On Fri, 2025-06-27 at 14:31 +0200, wrotycz wrote: > > Of course none of this is very relevant to the issue under > > discussion. > > I'm lost now.
What I'm trying to say is that the exact number of jobs used as a default is not really that important. I have no problem saying that the default number (should we decide to use it) would be 1 * ncpu. I would not say, though, that it's completely obvious that this value is always the best in every situation, which was your original claim. The important, difficult, and time-consuming thing is to decide (a) whether to make the change in the first place, and, if so, (b) what the new behavior of the various options should be. There are two issues here: one is that "-j" has a poor choice for default behavior because it can cause hundreds of jobs to be spawned very quickly and bring the system to a standstill, which is bad. The other is that it's difficult to set a generic value for "-j" (say in a MAKEFLAGS environment variable, or even in the makefile itself) that works across a variety of systems with different CPU counts. Is it sufficient to solve the second issue without addressing the first? If so you could imagine supporting more complex values for "-j"; for example, "-jn" means "number of CPUs", while "-j2n" means "twice the number of CPUs", or something like that. This is a backward-compatible change so it's not so controversial. If you really want to address the first issue, the default behavior of "-j" with no argument, then that's a change to long-standing behavior so needs to be considered carefully.
