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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 06 Mar 2014 01:20:36 -0500 From: Brian Wong <draconicpenguin1@...oo.com> To: linux-kernel@...r.kernel.org Subject: Linux does not use more than the startup RAM under Hyper-V with dynamic memory enabled 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? -- 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