));
> > -
> > -		VM_BUG_ON(!is_migrate_isolate(mt));
> > +		VM_BUG_ON(!is_migrate_isolate(get_pageblock_migratetype(pfn_to_page(isolate_pageblock))));


--
Thx and BRs,
Aiqun(Maria) Yu