linux-kernel - Re: [PATCH 3/4] Check whether pages are poisoned before copying

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: <20110317164726.GA10696@random.random>
Date:	Thu, 17 Mar 2011 17:47:26 +0100
From:	Andrea Arcangeli <aarcange@...hat.com>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Huang Ying <ying.huang@...el.com>,
	Jin Dongming <jin.dongming@...css.fujitsu.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/4] Check whether pages are poisoned before copying

On Thu, Mar 17, 2011 at 05:27:10PM +0100, Andi Kleen wrote:
> > What I can tell is with the default khugepaged scan rate, the
> > collapse_huge_page will have an impact much smaller than KSM. It could
> > have more impact than KSM if you increase khugepaged load to 100% with
> > sysfs (because of the more memory that is covered by khugepaged
> > compared to only the shared portion of KSM). Then the window gets much
> > bigger, but still minor, if you can't trigger it with the testsuite
> > it's even less likely to ever happen in practice.
> 
> You mean randomly injecting errors?
> That tends to be hard and unreliable -- usually we try to have a 
> specific tester that is not random.

I meant the testsuite using MCE injection, called mce-test. I've run
it a couple of times for some hugetlbfs collision with THP (solved
some time ago).

> The measurement is simple: run the workloads and do some dumps
> with pagetypes and check if the memory with lots of pages 
> has a state that can be handled by memory_failure()
> 
> AFAIK  this hasn't been done so far with THP.

I'm unsure if there's already coverage for it in mce-test yet, the
biggest test I run was hugetlbfs related (MAP_ANONYMOUS|MAP_HUGETLB or
filebacked or still shm). Surely it'd be good idea to add THP
coverage.
--
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/