From: Michal Hocko <mhocko@suse.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>,
Oscar Salvador <osalvador@suse.de>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Muchun Song <songmuchun@bytedance.com>,
David Hildenbrand <david@redhat.com>,
Matthew Wilcox <willy@infradead.org>,
Miaohe Lin <linmiaohe@huawei.com>
Subject: Re: [PATCH v3 3/5] hugetlb: only set HPageMigratable for migratable hstates
Date: Fri, 29 Jan 2021 10:09:25 +0100 [thread overview]
Message-ID: <YBPQxTaOXBSsjWDE@dhcp22.suse.cz> (raw)
In-Reply-To: <20210128141531.17fec31e6075fe0eb6e33683@linux-foundation.org>
On Thu 28-01-21 14:15:31, Andrew Morton wrote:
> On Thu, 28 Jan 2021 14:00:29 -0800 Mike Kravetz <mike.kravetz@oracle.com> wrote:
>
> > On 1/28/21 1:37 PM, Andrew Morton wrote:
> > > On Thu, 28 Jan 2021 06:52:21 +0100 Oscar Salvador <osalvador@suse.de> wrote:
> > >
> > >> On Wed, Jan 27, 2021 at 03:36:41PM -0800, Mike Kravetz wrote:
> > >>> Yes, this patch is somewhat optional. It should be a minor improvement
> > >>> in cases where we are dealing with hpages in a non-migratable hstate.
> > >>> Although, I do not believe this is the common case.
> > >>>
> > >>> The real reason for even looking into this was a comment by Oscar. With
> > >>> the name change to HPageMigratable, it implies that the page is migratable.
> > >>> However, this is not the case if the page's hstate does not support migration.
> > >>> So, if we check the hstate when setting the flag we can eliminate those
> > >>> cases where the page is certainly not migratable.
> > >>>
> > >>> I don't really love this patch. It has minimal functional value.
> > >>>
> > >>> Oscar, what do you think about dropping this?
> > >>
> > >> Yeah, I remember this topic arose during a discussion of patch#2 in the
> > >> early versions, about whether the renaming to HPageMigratable made
> > >> sense.
> > >>
> > >> Back then I thought that we could have this in one place at fault-path [1],
> > >> which should have made this prettier, but it is not the case.
> > >> True is that the optimization is little, so I am fine with dropping this
> > >> patch.
> > >
> > > I've dropped it.
> >
> > Thanks Andrew.
> >
> > Michal suggested that comments describing synchronization be added for each
> > flag. Since I did 'one patch per flag', that would be an update to each patch.
> > Or, I could simply add a patch to update the comment block based on what you
> > already have.
> >
> > Let me know what is best/easiest for you.
>
> I guess just one patch is best for reviewers. Then I'll split up into
> a sprinkle of -fix patches if I'm feeling energetic ;)
A single patch on top should be just fine. It is not like this would be
a bisectability breaker.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2021-01-29 9:09 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-22 19:52 [PATCH v3 0/5] create hugetlb flags to consolidate state Mike Kravetz
2021-01-22 19:52 ` [PATCH v3 1/5] hugetlb: use page.private for hugetlb specific page flags Mike Kravetz
2021-01-26 8:17 ` Oscar Salvador
2021-01-27 10:20 ` Michal Hocko
2021-01-27 23:01 ` Mike Kravetz
2021-01-27 10:26 ` Michal Hocko
2021-01-22 19:52 ` [PATCH v3 2/5] hugetlb: convert page_huge_active() HPageMigratable flag Mike Kravetz
2021-01-27 10:25 ` Michal Hocko
2021-01-27 23:27 ` Mike Kravetz
2021-01-22 19:52 ` [PATCH v3 3/5] hugetlb: only set HPageMigratable for migratable hstates Mike Kravetz
2021-01-26 8:20 ` Oscar Salvador
2021-01-27 10:35 ` Michal Hocko
2021-01-27 23:36 ` Mike Kravetz
2021-01-28 5:52 ` Oscar Salvador
2021-01-28 21:37 ` Andrew Morton
2021-01-28 22:00 ` Mike Kravetz
2021-01-28 22:15 ` Andrew Morton
2021-01-29 9:09 ` Michal Hocko [this message]
2021-01-29 18:46 ` Mike Kravetz
2021-02-01 11:49 ` Michal Hocko
2021-02-04 1:11 ` Mike Kravetz
2021-01-22 19:52 ` [PATCH v3 4/5] hugetlb: convert PageHugeTemporary() to HPageTemporary flag Mike Kravetz
2021-01-23 3:15 ` [External] " Muchun Song
2021-01-27 10:39 ` Michal Hocko
2021-01-22 19:52 ` [PATCH v3 5/5] hugetlb: convert PageHugeFreed to HPageFreed flag Mike Kravetz
2021-01-27 10:41 ` Michal Hocko
2021-01-27 23:37 ` Mike Kravetz
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