From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
v5:
- rename global_dirty_log to global_dirty_tracking on Peter's advice
- make global_dirty_tracking a bitmask:
1. add assert statement to ensure starting dirty tracking repeatly
not allowed.
2. add assert statement to ensure dirty tracking cannot be stopped
without having been started.
- protecting dirty rate stat info:
1. drop the mutext for protecting dirty rate introduced in version 4
2. change the code block in query_dirty_rate_info so that requirements
of "safe racing" to the dirty rate stat can be meet
- make the helper function "record_dirtypages" inline and change
the global var dirty_pages to local var
- free DirtyRateVcpuList in case of memory leak
please review, thanks a lot.
v4:
- make global_dirty_log a bitmask:
1. add comments about dirty log bitmask
2. use assert statement to check validity of flags
3. add trace to log bitmask changes
- introduce mode option to show what method calculation should be used,
also, export mode option in the as last commmit
- split cleanup and init of dirty rate stat and move it in the main
thread
- change the fields of DirtyPageRecord to uint64_t type so that we
can calculation the increased dirty pages with the formula
as Peter's advice: dirty pages = end_pages - start_pages
- introduce mutex to protect dirty rate stat info
- adjust order of registering thread
- drop the memory free callback
this version modify some code on Peter's advice, reference to:
https://lore.kernel.org/qemu-devel/YL5nNYXmrqMlXF3v@t490s/
thanks again.
v3:
- pick up "migration/dirtyrate: make sample page count configurable" to
make patchset apply master correctly
v2:
- rebase to "migration/dirtyrate: make sample page count configurable"
- rename "vcpu" to "per_vcpu" to show the per-vcpu method
- squash patch 5/6 into a single one, squash patch 1/2 also
- pick up "hmp: Add "calc_dirty_rate" and "info dirty_rate" cmds"
- make global_dirty_log a bitmask to make sure both migration and dirty
could not intefer with each other
- add memory free callback to prevent memory leaking
the most different of v2 fron v1 is that we make the global_dirty_log a
bitmask. the reason is dirty rate measurement may start or stop dirty
logging during calculation. this conflict with migration because stop
dirty log make migration leave dirty pages out then that'll be a
problem.
make global_dirty_log a bitmask can let both migration and dirty
rate measurement work fine. introduce GLOBAL_DIRTY_MIGRATION and
GLOBAL_DIRTY_DIRTY_RATE to distinguish what current dirty log aims
for, migration or dirty rate.
all references to global_dirty_log should be untouched because any bit
set there should justify that global dirty logging is enabled.
Please review, thanks !
v1:
Since the Dirty Ring on QEMU part has been merged recently, how to use
this feature is under consideration.
In the scene of migration, it is valuable to provide a more accurante
interface to track dirty memory than existing one, so that the upper
layer application can make a wise decision, or whatever. More
importantly,
dirtyrate info at the granualrity of vcpu could provide a possibility to
make migration convergent by imposing restriction on vcpu. With Dirty
Ring, we can calculate dirtyrate efficiently and cheaply.
The old interface implemented by sampling pages, it consumes cpu
resource, and the larger guest memory size become, the more cpu resource
it consumes, namely, hard to scale. New interface has no such drawback.
Please review, thanks !
Best Regards !
Hyman Huang(黄勇) (6):
memory: rename global_dirty_log to global_dirty_tracking
memory: make global_dirty_tracking a bitmask
migration/dirtyrate: introduce struct and adjust DirtyRateStat
migration/dirtyrate: adjust order of registering thread
migration/dirtyrate: move init step of calculation to main thread
migration/dirtyrate: implement dirty-ring dirtyrate calculation
hmp-commands.hx | 7 +-
include/exec/memory.h | 18 +++-
include/exec/ram_addr.h | 4 +-
migration/dirtyrate.c | 260 +++++++++++++++++++++++++++++++++++++++++-------
migration/dirtyrate.h | 19 +++-
migration/ram.c | 8 +-
migration/trace-events | 2 +
qapi/migration.json | 46 ++++++++-
softmmu/memory.c | 36 +++++--
softmmu/trace-events | 1 +
10 files changed, 339 insertions(+), 62 deletions(-)
--
1.8.3.1