[2.4] [PATCH] [RFC] Increasing MAX_ORDER for large mem configs

[Olof Johansson]

There's a variable defined that will override MAX_ORDER to what it's set
at. ia64 uses it whenever they have large pages enabled.

For us, in some cases, it's very beneficial to set it: to get larger
dentry/buffer/inode hash tables for very large mem configs.

Attached patch ups the default from order 11. There's a risk of negative
impact for some small to mid-size mem configs, since the hashes might
take more memory on the system, but it's at the same time supposed to be
controlled by total amount of ram (and capped at MAX_ORDER).


With this, does anyone have concerns with this increase? Would someone
be willing to try booting a small (iSeries?) config to make sure it
behaves ok? I don't have access to one myself.



Thanks,

-Olof

--
Olof Johansson                                        Office: 4F005/905
pSeries Linux Development                             IBM Systems Group
Email: olof at austin.ibm.com                          Phone: 512-838-9858
All opinions are my own and not those of IBM
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