Message ID | 20220718161745.652970-1-foss+yocto@0leil.net |
---|---|
State | New |
Headers | show |
Series | [dunfell] ref-manual: Add XZ_THREADS and XZ_MEMLIMIT | expand |
Hi Quentin Thanks for the patch! On 7/18/22 18:17, Quentin Schulz wrote: > From: Richard Purdie <richard.purdie@linuxfoundation.org> > > XZ_THREADS and XZ_MEMLIMIT were introduced in dunfell. > > [RP improved an original patch from Paul] > Signed-off-by: Paul Eggleton <paul.eggleton@microsoft.com> > Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> > Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com> > --- > documentation/ref-manual/ref-variables.rst | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/documentation/ref-manual/ref-variables.rst b/documentation/ref-manual/ref-variables.rst > index 49e756cfb..c5facfa98 100644 > --- a/documentation/ref-manual/ref-variables.rst > +++ b/documentation/ref-manual/ref-variables.rst > @@ -8745,4 +8745,23 @@ system and gives an overview of their function and contents. > > The default value of ``XSERVER``, if not specified in the machine > configuration, is "xserver-xorg xf86-video-fbdev xf86-input-evdev". > - > + > + :term:`XZ_THREADS` > + Specifies the number of parallel threads that should be used when > + using xz compression. > + > + By default this scales with core count, but is never set less than 2 > + to ensure that multi-threaded mode is always used so that the output > + file contents are deterministic. Builds will work with a value of 1 > + but the output will differ compared to the output from the compression > + generated when more than one thread is used. > + > + On systems where many tasks run in parallel, setting a limit to this > + can be helpful in controlling system resource usage. > + > + :term:`XZ_MEMLIMIT` > + Specifies the maximum memory the xz compression should use as a percentage > + of system memory. If unconstrained the xz compressor can use large amounts of > + memory and become problematic with parallelism elsewhere in the build. > + "50%" has been found to be a good value. > + Reviewed-by: Michael Opdenacker <michael.opdenacker@bootlin.com> and merged into the "dunfell" branch. Thanks again! Michael.
diff --git a/documentation/ref-manual/ref-variables.rst b/documentation/ref-manual/ref-variables.rst index 49e756cfb..c5facfa98 100644 --- a/documentation/ref-manual/ref-variables.rst +++ b/documentation/ref-manual/ref-variables.rst @@ -8745,4 +8745,23 @@ system and gives an overview of their function and contents. The default value of ``XSERVER``, if not specified in the machine configuration, is "xserver-xorg xf86-video-fbdev xf86-input-evdev". - + + :term:`XZ_THREADS` + Specifies the number of parallel threads that should be used when + using xz compression. + + By default this scales with core count, but is never set less than 2 + to ensure that multi-threaded mode is always used so that the output + file contents are deterministic. Builds will work with a value of 1 + but the output will differ compared to the output from the compression + generated when more than one thread is used. + + On systems where many tasks run in parallel, setting a limit to this + can be helpful in controlling system resource usage. + + :term:`XZ_MEMLIMIT` + Specifies the maximum memory the xz compression should use as a percentage + of system memory. If unconstrained the xz compressor can use large amounts of + memory and become problematic with parallelism elsewhere in the build. + "50%" has been found to be a good value. +