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[Qemu-devel] [PATCHv3 0/9] buffer_is_zero / migration optimizations
From: |
Peter Lieven |
Subject: |
[Qemu-devel] [PATCHv3 0/9] buffer_is_zero / migration optimizations |
Date: |
Thu, 21 Mar 2013 16:57:28 +0100 |
this is v3 of my patch series with various optimizations in
zero buffer checking and migration tweaks.
thanks especially to Eric Blake for reviewing.
v3:
- remove asserts, inline functions and add a check
function if buffer_find_nonzero_offset() can be used.
- use above check function in buffer_is_zero() and
find_next_bit().
- use buffer_is_nonzero_offset() directly to find
zero pages. we know that all requirements are met
for memory pages.
- fix C89 violation in buffer_is_zero().
- avoid derefencing p in ram_save_block() if we already
know the page is zero.
- fix initialization of last_offset in reset_ram_globals().
- avoid skipping pages with offset == 0 in bulk stage in
migration_bitmap_find_and_reset_dirty().
- compared to v1 check for zero pages also after bulk
ram migration as there are guests (e.g. Windows) which
zero out large amount of memory while running.
v2:
- fix description, add trivial zero check and add asserts
to buffer_find_nonzero_offset.
- add a constant for the unroll factor of buffer_find_nonzero_offset
- replace is_dup_page() by buffer_is_zero()
- added test results to xbzrle patch
- optimize descriptions
Peter Lieven (9):
move vector definitions to qemu-common.h
cutils: add a function to find non-zero content in a buffer
buffer_is_zero: use vector optimizations if possible
bitops: use vector algorithm to optimize find_next_bit()
migration: search for zero instead of dup pages
migration: add an indicator for bulk state of ram migration
migration: do not sent zero pages in bulk stage
migration: do not search dirty pages in bulk stage
migration: use XBZRLE only after bulk stage
arch_init.c | 62 ++++++++++++++++++-------------------------------
include/qemu-common.h | 27 +++++++++++++++++++++
util/bitops.c | 22 +++++++++++++++---
util/cutils.c | 55 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 123 insertions(+), 43 deletions(-)
--
1.7.9.5
- [Qemu-devel] [PATCHv3 0/9] buffer_is_zero / migration optimizations,
Peter Lieven <=