From: Ran Wang <ran.wang_1@nxp.com>
To: "linux-mm@kvack.org" <linux-mm@kvack.org>,
Michal Hocko <mhocko@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Reza Arbab <arbab@linux.vnet.ibm.com>,
Yasuaki Ishimatsu <yasu.isimatu@gmail.com>,
"qiuxishi@huawei.com" <qiuxishi@huawei.com>,
Igor Mammedov <imammedo@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, Leo Li <leoyang.li@nxp.com>,
Xiaobo Xie <xiaobo.xie@nxp.com>
Subject: RE: [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages
Date: Mon, 13 Nov 2017 07:33:13 +0000 [thread overview]
Message-ID: <AM3PR04MB14895AE080F9F21E98045D99F12B0@AM3PR04MB1489.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <AM3PR04MB14892A9D6D2FBCE21B8C1F0FF12B0@AM3PR04MB1489.eurprd04.prod.outlook.com>
Hello Michal,
<snip>
> Date: Fri, 13 Oct 2017 14:00:12 +0200
>
> From: Michal Hocko <mhocko@suse.com>
>
> Michael has noticed that the memory offline tries to migrate kernel code
> pages when doing echo 0 > /sys/devices/system/memory/memory0/online
>
> The current implementation will fail the operation after several failed page
> migration attempts but we shouldn't even attempt to migrate that memory
> and fail right away because this memory is clearly not migrateable. This will
> become a real problem when we drop the retry loop counter resp. timeout.
>
> The real problem is in has_unmovable_pages in fact. We should fail if there
> are any non migrateable pages in the area. In orther to guarantee that
> remove the migrate type checks because MIGRATE_MOVABLE is not
> guaranteed to contain only migrateable pages. It is merely a heuristic.
> Similarly MIGRATE_CMA does guarantee that the page allocator doesn't
> allocate any non-migrateable pages from the block but CMA allocations
> themselves are unlikely to migrateable. Therefore remove both checks.
>
> Reported-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> mm/page_alloc.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c index
> 3badcedf96a7..ad0294ab3e4f 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7355,9 +7355,6 @@ bool has_unmovable_pages(struct zone *zone,
> struct page *page, int count,
> */
> if (zone_idx(zone) == ZONE_MOVABLE)
> return false;
> - mt = get_pageblock_migratetype(page);
> - if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
> - return false;
This drop cause DWC3 USB controller fail on initialization with Layerscaper processors
(such as LS1043A) as below:
[ 2.701437] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1
[ 2.710949] cma: cma_alloc: alloc failed, req-size: 1 pages, ret: -16
[ 2.717411] xhci-hcd xhci-hcd.0.auto: can't setup: -12
[ 2.727940] xhci-hcd xhci-hcd.0.auto: USB bus 1 deregistered
[ 2.733607] xhci-hcd: probe of xhci-hcd.0.auto failed with error -12
[ 2.739978] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller
And I notice that someone also reported to you that DWC2 got affected recently,
so do you have the solution now?
Best regards
Ran
>
> pfn = page_to_pfn(page);
> for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
--
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next parent reply other threads:[~2017-11-13 7:33 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AM3PR04MB14892A9D6D2FBCE21B8C1F0FF12B0@AM3PR04MB1489.eurprd04.prod.outlook.com>
2017-11-13 7:33 ` Ran Wang [this message]
2017-11-13 11:02 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Michal Hocko
2017-11-14 6:10 ` Ran Wang
2017-11-14 7:06 ` Michal Hocko
2017-11-14 7:45 ` Ran Wang
2017-10-13 11:58 [PATCH 1/2] mm, memory_hotplug: do not fail offlining too early Michal Hocko
2017-10-13 12:00 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Michal Hocko
2017-10-17 11:41 ` Michael Ellerman
2017-10-17 12:03 ` Michal Hocko
2017-10-17 13:02 ` Vlastimil Babka
2017-10-19 2:51 ` Joonsoo Kim
2017-10-19 7:15 ` Michal Hocko
2017-10-19 7:33 ` Joonsoo Kim
2017-10-19 8:20 ` Michal Hocko
2017-10-19 12:21 ` Michal Hocko
2017-10-20 2:13 ` Joonsoo Kim
2017-10-20 5:59 ` Michal Hocko
2017-10-20 6:50 ` Joonsoo Kim
2017-10-20 7:02 ` Michal Hocko
2017-10-23 5:23 ` Joonsoo Kim
2017-10-23 8:10 ` Michal Hocko
2017-10-24 4:44 ` Joonsoo Kim
2017-10-24 7:44 ` Michal Hocko
2017-10-24 8:12 ` Vlastimil Babka
2017-10-24 12:25 ` Michal Hocko
2017-10-26 2:47 ` Joonsoo Kim
2017-10-26 7:41 ` Michal Hocko
2017-10-20 7:22 ` Xishi Qiu
2017-10-20 8:17 ` Michal Hocko
2017-10-23 5:26 ` Joonsoo Kim
2017-10-26 13:04 ` Vlastimil Babka
2017-10-26 13:59 ` Michal Hocko
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