From: Vladimir Murzin <vladimir.murzin@arm.com>
To: Bojan Prtvar <bojan.prtvar@rt-rk.com>, linux-mm@kvack.org
Subject: Re: memtest help
Date: Fri, 29 Apr 2016 10:22:06 +0100 [thread overview]
Message-ID: <572327BE.7030606@arm.com> (raw)
In-Reply-To: <57223D77.6020502@rt-rk.com>
On 28/04/16 17:42, Bojan Prtvar wrote:
> Hello everyone,
>
> I need to test all RAM cells on a linux ARM embedded system. My use case
> is very similar to the one described in [1] expect the fact I also have
> strong requirements on minimizing the boot time impact.
> Instead of doing that from the bootloader, I decided to evaluate the
> linux memtest feature introduced with [2].
>
> My questions are:
>
> 1)
> Does the early_memtest() as called in [3] really covers *all* RAM cells?
No.
>
> 2)
> As memtest happens very early in boot stage, what primitives I can use
> to measure duration of early_memtest()? Are there any known heuristics?
> I need to test ~2GB of RAM.
> This is my major concern.
Stopwatch?
>
> 3)
> It seems reasonable to expose the number of detected bad cells to user
> space. I was thinking about sysfs. Are the patches welcomed?
>
$ dmesg | grep "bad mem"
Cheers
Vladimir
> [1]
> http://www.linuxforums.org/forum/newbie/173847-how-do-memory-ram-test-when-linux-running.html
>
> [2]
> http://lkml.iu.edu/hypermail/linux/kernel/1503.1/00566.html
> [3]
> http://lxr.free-electrons.com/source/arch/arm/mm/init.c#L291
>
> Thanks,
> Bojan
>
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prev parent reply other threads:[~2016-04-29 9:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-28 16:42 memtest help Bojan Prtvar
2016-04-29 9:22 ` Vladimir Murzin [this message]
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