Currently query-dirty-rate uses QEMU_CLOCK_REALTIME as
the source for start-time field. This translates to
clock_gettime(CLOCK_MONOTONIC), i.e. number of seconds
since host boot. This is not very useful. The only
reasonable use case of start-time I can imagine is to
check whether previously complet
This patch allows to measure dirty page rate for
sub-second intervals of time. An optional argument is
introduced -- calc-time-unit. For example:
{"execute": "calc-dirty-rate", "arguments":
{"calc-time": 500, "calc-time-unit": "millisecond"} }
Millisecond granularity allows to make predictions w
Introduces alternative argument calc-time-ms, which is the
the same as calc-time but accepts millisecond value.
Millisecond granularity allows to make predictions whether
migration will succeed or not. To do this, calculate dirty
rate with calc-time-ms set to max allowed downtime, convert
measured
Introduces alternative argument calc-time-ms, which is the
the same as calc-time but accepts millisecond value.
Millisecond precision allows to make predictions whether
migration will succeed or not. To do this, calculate dirty
rate with calc-time-ms set to max allowed downtime, convert
measured ra
Some commands (query-migrate and calc-dirty-rate) report values
in units of pages. However, currently the only place where we can
get page size is through query-migrate and only after migration
has started. query-memory-size-summary seems like an appropritate
place where it should be reported inste
Rewrote calc-dirty-rate documentation. Briefly described
different modes of dirty page rate measurement. Added some
examples. Fixed obvious grammar errors.
Signed-off-by: Andrei Gudkov
---
qapi/migration.json | 107 +++-
1 file changed, 77 insertions(+), 3
Some commands (query-migrate and calc-dirty-rate) report values
in units of pages. However, currently the only place where we can
get page size is through query-migrate and only after migration
has started. query-memory-size-summary seems like an appropritate
place where it should be reported inste
In sampling mode, a new metric is collected and reported:
number of pages entirely filled with zeroes.
Signed-off-by: Andrei Gudkov
---
migration/dirtyrate.c | 40 +++-
migration/dirtyrate.h | 1 +
qapi/migration.json | 4
3 files changed, 40 insertio
This significantly reduces overhead of dirty page
rate calculation in sampling mode.
Tested using 32GiB VM on E5-2690 CPU.
With CRC32:
total_pages=8388608 sampled_pages=16384 millis=71
With xxHash:
total_pages=8388608 sampled_pages=16384 millis=14
Signed-off-by: Andrei Gudkov
---
migration/dir
Signed-off-by: Andrei Gudkov
---
MAINTAINERS | 1 +
scripts/predict_migration.py | 283 +++
2 files changed, 284 insertions(+)
create mode 100644 scripts/predict_migration.py
diff --git a/MAINTAINERS b/MAINTAINERS
index fc225e66df..0c578446cf 1
Collect number of dirty pages for progresseively increasing time
periods starting with 125ms up to number of seconds specified with
calc-dirty-rate. Report through qmp and hmp: 1) vector of dirty page
measurements, 2) page size, 3) total number of VM pages, 4) number
of sampled pages.
Signed-off-b
V1 -> V2:
- Extracted CRC32->xxHash into separate commit
- Extacted @n-zero-samples metric into separate commit
- Added description to qapi about connection between
@n-dirty-samples and @periods arrays
- Added (Since ...) tag to new metrics
---
The overall goal of this patch is to be
The overall goal of this patch is to be able to predict time it would
take to migrate VM in precopy mode based on max allowed downtime,
network bandwidth, and metrics collected with "calc-dirty-rate".
Predictor itself is a simple python script that closely follows iterations
of the migration algori
* Collect number of all-zero pages
* Collect vector of number of dirty pages for different time periods
* Report total number of pages, number of sampled pages and page size
* Replaced CRC32 with xxHash for performance reasons
Signed-off-by: Andrei Gudkov
---
migration/dirtyrate.c | 219
Signed-off-by: Andrei Gudkov
---
MAINTAINERS | 1 +
scripts/predict_migration.py | 283 +++
2 files changed, 284 insertions(+)
create mode 100644 scripts/predict_migration.py
diff --git a/MAINTAINERS b/MAINTAINERS
index c6e6549f06..2fb5b6298a 1
15 matches
Mail list logo
