Huge Page Support: Difference between revisions
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=== References === |
=== References === |
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* [http://en.wikipedia.org/wiki/Page_%28computer_memory%29#Huge_pages Wikipedia entry for Huge Pages] |
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* Huge Pages |
* Huge Pages [http://linux-mm.org/HugePages from Linux memory management site] |
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* Huge Page Document |
* Huge Page Document [https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt from Kernel.org] |
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* And the source document for this page: http://zhigang.org/wiki/XenHugePages |
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Revision as of 02:56, 6 May 2015
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This page is new and needs review for accuracy and completeness. |
Huge Pages
- Huge pages are also known as 'superpages' in FreeBSD (or 'large pages' in the Microsoft Windows world)
- Newer AMD64 processors can use 1GB pages in long mode.
- Linux has supported huge pages on several architectures since the 2.6 series via the hugetlbfs filesystem.
- Xen Project supports allocating huge pages for guest. The hypervisor itself doesn't use huge pages.
Using Huge Pages
- Specify the hypervisor boot command line flag `allowsuperpage` (it was called `allowhugepage` before).
- Create the VM with option `superpages = 1`.
Notes:
- This option is for PV guest only; it has no effect to HVM guest.
- With this option, PV guest `memory` and `maxmem` must be 2M aligned. Otherwise the VM cannot be started.
- Specify the Linux boot command line flag `balloon_hugepages`.
- In the guest::
# echo 20 > /proc/sys/vm/nr_hugepages # cat /proc/meminfo ... AnonHugePages: 0 kB HugePages_Total: 20 HugePages_Free: 20 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 1056768 kB DirectMap2M: 0 kB
References
- Wikipedia entry for Huge Pages
- Huge Pages from Linux memory management site
- Huge Page Document from Kernel.org
- And the source document for this page: http://zhigang.org/wiki/XenHugePages
