Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[SPARK-21305][ML][MLLIB]Add options to disable multi-threading of native BLAS #18551

Closed
wants to merge 7 commits into from
Closed

[SPARK-21305][ML][MLLIB]Add options to disable multi-threading of native BLAS #18551

Show file tree
Hide file tree
Changes from 6 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
d0d94e1
disable multi-threading in spark-env.sh
Jul 6, 2017
adfa6f1
revise the doc
Jul 6, 2017
08e900b
revise the doc
Jul 6, 2017
7ef8b80
add link
Jul 6, 2017
a4d4f50
add OpenBlas multi-threading introduction
Jul 6, 2017
141d92d
add recommended setting for native blas link
Jul 11, 2017
e01a613
fix ml-guide.md
Jul 11, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions conf/spark-env.sh.template
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -61,3 +61,7 @@
# - SPARK_IDENT_STRING A string representing this instance of spark. (Default: $USER)
# - SPARK_NICENESS The scheduling priority for daemons. (Default: 0)
# - SPARK_NO_DAEMONIZE Run the proposed command in the foreground. It will not output a PID file.
# Options for native BLAS, like Intel MKL, OpenBLAS, and so on.
# You might get better performance to enable these options if using native BLAS (see SPARK-21305).
# - MKL_NUM_THREADS=1 Disable multi-threading of Intel MKL
# - OPENBLAS_NUM_THREADS=1 Disable multi-threading of OpenBLAS
6 changes: 6 additions & 0 deletions docs/ml-guide.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -61,6 +61,12 @@ To configure `netlib-java` / Breeze to use system optimised binaries, include
project and read the [netlib-java](https://github.com/fommil/netlib-java) documentation for your
platform's additional installation instructions.

The most popular native BLAS such as [Intel MKL](https://software.intel.com/en-us/mkl), [OpenBLAS](http://www.openblas.net), are based on multi-threading, which will conflict with Spark.
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I would say "can use multiple threads in a single operation, which can conflict with Spark's execution model."


If using a native BLAS based on multi-threading, you might get better performance to set it to use single thread first ([SPARK-21305](https://issues.apache.org/jira/browse/SPARK-21305)).
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I might say, "Configuring these BLAS implementations to use a single thread for operations may actually improve performance (see ...). It is usually optimal to match this to the number of cores each Spark task is configured to use, which is 1 by default and typically left at 1."


Please reference the recommended settings for [Intel MKL](https://software.intel.com/en-us/articles/recommended-settings-for-calling-intel-mkl-routines-from-multi-threaded-applications) and [OpenBLAS](https://github.com/xianyi/OpenBLAS/wiki/faq#multi-threaded).
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Maybe: "Please refer to resources like the following to understand how to configure the number of threads these BLAS implementations use: ..."

Copy link
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done, thanks very much. @srowen


To use MLlib in Python, you will need [NumPy](http://www.numpy.org) version 1.4 or newer.

[^1]: To learn more about the benefits and background of system optimised natives, you may wish to
Expand Down