From: Hyman Huang(黄勇) <huang...@chinatelecom.cn>
the dirtyrate measurement implemented by page-sampling originally, it
is not accurate in some scenarios, so we have introduced dirty-ring
based dirtyrate measurement(maybe it will be merged soon), it fix the
accuracy of page-sampling, and more importantly, it is at the
granualrity of vcpu.
dirty-ring method can be used when dirty-ring enable, as supplementary,
we introduce dirty-bitmap method to calculating dirtyrate when dirty log
enable, so that we can also get the accurate dirtyrate if needed in the
absence of dirty-ring.
three things has done to implement the measurement:
- introduce a fresh new dirty bits named DIRTY_MEMORY_DIRTY_RATE, which
is used to store dirty bitmap after fetching it from kvm. why we do
not reuse the existing DIRTY_MEMORY_MIGRATION dirty bits is we do not
want to interfere with migration of and let implementation clear, this
is also the reason why dirty_memory be split.
DIRTY_MEMORY_DIRTY_RATE dirty bits will be filled when
memory_global_dirty_log_sync executed if GLOBAL_DIRTY_DIRTY_RATE bit
be set in the global_dirty_tracking flag.
- introduce kvm_get_manual_dirty_log_protect function so that we can
probe the protect caps of kvm when calculating.
- implement dirtyrate measurement with dirty bitmap with following step:
1. start the dirty log.
2. probe the protect cap, if KVM_DIRTY_LOG_INITIALLY_SET enable, skip
skip the 1'R and do the reset page protection manually, since kvm
file bitmap with 1 bits if this cap is enabled.
3. clear the DIRTY_MEMORY_DIRTY_RATE dirty bits, prepare to store
the dirty bitmap.
4. start memory_global_dirty_log_sync and fetch dirty bitmap from kvm
5. reap the DIRTY_MEMORY_DIRTY_RATE dirty bits and do the calculation.
this patchset rebases on the commit
"migration/dirtyrate: implement dirty-ring dirtyrate calculation",
since the above feature has not been merged, so we post this patch
for the sake of RFC. ideally, this patshset may be merged after it.
Please, review, thanks !
Best Regards !
Hyman Huang(黄勇) (4):
memory: introduce DIRTY_MEMORY_DIRTY_RATE dirty bits
KVM: introduce kvm_get_manual_dirty_log_protect
memory: introduce DIRTY_MEMORY_DIRTY_RATE dirty bits functions
migration/dirtyrate: implement dirty-bitmap dirtyrate calculation
accel/kvm/kvm-all.c | 6 ++
hmp-commands.hx | 9 +--
include/exec/ram_addr.h | 140 +++++++++++++++++++++++++++++++++++++++++++++-
include/exec/ramlist.h | 9 +--
include/sysemu/kvm.h | 1 +
migration/dirtyrate.c | 146 +++++++++++++++++++++++++++++++++++++++++++++---
migration/trace-events | 2 +
qapi/migration.json | 6 +-
softmmu/physmem.c | 60 ++++++++++++++++++++
9 files changed, 358 insertions(+), 21 deletions(-)
--
1.8.3.1
