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From:   Stefan Roesch <shr@devkernel.io>
To:     David Hildenbrand <david@redhat.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linux-s390@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Rik van Riel <riel@surriel.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@suse.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Janosch Frank <frankja@linux.ibm.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        Shuah Khan <shuah@kernel.org>
Subject: Re: [PATCH v1 1/3] mm/ksm: unmerge and clear VM_MERGEABLE when
 setting PR_SET_MEMORY_MERGE=0
Date:   Fri, 21 Apr 2023 11:28:49 -0700
In-reply-to: <f809162e-4adc-cf9b-35f4-0f1b098ad283@redhat.com>
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David Hildenbrand <david@redhat.com> writes:

>>> I understand we want to keep the name "symmetric" with
>>> ksm_enable_merge_any, but it also unmerges the ksm pages. Do we want to
>>> reflect that in the function name?
>> ksm_disable_merge_any_umerge() is suboptimal.
>> As ksm_disable_merge_any() now reverts what ksm_enable_merge_any() ended
>> up doing, I think it's just fine.
>> (it would be a different story if we'd be using "set" / "clear"
>> terminology instead of "enable" / "disable").
>> We can describe that in the comment.
>>
>>>
>>> Can we add a comment for the function?
>> Can do for symmetry with ksm_enable_merge_any().
>>
>
> +/**
> + * ksm_disable_merge_any - Disable merging on all compatible VMA's of the mm,
> + *                        previously enabled via ksm_enable_merge_any().
> + *
> + * Disabling merging implies unmerging any merged pages, like setting
> + * MADV_UNMERGEABLE would. If unmerging fails, the whole operation fails and
> + * merging on all compatible VMA's remains enabled.
> + *
> + * @mm: Pointer to mm
> + *
> + * Returns 0 on success, otherwise error code
> + */


LGTM

Acked-by: Stefan Roesch <shr@devkernel.io>