Re: [PATCH 0 of 9] x86/smp function calls: convert x86 tlb flushes to use function calls [POST 2]

From: Andi Kleen
Date: Tue Aug 19 2008 - 06:29:24 EST


> I'm especially sore about mmap because I have a customer with a
> database that uses a lot of mmap/munmap and those calls have slowed
> down something like 50%(!!) from 2.6.early to 2.6.late.

These are small mmaps right? Also in this case no kmalloc should
be needed anyways.

AFAIK mmap flushing hasn't changed much in 2.6 and it tends
to batch well anyways in this case (unlike vmscan swapping). I would be
careful to really optimize the real culprits which are likely elsewhere.

-Andi
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