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Message-ID: <790b82cc-ea85-3483-6626-8e047260e603@nvidia.com>
Date:   Wed, 16 Feb 2022 21:46:42 -0800
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Subject: Re: [PATCH v4 4/4] mm: Rework swap handling of zap_pte_range
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To:     Peter Xu <peterx@redhat.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A . Shutemov" <kirill@shutemov.name>,
        Matthew Wilcox <willy@infradead.org>,
        Yang Shi <shy828301@gmail.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Alistair Popple <apopple@nvidia.com>,
        David Hildenbrand <david@redhat.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Hugh Dickins <hughd@google.com>
References: <20220216094810.60572-1-peterx@redhat.com>
 <20220216094810.60572-5-peterx@redhat.com>
 <b04fabea-6216-3808-44e8-0a2125bf0230@nvidia.com>
 <Yg3VHr28m0739GQE@xz-m1.local>
From:   John Hubbard <jhubbard@nvidia.com>
In-Reply-To: <Yg3VHr28m0739GQE@xz-m1.local>
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On 2/16/22 20:54, Peter Xu wrote:
> On Wed, Feb 16, 2022 at 07:25:14PM -0800, John Hubbard wrote:
>> On 2/16/22 1:48 AM, Peter Xu wrote:
>>> Clean the code up by merging the device private/exclusive swap entry handling
>>> with the rest, then we merge the pte clear operation too.
>>
>> Maybe also mention that you reduced the code duplication in the
>> is_device_private_entry() area, by letting it fall through to the common
>> pte_clear_not_present_full() at the end of the loop? Since you're listing
>> the other changes, that one seems worth mentioning.
> 
> Isn't that the "we merge the pte clear operation" part? :)
>

Somehow that part wasn't as clear to me, but...

> I can add another sentence to it, if it looks better to you:
> 
> ---8<---
> Clean the code up by merging the device private/exclusive swap entry
> handling with the rest, then we merge the pte clear operation too.  We do
> it by letting the private/exclusive block fall through to the last call to
> pte_clear_not_present_full().
> ---8<---
> 

...no need to change anything here. I just wanted the list to be complete,
and it is.


thanks,
-- 
John Hubbard
NVIDIA