diff --git a/doc-Update-multi-thread-compression-doc.patch b/doc-Update-multi-thread-compression-doc.patch new file mode 100644 index 0000000..33ef835 --- /dev/null +++ b/doc-Update-multi-thread-compression-doc.patch @@ -0,0 +1,85 @@ +From 642df85795097017e9370a9721f702cbec50c173 Mon Sep 17 00:00:00 2001 +From: Zeyu Jin +Date: Sat, 30 Jan 2021 16:36:47 +0800 +Subject: [PATCH] doc: Update multi-thread compression doc + +Modify the doc to fit the previous changes. + +Signed-off-by: Zeyu Jin +Signed-off-by: Ying Fang +--- + docs/multi-thread-compression.txt | 31 ++++++++++++++++++------------- + 1 file changed, 18 insertions(+), 13 deletions(-) + +diff --git a/docs/multi-thread-compression.txt b/docs/multi-thread-compression.txt +index bb88c6bdf1..d429963cb0 100644 +--- a/docs/multi-thread-compression.txt ++++ b/docs/multi-thread-compression.txt +@@ -33,14 +33,15 @@ thread compression can be used to accelerate the compression process. + + The decompression speed of Zlib is at least 4 times as quick as + compression, if the source and destination CPU have equal speed, +-keeping the compression thread count 4 times the decompression +-thread count can avoid resource waste. ++and you choose Zlib as compression method, keeping the compression ++thread count 4 times the decompression thread count can avoid resource waste. + + Compression level can be used to control the compression speed and the +-compression ratio. High compression ratio will take more time, level 0 +-stands for no compression, level 1 stands for the best compression +-speed, and level 9 stands for the best compression ratio. Users can +-select a level number between 0 and 9. ++compression ratio. High compression ratio will take more time, ++level 1 stands for the best compression speed, and higher level means higher ++compression ration. For Zlib, users can select a level number between 0 and 9, ++where level 0 stands for no compression. For Zstd, users can select a ++level number between 1 and 22. + + + When to use the multiple thread compression in live migration +@@ -116,16 +117,19 @@ to support the multiple thread compression migration: + 2. Activate compression on the source: + {qemu} migrate_set_capability compress on + +-3. Set the compression thread count on source: ++3. Set the compression method: ++ {qemu} migrate_set_parameter compress_method zstd ++ ++4. Set the compression thread count on source: + {qemu} migrate_set_parameter compress_threads 12 + +-4. Set the compression level on the source: ++5. Set the compression level on the source: + {qemu} migrate_set_parameter compress_level 1 + +-5. Set the decompression thread count on destination: ++6. Set the decompression thread count on destination: + {qemu} migrate_set_parameter decompress_threads 3 + +-6. Start outgoing migration: ++7. Start outgoing migration: + {qemu} migrate -d tcp:destination.host:4444 + {qemu} info migrate + Capabilities: ... compress: on +@@ -136,6 +140,7 @@ The following are the default settings: + compress_threads: 8 + decompress_threads: 2 + compress_level: 1 (which means best speed) ++ compress_method: zlib + + So, only the first two steps are required to use the multiple + thread compression in migration. You can do more if the default +@@ -143,7 +148,7 @@ settings are not appropriate. + + TODO + ==== +-Some faster (de)compression method such as LZ4 and Quicklz can help +-to reduce the CPU consumption when doing (de)compression. If using +-these faster (de)compression method, less (de)compression threads ++Comparing to Zlib, Some faster (de)compression method such as LZ4 ++and Quicklz can help to reduce the CPU consumption when doing (de)compression. ++If using these faster (de)compression method, less (de)compression threads + are needed when doing the migration. +-- +2.27.0 +