From: Zi Yan <ziy@nvidia.com>
To: Jerome Glisse <jglisse@redhat.com>
Cc: <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Michal Hocko <mhocko@kernel.org>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Mel Gorman <mgorman@techsingularity.net>,
John Hubbard <jhubbard@nvidia.com>,
Mark Hairgrove <mhairgrove@nvidia.com>,
Nitin Gupta <nigupta@nvidia.com>,
David Nellans <dnellans@nvidia.com>
Subject: Re: [RFC PATCH 01/31] mm: migrate: Add exchange_pages to exchange two lists of pages.
Date: Thu, 21 Feb 2019 13:25:02 -0800 [thread overview]
Message-ID: <3AE8BFB7-139B-4312-A0A7-50759BA63362@nvidia.com> (raw)
In-Reply-To: <20190221211038.GC5201@redhat.com>
On 21 Feb 2019, at 13:10, Jerome Glisse wrote:
> On Fri, Feb 15, 2019 at 02:08:26PM -0800, Zi Yan wrote:
>> From: Zi Yan <ziy@nvidia.com>
>>
>> In stead of using two migrate_pages(), a single exchange_pages() would
>> be sufficient and without allocating new pages.
>
> So i believe it would be better to arrange the code differently instead
> of having one function that special case combination, define function for
> each one ie:
> exchange_anon_to_share()
> exchange_anon_to_anon()
> exchange_share_to_share()
>
> Then you could define function to test if a page is in correct states:
> can_exchange_anon_page() // return true if page can be exchange
> can_exchange_share_page()
>
> In fact both of this function can be factor out as common helpers with the
> existing migrate code within migrate.c This way we would have one place
> only where we need to handle all the special casing, test and exceptions.
>
> Other than that i could not spot anything obviously wrong but i did not
> spent enough time to check everything. Re-architecturing the code like
> i propose above would make this a lot easier to review i believe.
>
Thank you for reviewing the patch. Your suggestions are very helpful.
I will restructure the code to help people review it.
>> + from_page_count = page_count(from_page);
>> + from_map_count = page_mapcount(from_page);
>> + to_page_count = page_count(to_page);
>> + to_map_count = page_mapcount(to_page);
>> + from_flags = from_page->flags;
>> + to_flags = to_page->flags;
>> + from_mapping = from_page->mapping;
>> + to_mapping = to_page->mapping;
>> + from_index = from_page->index;
>> + to_index = to_page->index;
>
> Those are not use anywhere ...
Will remove them. Thanks.
--
Best Regards,
Yan Zi
next prev parent reply other threads:[~2019-02-21 21:25 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 22:08 [RFC PATCH 00/31] Generating physically contiguous memory after page allocation Zi Yan
2019-02-15 22:08 ` [RFC PATCH 01/31] mm: migrate: Add exchange_pages to exchange two lists of pages Zi Yan
2019-02-17 11:29 ` Matthew Wilcox
2019-02-18 17:31 ` Zi Yan
2019-02-18 17:42 ` Vlastimil Babka
2019-02-18 17:51 ` Zi Yan
2019-02-18 17:52 ` Matthew Wilcox
2019-02-18 17:59 ` Zi Yan
2019-02-19 7:42 ` Anshuman Khandual
2019-02-19 12:56 ` Matthew Wilcox
2019-02-20 4:38 ` Anshuman Khandual
2019-03-14 2:39 ` Zi Yan
2019-02-21 21:10 ` Jerome Glisse
2019-02-21 21:25 ` Zi Yan [this message]
2019-02-15 22:08 ` [RFC PATCH 02/31] mm: migrate: Add THP exchange support Zi Yan
2019-02-15 22:08 ` [RFC PATCH 03/31] mm: migrate: Add tmpfs " Zi Yan
2019-02-15 22:08 ` [RFC PATCH 04/31] mm: add mem_defrag functionality Zi Yan
2019-02-15 22:08 ` [RFC PATCH 05/31] mem_defrag: split a THP if either src or dst is THP only Zi Yan
2019-02-15 22:08 ` [RFC PATCH 06/31] mm: Make MAX_ORDER configurable in Kconfig for buddy allocator Zi Yan
2019-02-15 22:08 ` [RFC PATCH 07/31] mm: deallocate pages with order > MAX_ORDER Zi Yan
2019-02-15 22:08 ` [RFC PATCH 08/31] mm: add pagechain container for storing multiple pages Zi Yan
2019-02-15 22:08 ` [RFC PATCH 09/31] mm: thp: 1GB anonymous page implementation Zi Yan
2019-02-15 22:08 ` [RFC PATCH 10/31] mm: proc: add 1GB THP kpageflag Zi Yan
2019-02-15 22:08 ` [RFC PATCH 11/31] mm: debug: print compound page order in dump_page() Zi Yan
2019-02-15 22:08 ` [RFC PATCH 12/31] mm: stats: Separate PMD THP and PUD THP stats Zi Yan
2019-02-15 22:08 ` [RFC PATCH 13/31] mm: thp: 1GB THP copy on write implementation Zi Yan
2019-02-15 22:08 ` [RFC PATCH 14/31] mm: thp: handling 1GB THP reference bit Zi Yan
2019-02-15 22:08 ` [RFC PATCH 15/31] mm: thp: add 1GB THP split_huge_pud_page() function Zi Yan
2019-02-15 22:08 ` [RFC PATCH 16/31] mm: thp: check compound_mapcount of PMD-mapped PUD THPs at free time Zi Yan
2019-02-15 22:08 ` [RFC PATCH 17/31] mm: thp: split properly PMD-mapped PUD THP to PTE-mapped PUD THP Zi Yan
2019-02-15 22:08 ` [RFC PATCH 18/31] mm: page_vma_walk: teach it about PMD-mapped " Zi Yan
2019-02-15 22:08 ` [RFC PATCH 19/31] mm: thp: 1GB THP support in try_to_unmap() Zi Yan
2019-02-15 22:08 ` [RFC PATCH 20/31] mm: thp: split 1GB THPs at page reclaim Zi Yan
2019-02-15 22:08 ` [RFC PATCH 21/31] mm: thp: 1GB zero page shrinker Zi Yan
2019-02-15 22:08 ` [RFC PATCH 22/31] mm: thp: 1GB THP follow_p*d_page() support Zi Yan
2019-02-15 22:08 ` [RFC PATCH 23/31] mm: support 1GB THP pagemap support Zi Yan
2019-02-15 22:08 ` [RFC PATCH 24/31] sysctl: add an option to only print the head page virtual address Zi Yan
2019-02-15 22:08 ` [RFC PATCH 25/31] mm: thp: add a knob to enable/disable 1GB THPs Zi Yan
2019-02-15 22:08 ` [RFC PATCH 26/31] mm: thp: promote PTE-mapped THP to PMD-mapped THP Zi Yan
2019-02-15 22:08 ` [RFC PATCH 27/31] mm: thp: promote PMD-mapped PUD pages to PUD-mapped PUD pages Zi Yan
2019-02-15 22:08 ` [RFC PATCH 28/31] mm: vmstats: add page promotion stats Zi Yan
2019-02-15 22:08 ` [RFC PATCH 29/31] mm: madvise: add madvise options to split PMD and PUD THPs Zi Yan
2019-02-15 22:08 ` [RFC PATCH 30/31] mm: mem_defrag: thp: PMD THP and PUD THP in-place promotion support Zi Yan
2019-02-15 22:08 ` [RFC PATCH 31/31] sysctl: toggle to promote PUD-mapped 1GB THP or not Zi Yan
2019-02-20 1:42 ` [RFC PATCH 00/31] Generating physically contiguous memory after page allocation Mike Kravetz
2019-02-20 2:33 ` Zi Yan
2019-02-20 3:18 ` Mike Kravetz
2019-02-20 5:19 ` Zi Yan
2019-02-20 5:27 ` Mike Kravetz
-- strict thread matches above, loose matches on Subject: below --
2019-02-15 22:03 Zi Yan
2019-02-15 22:03 ` [RFC PATCH 01/31] mm: migrate: Add exchange_pages to exchange two lists of pages Zi Yan
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