Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 11 Dec 2018 13:12:54 -0800 (PST) | From | David Rientjes <> | Subject | Re: [PATCH] mm/mmu_notifier: fix mmu_notifier_range_init warning |
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On Tue, 11 Dec 2018, Jerome Glisse wrote:
> On Tue, Dec 11, 2018 at 09:04:43PM +0100, Arnd Bergmann wrote: > > The macro version of mmu_notifier_range_init() for CONFIG_MMU_NOTIFIER=n > > does not evaluate all its arguments, leading to a warning in one case: > > > > mm/migrate.c: In function 'migrate_vma_pages': > > mm/migrate.c:2711:20: error: unused variable 'mm' [-Werror=unused-variable] > > struct mm_struct *mm = vma->vm_mm; > > > > Pass down the 'mm' as into the inline function as well so gcc can > > see why the variable exists. > > > > Fixes: 137d92bd73b1 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2") > > What about changing migrate.c (i actualy tried to do that everywhere in > the patchset but i missed that spot) So we avoid one useless variable on > such configuration: > > diff --git a/mm/migrate.c b/mm/migrate.c > index f02bb4b22c1a..883fce631f47 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2701,7 +2701,6 @@ static void migrate_vma_pages(struct migrate_vma *migrate) > const unsigned long npages = migrate->npages; > const unsigned long start = migrate->start; > struct vm_area_struct *vma = migrate->vma; > - struct mm_struct *mm = vma->vm_mm; > struct mmu_notifier_range range; > unsigned long addr, i; > bool notified = false; > @@ -2724,8 +2723,8 @@ static void migrate_vma_pages(struct migrate_vma *migrate) > if (!notified) { > notified = true; > > - mmu_notifier_range_init(&range, mm, addr, > - migrate->end, > + mmu_notifier_range_init(&range, vma->vm_mm, > + addr, migrate->end, > MMU_NOTIFY_CLEAR); > mmu_notifier_invalidate_range_start(&range); > }
Wouldn't it be better to just declare mmu_notifier_range_init() as a static inline function rather than a #define to avoid this warning?
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