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]
Date:	Thu, 06 Mar 2014 01:24:09 -0500
From:	Brian Wong <draconicpenguin1@...oo.com>
To:	linux-kernel@...r.kernel.org
Subject: Re: Linux does not use more than the startup RAM under Hyper-V with
 dynamic memory enabled

On 3/6/2014 1:20 AM, Brian Wong wrote:
> I'm new to LKML, so please don't be too hard on me :)
>
> I'm running Gentoo Linux under Microsoft Client Hyper-V on Windows 8.1
> Pro, and I've noticed some odd behavior with respect to dynamic memory
> (aka memory ballooning). The system will never use more than the startup
> memory defined in the vitual machine's settings.
>
> For example, if I set the startup memory to 512 MB, and enable dynamic
> memory with a minimum of 512 MB and a maximum of 8192 MB, the system
> will never allocate than 512 MB of physical memory, despite Hyper-V
> assigning more memory to the VM and the added memory being visible in
> the output of "free" and "htop". Attempting to use more memory causes
> the system to start paging to swap, rather than actually allocating the
> memory above the startup memory assigned to the VM.
>
> The kernel is built with the full set of Hyper-V drivers, including the
> key "Microsoft Hyper-V Balloon Driver" as well as memory hot-add and
> hot-remove functionality. This is happening with both the Gentoo-patched
> 3.10.32 kernel and the vanilla 3.12.5 kernel. The host machine has a
> total of 24 GB of memory.
>
> For now, I am working around the issue by starting the VM with the
> startup memory set to the maximum and letting Hyper-V take the usused
> memory back when it is not in use. The VM will then get the extra memory
> when it needs it.
>
> Have I encountered a bug in the Hyper-V balloon driver?
>

Just a correction: the vanilla kernel version is 3.13.5, not 3.12.5. 
Sorry for any confusion.

-- 
Brian Wong
http://www.fierydragonlord.com
--
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/

Powered by blists - more mailing lists