From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Theurer <habanero@us.ibm.com>
Subject: Why is 'emulate' as good as writable PT's?
Date: Mon, 05 Jun 2006 16:45:50 -0500
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We have been doing some scalability work, and we noticed that forcing 
'emulate' in arch.x86/mm.c achieves the same performance on 1-way dom0.  
For example:

xen-unstable, changeset 10200, i386 with PAE, 1-way

benchmark       xen0   xen0+emulate
-------------   ----   ----
reaim_fserver   4421   4426
reaim_compute   2555   2531
SDET            4759   4810

The reaim benchmarks probably don't have much fork(), where I'd expect 
writable page tables to help, but SDET has a ton of fork+exec.

Could there be situations were we are inadvertently triggering a 
writable page table, where we should just be doing a update_va_mapping()?


-Andrew