linux-kernel - Re: [PATCH 03/10] soft-offline: use migrate_pages() instead of migrate_huge

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <874nfqesut.fsf@linux.vnet.ibm.com>
Date:	Mon, 01 Apr 2013 10:43:14 +0530
From:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To:	Michal Hocko <mhocko@...e.cz>
Cc:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>, linux-mm@...ck.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Mel Gorman <mel@....ul.ie>, Hugh Dickins <hughd@...gle.com>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Andi Kleen <andi@...stfloor.org>,
	Hillf Danton <dhillf@...il.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 03/10] soft-offline: use migrate_pages() instead of migrate_huge_page()

Michal Hocko <mhocko@...e.cz> writes:

> On Tue 26-03-13 16:59:40, Aneesh Kumar K.V wrote:
>> Naoya Horiguchi <n-horiguchi@...jp.nec.com> writes:
> [...]
>> > diff --git v3.9-rc3.orig/mm/memory-failure.c v3.9-rc3/mm/memory-failure.c
>> > index df0694c..4e01082 100644
>> > --- v3.9-rc3.orig/mm/memory-failure.c
>> > +++ v3.9-rc3/mm/memory-failure.c
>> > @@ -1467,6 +1467,7 @@ static int soft_offline_huge_page(struct page *page, int flags)
>> >  	int ret;
>> >  	unsigned long pfn = page_to_pfn(page);
>> >  	struct page *hpage = compound_head(page);
>> > +	LIST_HEAD(pagelist);
>> >
>> >  	/*
>> >  	 * This double-check of PageHWPoison is to avoid the race with
>> > @@ -1482,12 +1483,20 @@ static int soft_offline_huge_page(struct page *page, int flags)
>> >  	unlock_page(hpage);
>> >
>> >  	/* Keep page count to indicate a given hugepage is isolated. */
>> > -	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL,
>> > -				MIGRATE_SYNC);
>> > -	put_page(hpage);
>> > +	list_move(&hpage->lru, &pagelist);
>> 
>> we use hpage->lru to add the hpage to h->hugepage_activelist. This will
>> break a hugetlb cgroup removal isn't it ?
>
> This particular part will not break removal because
> hugetlb_cgroup_css_offline loops until hugetlb_cgroup_have_usage is 0.
>

But we still need to hold hugetlb_lock around that right ?

-aneesh

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/