Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 4 Jan 2023 15:04:26 -0500
From:   Peter Xu <peterx@redhat.com>
To:     James Houghton <jthoughton@google.com>
Cc:     Mike Kravetz <mike.kravetz@oracle.com>,
        Muchun Song <songmuchun@bytedance.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] hugetlb: unshare some PMDs when splitting VMAs
Message-ID: <Y7XbymU+hy6ZJO+/@x1n>
References: <20230101230042.244286-1-jthoughton@google.com>
 <Y7S0lDCeBYLMHBvR@x1n>
 <CADrL8HWSym93=yNpTUdWebOEzUOTR2ffbfUk04XdK6O+PNJNoA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <CADrL8HWSym93=yNpTUdWebOEzUOTR2ffbfUk04XdK6O+PNJNoA@mail.gmail.com>
Precedence: bulk

On Wed, Jan 04, 2023 at 07:34:00PM +0000, James Houghton wrote:
> How about:
> 
> /*
>  * PMD sharing is only possible for PUD_SIZE-aligned address ranges
>  * in HugeTLB VMAs. If we will lose PUD_SIZE alignment due to this split,
>  * unshare PMDs in the PUD_SIZE interval surrounding addr now.
>  */

Even better, thanks.

-- 
Peter Xu