linux-kernel - Re: [PATCH 13/18] mm, hugetlb: grab a page_table_lock after page_cache

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: <1375123836-3qms0tvi-mutt-n-horiguchi@ah.jp.nec.com>
Date:	Mon, 29 Jul 2013 14:50:36 -0400
From:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
To:	Joonsoo Kim <iamjoonsoo.kim@....com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Rik van Riel <riel@...hat.com>, Mel Gorman <mgorman@...e.de>,
	Michal Hocko <mhocko@...e.cz>,
	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Hugh Dickins <hughd@...gle.com>,
	Davidlohr Bueso <davidlohr.bueso@...com>,
	David Gibson <david@...son.dropbear.id.au>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, Joonsoo Kim <js1304@...il.com>,
	Wanpeng Li <liwanp@...ux.vnet.ibm.com>,
	Hillf Danton <dhillf@...il.com>
Subject: Re: [PATCH 13/18] mm, hugetlb: grab a page_table_lock after
 page_cache_release

On Mon, Jul 29, 2013 at 02:32:04PM +0900, Joonsoo Kim wrote:
> We don't need to grab a page_table_lock when we try to release a page.
> So, defer to grab a page_table_lock.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>

Reviewed-by: Naoya Horiguchi <n-horiguchi@...jp.nec.com>

> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 35ccdad..255bd9e 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2630,10 +2630,11 @@ retry_avoidcopy:
>  	}
>  	spin_unlock(&mm->page_table_lock);
>  	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> -	/* Caller expects lock to be held */
> -	spin_lock(&mm->page_table_lock);
>  	page_cache_release(new_page);
>  	page_cache_release(old_page);
> +
> +	/* Caller expects lock to be held */
> +	spin_lock(&mm->page_table_lock);
>  	return 0;
>  }
>  
> -- 
> 1.7.9.5
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@...ck.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a>
>
--
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/