linux-kernel - Re: [External] [PATCH 5/8] hugetlb: call update_and_free_page without hugetlb

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Message-ID: <31334184-01d8-a0d5-d3a3-6bfad08f2eb7@oracle.com>
Date:   Sun, 28 Mar 2021 14:40:35 -0700
From:   Mike Kravetz <mike.kravetz@...cle.com>
To:     Muchun Song <songmuchun@...edance.com>
Cc:     Linux Memory Management List <linux-mm@...ck.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Roman Gushchin <guro@...com>, Michal Hocko <mhocko@...e.com>,
        Shakeel Butt <shakeelb@...gle.com>,
        Oscar Salvador <osalvador@...e.de>,
        David Hildenbrand <david@...hat.com>,
        David Rientjes <rientjes@...gle.com>,
        Miaohe Lin <linmiaohe@...wei.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Matthew Wilcox <willy@...radead.org>,
        HORIGUCHI NAOYA <naoya.horiguchi@....com>,
        "Aneesh Kumar K . V" <aneesh.kumar@...ux.ibm.com>,
        Waiman Long <longman@...hat.com>, Peter Xu <peterx@...hat.com>,
        Mina Almasry <almasrymina@...gle.com>,
        Hillf Danton <hdanton@...a.com>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [External] [PATCH 5/8] hugetlb: call update_and_free_page without
 hugetlb_lock

On 3/26/21 11:54 PM, Muchun Song wrote:
> On Thu, Mar 25, 2021 at 8:29 AM Mike Kravetz <mike.kravetz@...cle.com> wrote:
>>
>> With the introduction of remove_hugetlb_page(), there is no need for
>> update_and_free_page to hold the hugetlb lock.  Change all callers to
>> drop the lock before calling.
>>
>> With additional code modifications, this will allow loops which decrease
>> the huge page pool to drop the hugetlb_lock with each page to reduce
>> long hold times.
>>
>> The ugly unlock/lock cycle in free_pool_huge_page will be removed in
>> a subsequent patch which restructures free_pool_huge_page.
>>
>> Signed-off-by: Mike Kravetz <mike.kravetz@...cle.com>
> 
> Reviewed-by: Muchun Song <songmuchun@...edance.com>
> 
> Some nits below.

Thanks Muchun,

I agree with all your suggestions below, and will include modifications
in the next version.
-- 
Mike Kravetz