From: Oscar Salvador <osalvador@suse.de>
To: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Michal Hocko <mhocko@kernel.org>,
Muchun Song <songmuchun@bytedance.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Anshuman Khandual <anshuman.khandual@arm.com>
Subject: Re: [PATCH v4 0/4] Make alloc_contig_range handle Hugetlb pages
Date: Wed, 17 Mar 2021 11:05:23 +0100 [thread overview]
Message-ID: <20210317100518.GA16479@linux> (raw)
In-Reply-To: <01d2ee6a-f0aa-4580-b1f4-f0e8a2ded4f8@redhat.com>
On Wed, Mar 17, 2021 at 10:48:31AM +0100, David Hildenbrand wrote:
> > I was preparing v5, and I wanted to be sure I understood you here.
> >
> > Right you are that the in-use page check can be dropped, as those pages
> > can
> > be migrated away, and the Hugetlb page check can also be dropped since
> > isolate_migratepages_range is now capable of dealing with those kind of
> > pages.
> >
> > > b) Similarly, check for gigantic pages and/or movability/migratability.
> >
> > I lost you here.
> >
> > isolate_or_dissolve_huge_page() already bails out on hugetlb-gigantic
> > pages.
> >
> > Or do you mean to place an upfront check here? (hstate_is_gigantic())?
>
> Yes. But I prefer a) and keeping it simple here -- just doing basic sanity
> checks (online, zone, PageReserved()) that are absolutely necessary.
Ok, I am probably dense as I understood as if you were lean towards having
a) + b).
That is what I have as the last patch of the patchset:
From e97175b7d4970cbdcbafcf8c398f72a571e817b0 Mon Sep 17 00:00:00 2001
From: Oscar Salvador <osalvador@suse.de>
Date: Thu, 18 Mar 2021 05:03:18 +0100
Subject: [PATCH] mm,page_alloc: Drop unnecesary checks from
pfn_range_valid_contig
pfn_range_valid_contig() bails out when it finds an in-use page or a
hugetlb page, among other things.
We can drop the in-use page check since __alloc_contig_pages can migrate
away those pages, and the hugetlb page check can go too since
isolate_migratepages_range is now capable of dealing with hugetlb pages.
Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
mm/page_alloc.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4cb455355f6d..50d73e68b79e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8685,12 +8685,6 @@ static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
if (PageReserved(page))
return false;
-
- if (page_count(page) > 0)
- return false;
-
- if (PageHuge(page))
- return false;
}
return true;
}
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2021-03-17 10:06 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-10 15:08 [PATCH v4 0/4] Make alloc_contig_range handle Hugetlb pages Oscar Salvador
2021-03-10 15:08 ` [PATCH v4 1/4] mm,page_alloc: Bail out earlier on -ENOMEM in alloc_contig_migrate_range Oscar Salvador
2021-03-15 11:00 ` Vlastimil Babka
2021-03-15 11:10 ` David Hildenbrand
2021-03-10 15:08 ` [PATCH v4 2/4] mm,compaction: Let isolate_migratepages_{range,block} return error codes Oscar Salvador
2021-03-15 11:03 ` Vlastimil Babka
2021-03-10 15:08 ` [PATCH v4 3/4] mm: Make alloc_contig_range handle free hugetlb pages Oscar Salvador
2021-03-10 15:08 ` [PATCH v4 4/4] mm: Make alloc_contig_range handle in-use " Oscar Salvador
2021-03-15 9:06 ` [PATCH v4 0/4] Make alloc_contig_range handle Hugetlb pages David Hildenbrand
2021-03-15 10:27 ` Oscar Salvador
2021-03-15 10:28 ` David Hildenbrand
2021-03-17 9:43 ` Oscar Salvador
2021-03-17 9:48 ` David Hildenbrand
2021-03-17 10:05 ` Oscar Salvador [this message]
2021-03-17 10:06 ` Oscar Salvador
2021-03-17 10:07 ` David Hildenbrand
2021-03-15 10:23 ` Oscar Salvador
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