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Date:   Wed, 14 Apr 2021 06:54:23 +0200
From:   Oscar Salvador <osalvador@suse.de>
To:     Mike Kravetz <mike.kravetz@oracle.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        David Hildenbrand <david@redhat.com>,
        Michal Hocko <mhocko@kernel.org>,
        Muchun Song <songmuchun@bytedance.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 5/7] mm: Make alloc_contig_range handle free hugetlb
 pages
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References: <20210413104747.12177-1-osalvador@suse.de>
 <20210413104747.12177-6-osalvador@suse.de>
 <338f73f5-cff6-61c1-5252-01d9b30be627@oracle.com>
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On Tue, Apr 13, 2021 at 03:29:02PM -0700, Mike Kravetz wrote:
> >   spin_lock_irq(hugetlb_lock)
> >   1) update_and_free_page
> >        PageHuge() == F
> >        __free_pages()
> >   2) enqueue_huge_page
> >        SetPageHugeFreed()
> >   spin_unlock(&hugetlb_lock)
> 
> Very small nit, the above should be spin_unlock_irq(&hugetlb_lock)

Right, I missed it somehow.

> > +	/*
> > +	 * The page might have been dissolved from under our feet, so make sure
> > +	 * to carefully check the state under the lock.
> > +	 * Return success when racing as if we dissolved the page ourselves.
> > +	 */
> > +	spin_lock_irq(&hugetlb_lock);
> > +	if (PageHuge(page)) {
> > +		head = compound_head(page);
> > +		h = page_hstate(head);
> > +	} else {
> > +		spin_unlock(&hugetlb_lock);
> 
> Should be be spin_unlock_irq(&hugetlb_lock);
> 
> Other than that, it looks good.

Yeah, I will amend it in the next version.

Thanks Mike!


-- 
Oscar Salvador
SUSE L3