linux-kernel - Re: [PATCH 2/3] mm/hugetlb: Remove unnecessary if condition

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Message-ID: <20260115211053.1406264-1-joshua.hahnjy@gmail.com>
Date: Thu, 15 Jan 2026 16:10:51 -0500
From: Joshua Hahn <joshua.hahnjy@...il.com>
To: "David Hildenbrand (Red Hat)" <david@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	Muchun Song <muchun.song@...ux.dev>,
	Oscar Salvador <osalvador@...e.de>,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
Subject: Re: [PATCH 2/3] mm/hugetlb: Remove unnecessary if condition

On Thu, 15 Jan 2026 21:14:15 +0100 "David Hildenbrand (Red Hat)" <david@...nel.org> wrote:

> On 1/15/26 19:14, Joshua Hahn wrote:
> > if (map_chg) is always true, since it is nested in another if statement
> > which checks for it already. Remove the check and un-indent for readability.
> > 
> > if (unlikely(map_chg == MAP_CHG_NEEDED && retval == 0)) {
> > 	...
> > 
> > 	if (map_chg) {
> > 		...
> > 	}
> > }
> > 
> > No functional change intended.
> > 
> > Signed-off-by: Joshua Hahn <joshua.hahnjy@...il.com>
> > ---
> >   mm/hugetlb.c | 12 +++++-------
> >   1 file changed, 5 insertions(+), 7 deletions(-)
> > 
> > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> > index 88b9e997c9da..432a5054ca1d 100644
> > --- a/mm/hugetlb.c
> > +++ b/mm/hugetlb.c
> > @@ -3019,13 +3019,11 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
> >   
> >   			rsv_adjust = hugepage_subpool_put_pages(spool, 1);
> >   			hugetlb_acct_memory(h, -rsv_adjust);
> > -			if (map_chg) {
> > -				spin_lock_irq(&hugetlb_lock);
> > -				hugetlb_cgroup_uncharge_folio_rsvd(
> > -				    hstate_index(h), pages_per_huge_page(h),
> > -				    folio);
> > -				spin_unlock_irq(&hugetlb_lock);
> > -			}
> > +			spin_lock_irq(&hugetlb_lock);
> > +			hugetlb_cgroup_uncharge_folio_rsvd(
> > +			    hstate_index(h), pages_per_huge_page(h),
> > +			    folio);
> > +			spin_unlock_irq(&hugetlb_lock);
> >   		}
> >   	}
> >   
> 
> MAP_CHG_NEEDED = 1
> 
> Acked-by: David Hildenbrand (Red Hat) <david@...nel.org>

Thank you David, I agree it's helpful to include MAP_CHG_NEEDED != 0.
Will add in the v2! Have a great day : -)

Joshua