Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
Date:   Fri, 4 Mar 2022 19:06:37 +0100
From:   Oleg Nesterov <oleg@redhat.com>
To:     Hugh Dickins <hughd@google.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Liam Howlett <liam.howlett@oracle.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH mmotm] mempolicy: mbind_range() set_policy() after
 vma_merge()
Message-ID: <20220304180636.GD19636@redhat.com>
References: <319e4db9-64ae-4bca-92f0-ade85d342ff@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <319e4db9-64ae-4bca-92f0-ade85d342ff@google.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Precedence: bulk

On 03/03, Hugh Dickins wrote:
>
> Just delete that optimization now (though it could be made conditional
> on vma not having a set_policy).  Also remove the "next" variable:
> it turned out to be blameless, but also pointless.
>
> Fixes: 3964acd0dbec ("mm: mempolicy: fix mbind_range() && vma_adjust() interaction")

I can't believe I ever looked at this code ;)

Acked-by: Oleg Nesterov <oleg@redhat.com>


offtopic question... can't vma_replace_policy() check vm_ops && vm_ops->set_policy
at the start, before mpol_dup() ?

Oleg.