I am writing to submit a code change aimed at enhancing live migration
acceleration by leveraging the compression capability of the Intel
In-Memory Analytics Accelerator (IAA).
The implementation of the IAA (de)compression code is based on Intel Query
Processing Library (QPL), an open-source software project designed for
high-performance query processing operations on Intel CPUs.
https://github.com/intel/qpl
I would like to summarize the progress so far
1. QPL will be used as an independent compression method like ZLIB and ZSTD,
For the summary of issues compatible with ZLIB, please refer to
docs/devel/migration/qpl-compression.rst
2. The QPL method supports both software path and hardware path (use IAA device)
for multifd migration compression and decompression.
The hardware path is always used first, if the hardware path is unavailable,
it automatically falls back to the software path.
3. Compression accelerator related patches are removed from this patch set and
will be added to the QAT patch set, we will submit separate patches to use
QAT to accelerate ZLIB and ZSTD.
4. Advantages of using IAA accelerator include:
a. Compared with the non-compression method, it can improve downtime
performance without adding additional host resources (both CPU and
network).
b. Compared with using software compression methods (ZSTD/ZLIB), it can
provide high data compression ratio and save a lot of CPU resources
used for compression.
Test condition:
1. Host CPUs are based on Sapphire Rapids
2. VM type, 16 vCPU and 64G memory
3. The source and destination respectively use 4 IAA devices.
4. The workload in the VM
a. all vCPUs are idle state
b. 90% of the virtual machine's memory is used, use silesia to fill
the memory.
The introduction of silesia:
https://sun.aei.polsl.pl//~sdeor/index.php?page=silesia
5. Set "--mem-prealloc" boot parameter on the destination, this parameter
can make IAA performance better and related introduction is added here.
docs/devel/migration/qpl-compression.rst
6. Source migration configuration commands
a. migrate_set_capability multifd on
b. migrate_set_parameter multifd-channels 2/4/8
c. migrate_set_parameter downtime-limit 300
f. migrate_set_parameter max-bandwidth 100G/1G
d. migrate_set_parameter multifd-compression none/qpl/zstd
7. Destination migration configuration commands
a. migrate_set_capability multifd on
b. migrate_set_parameter multifd-channels 2/4/8
c. migrate_set_parameter multifd-compression none/qpl/zstd
Early migration result, each result is the average of three tests
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
| None | of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 8571| 69| 58391| 1896525| 256%|
|BW:100G +-------------+--------+--------+---------+----------+------+
| | 4| 7180| 92| 69736| 1865640| 300%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 7090| 121| 70562| 2174060| 307%|
+--------+-------------+--------+--------+---------+----------+------+
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
|QPL(IAA)| of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 8413| 34| 30067| 1732411| 230%|
|BW:100G +-------------+--------+--------+---------+----------+------+
| | 4| 6559| 32| 38804| 1689954| 450%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 6623| 37| 38745| 1566507| 790%|
+--------+-------------+--------+--------+---------+----------+------+
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
| QPL(SW)| of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 93776| 30| 3050| 500815| 210%|
|BW:100G +-------------+--------+--------+---------+----------+------+
| | 4| 47263| 57| 6068| 1376627| 403%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 24474| 37| 11828| 1951372| 800%|
+--------+-------------+--------+--------+---------+----------+------+
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
| ZSTD | of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 95846| 24| 1800| 521829| 203%|
|BW:100G +-------------+--------+--------+---------+----------+------+
| | 4| 49004| 24| 3529| 890532| 403%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 25574| 32| 6782| 1762222| 800%|
+--------+-------------+--------+--------+---------+----------+------+
When network bandwidth resource is sufficient, QPL can improve downtime
by 2x compared to no compression. In this scenario, with 4/8 channels,
IAA hardware resources are fully used, so adding more channels will not
gain more benefits.
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
| None | of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 57758| 66| 8643| 264617| 34%|
|BW: 1G +-------------+--------+--------+---------+----------+------+
| | 4| 57216| 58| 8726| 266773| 34%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 56708| 53| 8804| 270223| 33%|
+--------+-------------+--------+--------+---------+----------+------+
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
|QPL(IAA)| of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 30129| 34| 8345| 2224761| 54%|
|BW: 1G +-------------+--------+--------+---------+----------+------+
| | 4| 30317| 39| 8300| 2025220| 73%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 29615| 35| 8514| 2250122| 131%|
+--------+-------------+--------+--------+---------+----------+------+
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
| QPL(SW)| of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 93358| 41| 3064| 534588| 202%|
|BW: 1G +-------------+--------+--------+---------+----------+------+
| | 4| 47266| 52| 6067| 1392941| 402%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 33134| 45| 8706| 2433242| 580%|
+--------+-------------+--------+--------+---------+----------+------+
+--------+-------------+--------+--------+---------+----------+------|
| | The number |total |downtime|network |pages per | CPU |
| ZSTD | of channels |time(ms)|(ms) |bandwidth|second | Util |
| Comp | | | |(mbps) | | |
| +-------------+-----------------+---------+----------+------+
|Network | 2| 95750| 24| 1802| 477236| 202%|
|BW: 1G +-------------+--------+--------+---------+----------+------+
| | 4| 48907| 24| 3536| 1002142| 404%|
| +-------------+--------+--------+---------+----------+------+
| | 8| 25568| 32| 6783| 1696437| 800%|
+--------+-------------+--------+--------+---------+----------+------+
When network bandwidth resource is limited, the "page perf second" metric
decreases for none compression, the success rate of migration will reduce.
Comparison of QPL and ZSTD compression methods, QPL can save a lot of CPU
resources used for compression.
v2:
- add support for multifd compression accelerator
- add support for the QPL accelerator in the multifd
compression accelerator
- fixed the issue that QPL was compiled into the migration
module by default
v3:
- use Meson instead of pkg-config to resolve QPL build
dependency issue
- fix coding style
- fix a CI issue for get_multifd_ops function in multifd.c file
v4:
- patch based on commit: da96ad4a6a Merge tag 'hw-misc-20240215' of
https://github.com/philmd/qemu into staging
- remove the compression accelerator implementation patches, the patches
will be placed in the QAT accelerator implementation.
- introduce QPL as a new compression method
- add QPL compression documentation
- add QPL compression migration test
- fix zlib/zstd compression level issue
v5:
- patch based on v9.0.0-rc0 (c62d54d0a8)
- use pkgconfig to check libaccel-config, libaccel-config is already
in many distributions.
- initialize the IOV of the sender by the specific compression method
- refine the coding style
- remove the zlib/zstd compression level not working patch, the issue
has been solved
v6:
- rebase to commit id 248f6f62df, Merge tag 'pull-axp-20240504' of
https://gitlab.com/rth7680/qemu into staging.
- add qpl software path, if the hardware path(IAA) is unavailable, the
qpl will fall back to software path automatically.
- add pkgconfig to check qpl, qpl version 1.5 already supports pkgconfig,
users can install the qpl library and qpl.pc file through source code.
- remove libaccel-config library detection, if there is no the library,
the qpl will automatically switch to the software path.
- use g_malloc0 instead of mmap to apply for memory.
- add the more introduction of IAA device management, including usage
permission, resource configuration, etc in qpl-compression.rst.
- modified unit test to use software path to complete testing when
hardware path is unavailable.
Yuan Liu (7):
docs/migration: add qpl compression feature
migration/multifd: put IOV initialization into compression method
configure: add --enable-qpl build option
migration/multifd: add qpl compression method
migration/multifd: implement initialization of qpl compression
migration/multifd: implement qpl compression and decompression
tests/migration-test: add qpl compression test
Yuan Liu (7):
docs/migration: add qpl compression feature
migration/multifd: put IOV initialization into compression method
configure: add --enable-qpl build option
migration/multifd: add qpl compression method
migration/multifd: implement initialization of qpl compression
migration/multifd: implement qpl compression and decompression
tests/migration-test: add qpl compression test
docs/devel/migration/features.rst | 1 +
docs/devel/migration/qpl-compression.rst | 262 +++++++++++
hw/core/qdev-properties-system.c | 2 +-
meson.build | 8 +
meson_options.txt | 2 +
migration/meson.build | 1 +
migration/multifd-qpl.c | 566 +++++++++++++++++++++++
migration/multifd-zlib.c | 7 +
migration/multifd-zstd.c | 8 +-
migration/multifd.c | 22 +-
migration/multifd.h | 1 +
qapi/migration.json | 7 +-
scripts/meson-buildoptions.sh | 3 +
tests/qtest/migration-test.c | 24 +
14 files changed, 901 insertions(+), 13 deletions(-)
create mode 100644 docs/devel/migration/qpl-compression.rst
create mode 100644 migration/multifd-qpl.c
--
2.39.3