v3: - Rebase changes on top of master - Merge two patches per Fabiano Rosas's comment - Add versions into comments and documentations
v2: - Rebase changes on top of recent multifd code changes. - Use QATzip API 'qzMalloc' and 'qzFree' to allocate QAT buffers. - Remove parameter tuning and use QATzip's defaults for better performance. - Add parameter to enable QAT software fallback. v1: https://lists.nongnu.org/archive/html/qemu-devel/2023-12/msg03761.html * Performance We present updated performance results. For circumstantial reasons, v1 presented performance on a low-bandwidth (1Gbps) network. Here, we present updated results with a similar setup as before but with two main differences: 1. Our machines have a ~50Gbps connection, tested using 'iperf3'. 2. We had a bug in our memory allocation causing us to only use ~1/2 of the VM's RAM. Now we properly allocate and fill nearly all of the VM's RAM. Thus, the test setup is as follows: We perform multifd live migration over TCP using a VM with 64GB memory. We prepare the machine's memory by powering it on, allocating a large amount of memory (60GB) as a single buffer, and filling the buffer with the repeated contents of the Silesia corpus[0]. This is in lieu of a more realistic memory snapshot, which proved troublesome to acquire. We analyze CPU usage by averaging the output of 'top' every second during migration. This is admittedly imprecise, but we feel that it accurately portrays the different degrees of CPU usage of varying compression methods. We present the latency, throughput, and CPU usage results for all of the compression methods, with varying numbers of multifd threads (4, 8, and 16). [0] The Silesia corpus can be accessed here: https://sun.aei.polsl.pl//~sdeor/index.php?page=silesia ** Results 4 multifd threads: |---------------|---------------|----------------|---------|---------| |method |time(sec) |throughput(mbps)|send cpu%|recv cpu%| |---------------|---------------|----------------|---------|---------| |qatzip | 23.13 | 8749.94 |117.50 |186.49 | |---------------|---------------|----------------|---------|---------| |zlib |254.35 | 771.87 |388.20 |144.40 | |---------------|---------------|----------------|---------|---------| |zstd | 54.52 | 3442.59 |414.59 |149.77 | |---------------|---------------|----------------|---------|---------| |none | 12.45 |43739.60 |159.71 |204.96 | |---------------|---------------|----------------|---------|---------| 8 multifd threads: |---------------|---------------|----------------|---------|---------| |method |time(sec) |throughput(mbps)|send cpu%|recv cpu%| |---------------|---------------|----------------|---------|---------| |qatzip | 16.91 |12306.52 |186.37 |391.84 | |---------------|---------------|----------------|---------|---------| |zlib |130.11 | 1508.89 |753.86 |289.35 | |---------------|---------------|----------------|---------|---------| |zstd | 27.57 | 6823.23 |786.83 |303.80 | |---------------|---------------|----------------|---------|---------| |none | 11.82 |46072.63 |163.74 |238.56 | |---------------|---------------|----------------|---------|---------| 16 multifd threads: |---------------|---------------|----------------|---------|---------| |method |time(sec) |throughput(mbps)|send cpu%|recv cpu%| |---------------|---------------|----------------|---------|---------| |qatzip |18.64 |11044.52 | 573.61 |437.65 | |---------------|---------------|----------------|---------|---------| |zlib |66.43 | 2955.79 |1469.68 |567.47 | |---------------|---------------|----------------|---------|---------| |zstd |14.17 |13290.66 |1504.08 |615.33 | |---------------|---------------|----------------|---------|---------| |none |16.82 |32363.26 | 180.74 |217.17 | |---------------|---------------|----------------|---------|---------| ** Observations - In general, not using compression outperforms using compression in a non-network-bound environment. - 'qatzip' outperforms other compression workers with 4 and 8 workers, achieving a ~91% latency reduction over 'zlib' with 4 workers, and a ~58% latency reduction over 'zstd' with 4 workers. - 'qatzip' maintains comparable performance with 'zstd' at 16 workers, showing a ~32% increase in latency. This performance difference becomes more noticeable with more workers, as CPU compression is highly parallelizable. - 'qatzip' compression uses considerably less CPU than other compression methods. At 8 workers, 'qatzip' demonstrates a ~75% reduction in compression CPU usage compared to 'zstd' and 'zlib'. - 'qatzip' decompression CPU usage is less impressive, and is even slightly worse than 'zstd' and 'zlib' CPU usage at 4 and 16 workers. Bryan Zhang (4): meson: Introduce 'qatzip' feature to the build system migration: Add migration parameters for QATzip migration: Introduce 'qatzip' compression method tests/migration: Add integration test for 'qatzip' compression method hw/core/qdev-properties-system.c | 6 +- meson.build | 10 + meson_options.txt | 2 + migration/meson.build | 1 + migration/migration-hmp-cmds.c | 8 + migration/multifd-qatzip.c | 382 +++++++++++++++++++++++++++++++ migration/multifd.h | 1 + migration/options.c | 57 +++++ migration/options.h | 2 + qapi/migration.json | 38 +++ scripts/meson-buildoptions.sh | 6 + tests/qtest/meson.build | 4 + tests/qtest/migration-test.c | 35 +++ 13 files changed, 551 insertions(+), 1 deletion(-) create mode 100644 migration/multifd-qatzip.c -- Yichen Wang
