linux-kernel - Re: [PATCH v2] mm/cma: always check which page cause allocation failure

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] [day] [month] [year] [list]

Date:	Wed, 25 Nov 2015 11:45:57 +0100
From:	Vlastimil Babka <vbabka@...e.cz>
To:	Joonsoo Kim <js1304@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Michal Nazarewicz <mina86@...a86.com>,
	Minchan Kim <minchan@...nel.org>,
	David Rientjes <rientjes@...gle.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, Joonsoo Kim <iamjoonsoo.kim@....com>
Subject: Re: [PATCH v2] mm/cma: always check which page cause allocation
 failure

On 11/25/2015 06:32 AM, Joonsoo Kim wrote:
> Now, we have tracepoint in test_pages_isolated() to notify
> pfn which cannot be isolated. But, in alloc_contig_range(),
> some error path doesn't call test_pages_isolated() so it's still
> hard to know exact pfn that causes allocation failure.
> 
> This patch change this situation by calling test_pages_isolated()
> in almost error path. In allocation failure case, some overhead
> is added by this change, but, allocation failure is really rare
> event so it would not matter.
> 
> In fatal signal pending case, we don't call test_pages_isolated()
> because this failure is intentional one.
> 
> There was a bogus outer_start problem due to unchecked buddy order
> and this patch also fix it. Before this patch, it didn't matter,
> because end result is same thing. But, after this patch,
> tracepoint will report failed pfn so it should be accurate.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>

Acked-by: Vlastimil Babka <vbabka@...e.cz>

--
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/