Re: [PATCH][v2] mm/hugetlb: early exit from hugetlb_pages_alloc_boot() when max_huge_pages=0

[Andrew Morton]

On Sun, 17 Aug 2025 19:21:54 -0700 jane.chu@xxxxxxxxxx wrote:

> 
> On 8/14/2025 3:23 AM, lirongqing wrote:
> > From: Li RongQing <lirongqing@xxxxxxxxx>
> > 
> > Optimize hugetlb_pages_alloc_boot() to return immediately when
> > max_huge_pages is 0, avoiding unnecessary CPU cycles and the below
> > log message when hugepages aren't configured in the kernel command
> > line.
> > [    3.702280] HugeTLB: allocation took 0ms with hugepage_allocation_threads=32
> > 
> > Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
> > ---
> > diff with v1: adding the reduced log messages in commit header
> > 
> >   mm/hugetlb.c | 3 +++
> >   1 file changed, 3 insertions(+)
> > 
> > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> > index 753f99b..514fab5 100644
> > --- a/mm/hugetlb.c
> > +++ b/mm/hugetlb.c
> > @@ -3654,6 +3654,9 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> >   		return;
> >   	}
> >   
> > +	if (!h->max_huge_pages)
> > +		return;
> > +
> >   	/* do node specific alloc */
> >   	if (hugetlb_hstate_alloc_pages_specific_nodes(h))
> >   		return;
> 
> Looks good.  Could you add stable: ?

Sure, I did that.

A Fixes: would be nice, to tell the -stable maintainers how far back in
time we need this, but the target sommit isn't obvious.