On Tue, Jul 28, 2020 at 15:08:11 +0100, Daniel Berrange wrote:
On Tue, Jul 28, 2020 at 04:04:39PM +0200, Pavel Hrdina wrote:
On Tue, Jul 28, 2020 at 03:48:29PM +0200, Peter Krempa wrote:
On Thu, Jul 16, 2020 at 11:59:38 +0200, Pavel Hrdina wrote:
Signed-off-by: Pavel Hrdina <phrdina@redhat.com> --- build-aux/Makefile.in | 9 +++ .../Makefile.nonreentrant | 0 build-aux/meson.build | 30 +++++++++ build-aux/syntax-check.mk | 62 +++++++++---------- meson.build | 2 + 5 files changed, 72 insertions(+), 31 deletions(-) create mode 100644 build-aux/Makefile.in rename Makefile.nonreentrant => build-aux/Makefile.nonreentrant (100%) create mode 100644 build-aux/meson.build
[...]
+make_prog = find_program('make') + +# There is no way how to pass value to -j using run_target so let's use +# it without any value to run all tests in parallel. +run_target( + 'syntax-check', + command: [ + make_prog, '-C', meson.current_build_dir(), '-j', 'syntax-check', + ],
While I do run syntax check with unlimited '-j'. I don't think it's entirely cool to impose that on everybody. Specifically overcommiting the system is not cool. Since meson is automagically scaling can't we use the meson-detected cpu number here?
Unfortunately no, that was the first thing I was trying to figure out by going through meson code as well. It's not ideal I know.
Other options are to not use -j at all which is no-go or we can add some code to detect the available number of CPUs. But again it would not reflect the fact if user runs 'ninja -j N'.
In libosinfo we put "syntax-check" as part of the unit tests, rather than as a separate meson target. With that you don't need to pass -j to syntax-check, because other unit tests are running in parallel already, and chances are syntax-check will finish first even when serialized.
Unfortunately it's not even close. Serialized syntax-check: real 0m22.139s user 0m24.209s sys 0m6.788s test suite: real 0m4.833s user 0m12.408s sys 0m3.918s syntax-check with -j == ncpus: (24 thread box) real 0m2.099s user 0m28.558s sys 0m7.739s As said, I'm a big fan of -jncpus or -j. so I really want to keep it especially given the data above, but on the other hand I don't want to set the CI boxes on fire.