From: Qian Cai <cai@lca.pw>
To: Anshuman Khandual <Anshuman.Khandual@arm.com>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
Oscar Salvador <osalvador@suse.de>,
Mel Gorman <mgorman@techsingularity.net>,
Mike Rapoport <rppt@linux.ibm.com>,
Dan Williams <dan.j.williams@intel.com>,
Pavel Tatashin <pavel.tatashin@microsoft.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/page_alloc: Add a reason for reserved pages in has_unmovable_pages()
Date: Thu, 3 Oct 2019 08:14:40 -0400 [thread overview]
Message-ID: <6A58E80B-7A5F-4CAD-ACF1-89BCCBE4D3B1@lca.pw> (raw)
In-Reply-To: <49fa7dea-00ac-155f-e7b7-eeca206556b5@arm.com>
> On Oct 3, 2019, at 8:01 AM, Anshuman Khandual <Anshuman.Khandual@arm.com> wrote:
>
> Will something like this be better ?
Not really. dump_page() will dump PageCompound information anyway, so it is trivial to figure out if went in that path.
> hugepage_migration_supported() has got
> uncertainty depending on platform and huge page size.
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 15c2050c629b..8dbc86696515 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8175,7 +8175,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> unsigned long found;
> unsigned long iter = 0;
> unsigned long pfn = page_to_pfn(page);
> - const char *reason = "unmovable page";
> + const char *reason;
>
> /*
> * TODO we could make this much more efficient by not checking every
> @@ -8194,7 +8194,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> if (is_migrate_cma(migratetype))
> return false;
>
> - reason = "CMA page";
> + reason = "Unmovable CMA page";
> goto unmovable;
> }
>
> @@ -8206,8 +8206,10 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
>
> page = pfn_to_page(check);
>
> - if (PageReserved(page))
> + if (PageReserved(page)) {
> + reason = "Unmovable reserved page";
> goto unmovable;
> + }
>
> /*
> * If the zone is movable and we have ruled out all reserved
> @@ -8226,8 +8228,10 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> struct page *head = compound_head(page);
> unsigned int skip_pages;
>
> - if (!hugepage_migration_supported(page_hstate(head)))
> + if (!hugepage_migration_supported(page_hstate(head))) {
> + reason = "Unmovable HugeTLB page";
> goto unmovable;
> + }
>
> skip_pages = compound_nr(head) - (page - head);
> iter += skip_pages - 1;
> @@ -8271,8 +8275,10 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> * is set to both of a memory hole page and a _used_ kernel
> * page at boot.
> */
> - if (found > count)
> + if (found > count) {
> + reason = "Unmovable non-LRU page";
> goto unmovable;
> + }
> }
> return false;
> unmovable:
next prev parent reply other threads:[~2019-10-03 12:14 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-03 8:10 Anshuman Khandual
2019-10-03 9:05 ` Qian Cai
2019-10-03 9:32 ` Anshuman Khandual
2019-10-03 9:53 ` Anshuman Khandual
2019-10-03 11:19 ` Qian Cai
2019-10-03 11:32 ` Anshuman Khandual
2019-10-03 11:50 ` Qian Cai
2019-10-03 12:02 ` Anshuman Khandual
2019-10-03 12:14 ` Qian Cai [this message]
2019-10-04 8:25 ` David Hildenbrand
2020-01-14 8:19 ` Anshuman Khandual
2020-01-14 8:30 ` David Hildenbrand
2020-01-14 9:10 ` Michal Hocko
2020-01-14 10:23 ` Vlastimil Babka
2020-01-14 11:03 ` Anshuman Khandual
2020-01-14 11:32 ` Michal Hocko
2020-01-14 12:04 ` [PATCH] mm, debug: always print flags in dump_page() Vlastimil Babka
2020-01-14 13:35 ` Michal Hocko
2020-01-14 18:22 ` [PATCH] mm/page_alloc: Add a reason for reserved pages in has_unmovable_pages() Ralph Campbell
2019-10-04 10:58 ` Michal Hocko
2019-10-04 11:44 ` Anshuman Khandual
2019-10-04 12:56 ` Qian Cai
2019-10-04 13:07 ` Michal Hocko
2019-10-04 13:30 ` Qian Cai
2019-10-04 13:38 ` Michal Hocko
2019-10-04 13:56 ` Qian Cai
2019-10-04 14:41 ` Michal Hocko
2019-10-05 21:22 ` Andrew Morton
2019-10-05 22:38 ` Qian Cai
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