Open mjp41 opened 1 year ago
OpenBSD does not support overcommit nor have any sort of OOM as linux has, instead the memory allocation will just fail.
How did it ever work on OpenBSD? Did it only work on 32-bit systems?
Originally, the pagemap was only 16MiB (i.e. in the paper). So at that point it could have worked reasonably. I am thinking we should drop OpenBSD from the CI?
IIRC, snmalloc1
also had a tree-based PageMap option... someone very keen on OpenBSD support could reinstate that? (It should be relatively straightforward as these things go?)
We currently have OpenBSD in CI, but the system is failing to initialise the pagemap.
I believe this is because the pagemap is very large, and OpenBSD does not support overcommit. I could not find a
MAP_NORESERVE
like flag that could be used.Given the current design, I do not see a way to support an OS that does not separate the concept of reserve and commit, either explicitly as in Windows, or implicitly as in Linux and FreeBSD.
I am raising this issue to track thoughts on this.
@nwf-msr, @davidchisnall, @devnexen