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[Qemu-devel] [PATCH RFC 0/5] making address spaces 64 bit wide
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PATCH RFC 0/5] making address spaces 64 bit wide |
Date: |
Mon, 11 Nov 2013 18:40:47 +0200 |
At the moment, exec ignores high bits in each address,
for efficiency.
This is incorrect: devices can do full 64 bit DMA, it's
only the CPU that is limited by target address space.
Using full 64 bit addresses was clocked at 12% performance
hit on a microbenchmark.
To solve, teach pagetables to skip bits at any level
and not just the lowest level.
This should solve the performance problem (only one line
of code changed on the data path).
I'm still trying to figure out how to measure speed
properly with TCG, sending this out for early feedback and flames.
Michael S. Tsirkin (3):
exec: relace leaf with skip
exec: extend skip field to 3 bits
exec: memory radix tree page level compression
Paolo Bonzini (2):
split definitions for exec.c and translate-all.c radix trees
exec: make address spaces 64-bit wide
translate-all.h | 7 ----
exec.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++---------
translate-all.c | 32 +++++++++-------
3 files changed, 117 insertions(+), 39 deletions(-)
--
MST
- [Qemu-devel] [PATCH RFC 0/5] making address spaces 64 bit wide,
Michael S. Tsirkin <=
- [Qemu-devel] [PATCH RFC 1/5] split definitions for exec.c and translate-all.c radix trees, Michael S. Tsirkin, 2013/11/11
- [Qemu-devel] [PATCH RFC 2/5] exec: make address spaces 64-bit wide, Michael S. Tsirkin, 2013/11/11
- [Qemu-devel] [PATCH RFC 3/5] exec: relace leaf with skip, Michael S. Tsirkin, 2013/11/11
- [Qemu-devel] [PATCH RFC 4/5] exec: extend skip field to 3 bits, Michael S. Tsirkin, 2013/11/11
- [Qemu-devel] [PATCH RFC 5/5] exec: memory radix tree page level compression, Michael S. Tsirkin, 2013/11/11
- Re: [Qemu-devel] [PATCH RFC 0/5] making address spaces 64 bit wide, Paolo Bonzini, 2013/11/11