Re: [QUICKLIST 1/5] Quicklists for page table pages V4

From: Andrew Morton
Date: Sat Mar 24 2007 - 02:22:48 EST


On Fri, 23 Mar 2007 10:54:12 -0700 (PDT) Christoph Lameter <clameter@xxxxxxx> wrote:

> Here are the results of aim9 tests on x86_64. There are some minor performance
> improvements and some fluctuations.

There are a lot of numbers there - what do they tell us?

> 2.6.21-rc4 bare
> 2.6.21-rc4 x86_64 quicklist

So what has changed here? From a quick look it appears that x86_64 is
using get_zeroed_page() for ptes, puds and pmds and is using a custom
quicklist for pgds.

After your patches, x86_64 is using a common quicklist allocator for puds,
pmds and pgds and continues to use get_zeroed_page() for ptes.

Or something totally different, dunno. I tire.


My question is pretty simple: how do we justify the retention of this
custom allocator?

Because simply removing it is the preferable way of fixing the SLUB
problem.
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