From: Michal Hocko <mhocko@kernel.org>
To: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: 'Vlastimil Babka' <vbabka@suse.cz>,
'Mel Gorman' <mgorman@techsingularity.net>,
'Andrew Morton' <akpm@linux-foundation.org>,
'Christoph Lameter' <cl@linux.com>,
'Johannes Weiner' <hannes@cmpxchg.org>,
'Jesper Dangaard Brouer' <brouer@redhat.com>,
'Linux-MM' <linux-mm@kvack.org>,
'Linux-Kernel' <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] mm, page_alloc: Keep pcp count and list contents in sync if struct page is corrupted
Date: Fri, 2 Dec 2016 11:04:11 +0100 [thread overview]
Message-ID: <20161202100411.GG6830@dhcp22.suse.cz> (raw)
In-Reply-To: <01f201d24c7e$ac04ed40$040ec7c0$@alibaba-inc.com>
On Fri 02-12-16 17:30:07, Hillf Danton wrote:
[...]
> > >> @@ -2217,13 +2217,14 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
> > >> else
> > >> list_add_tail(&page->lru, list);
> > >> list = &page->lru;
> > >> + alloced++;
> > >> if (is_migrate_cma(get_pcppage_migratetype(page)))
> > >> __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
> > >> -(1 << order));
> > >> }
> > >> __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
> > >
> > > Now i is a pure index, yes?
> >
> > No, even if a page fails the check_pcp_refill() check and is not
> > "allocated", it is also no longer a free page, so it's correct to
> > subtract it from NR_FREE_PAGES.
> >
> Yes, we can allocate free page next time.
No we cannot. The page is gone from the free list. We have effectively
leaked it.
--
Michal Hocko
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: "'Vlastimil Babka'" <vbabka@suse.cz>,
"'Mel Gorman'" <mgorman@techsingularity.net>,
"'Andrew Morton'" <akpm@linux-foundation.org>,
"'Christoph Lameter'" <cl@linux.com>,
"'Johannes Weiner'" <hannes@cmpxchg.org>,
"'Jesper Dangaard Brouer'" <brouer@redhat.com>,
"'Linux-MM'" <linux-mm@kvack.org>,
"'Linux-Kernel'" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] mm, page_alloc: Keep pcp count and list contents in sync if struct page is corrupted
Date: Fri, 2 Dec 2016 11:04:11 +0100 [thread overview]
Message-ID: <20161202100411.GG6830@dhcp22.suse.cz> (raw)
In-Reply-To: <01f201d24c7e$ac04ed40$040ec7c0$@alibaba-inc.com>
On Fri 02-12-16 17:30:07, Hillf Danton wrote:
[...]
> > >> @@ -2217,13 +2217,14 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
> > >> else
> > >> list_add_tail(&page->lru, list);
> > >> list = &page->lru;
> > >> + alloced++;
> > >> if (is_migrate_cma(get_pcppage_migratetype(page)))
> > >> __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
> > >> -(1 << order));
> > >> }
> > >> __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
> > >
> > > Now i is a pure index, yes?
> >
> > No, even if a page fails the check_pcp_refill() check and is not
> > "allocated", it is also no longer a free page, so it's correct to
> > subtract it from NR_FREE_PAGES.
> >
> Yes, we can allocate free page next time.
No we cannot. The page is gone from the free list. We have effectively
leaked it.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2016-12-02 10:04 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 0:22 [PATCH 0/2] High-order per-cpu cache v5 Mel Gorman
2016-12-02 0:22 ` Mel Gorman
2016-12-02 0:22 ` [PATCH 1/2] mm, page_alloc: Keep pcp count and list contents in sync if struct page is corrupted Mel Gorman
2016-12-02 0:22 ` Mel Gorman
2016-12-02 3:47 ` Hillf Danton
2016-12-02 3:47 ` Hillf Danton
2016-12-02 6:19 ` Vlastimil Babka
2016-12-02 6:19 ` Vlastimil Babka
2016-12-02 9:30 ` Hillf Danton
2016-12-02 9:30 ` Hillf Danton
2016-12-02 10:04 ` Michal Hocko [this message]
2016-12-02 10:04 ` Michal Hocko
2016-12-02 11:02 ` Mel Gorman
2016-12-02 11:02 ` Mel Gorman
2016-12-02 8:12 ` Michal Hocko
2016-12-02 8:12 ` Michal Hocko
2016-12-02 9:49 ` Mel Gorman
2016-12-02 9:49 ` Mel Gorman
2016-12-02 10:03 ` Michal Hocko
2016-12-02 10:03 ` Michal Hocko
2016-12-02 0:22 ` [PATCH 2/2] mm: page_alloc: High-order per-cpu page allocator v5 Mel Gorman
2016-12-02 0:22 ` Mel Gorman
2016-12-02 6:03 ` Joonsoo Kim
2016-12-02 6:03 ` Joonsoo Kim
2016-12-02 8:21 ` Michal Hocko
2016-12-02 8:21 ` Michal Hocko
2016-12-05 3:10 ` Joonsoo Kim
2016-12-05 3:10 ` Joonsoo Kim
2016-12-02 9:04 ` Mel Gorman
2016-12-02 9:04 ` Mel Gorman
2016-12-05 3:06 ` Joonsoo Kim
2016-12-05 3:06 ` Joonsoo Kim
2016-12-05 9:57 ` Mel Gorman
2016-12-05 9:57 ` Mel Gorman
2016-12-06 2:43 ` Joonsoo Kim
2016-12-06 2:43 ` Joonsoo Kim
2016-12-06 13:53 ` Mel Gorman
2016-12-06 13:53 ` Mel Gorman
2016-12-02 8:25 ` Michal Hocko
2016-12-02 8:25 ` Michal Hocko
-- strict thread matches above, loose matches on Subject: below --
2016-12-02 11:29 [PATCH 0/2] High-order per-cpu cache v6 Mel Gorman
2016-12-02 11:29 ` [PATCH 1/2] mm, page_alloc: Keep pcp count and list contents in sync if struct page is corrupted Mel Gorman
2016-12-02 11:29 ` Mel Gorman
2016-12-02 11:53 ` Vlastimil Babka
2016-12-02 11:53 ` Vlastimil Babka
2016-12-02 13:15 ` Michal Hocko
2016-12-02 13:15 ` Michal Hocko
2016-12-05 3:39 ` Hillf Danton
2016-12-05 3:39 ` Hillf Danton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161202100411.GG6830@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=brouer@redhat.com \
--cc=cl@linux.com \
--cc=hannes@cmpxchg.org \
--cc=hillf.zj@alibaba-inc.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.