Hi, On 2023-10-19 13:44:20 -0400, Robert Haas wrote: > Twice now, I've had 'meson test' fail because it tried to start too > many copies of the server at the same time. In the server log, I get > the complaint about needing to raise SHMMNI. This is a macos machine, > with kern.sysv.shmmni=32.
Hm. Did you not run into simmilar issues with make check-world? I found the concurrency of that to be even more variable over a run. But perhaps there's something else wrong here? Perhaps we should deal with this in Cluster.pm to some degree? Controlling this from the level of meson (or make/prove for that matter) doesn't really work well, because different tests start differently many postgres instances. How many cores does your machine have? I've run the tests in a loop on my m1 mac mini in the past without running into this issue. It has "only" 8 cores though, whereas I infer, from you mentioning -j8, that you have more cores? > The obvious fix to this is to just tell 'meson test' how many processes I'd > like it to run. I thought maybe I could just do 'meson -j8 test' but that > does not work, because the option is --num-processes and has no short > version. Even typing -j8 every time would be kind of annoying; typing > --num-processes 8 every time is ridiculously verbose. I've also wondered why there's no support for -j, maybe we should open an issue... > My next thought was that there ought to be some environmental variable > that I could set to control this behavior. But I can't find a list of > environment variables that affect meson behavior anywhere. I guess the > authors don't believe in environment variable as a control mechanism. They indeed do not like them - but there is one in this case: MESON_TESTTHREADS There's even documentation for it: https://mesonbuild.com/Unit-tests.html#parallelism > Or, at the risk of sounding a bit testy, maybe their documentation > just isn't quite up to par. It's not that hard to find lists of > options for particular subcommands, either from the tool itself or on > the web site. But unlike git, where you can do something like 'man > git-checkout' and actually get more information than the command help > itself provides, there are no man pages for the main subcommands, and > I can't really find any good documentation on the web site either. > Knowing that a certain subcommand has a flag called > --pkgconfig.relocatable or that some other command has a flag called > --cross-file CROSS_FILE whose argument is, and I quote, a "File > describing cross compilation environment," is not good enough. I agree that meson's documentation is of, let's say, varying quality. But https://mesonbuild.com/Commands.html#test does link to https://mesonbuild.com/Unit-tests.html which in turn has the bit about MESON_TESTTHREADS I do agree that it'd be nice if the online docs were converted to command specific manpages... Greetings, Andres Freund
