On Fri, Feb 02, 2024 at 04:49:47PM +0000, Al Viro wrote: > > +folks from `./scripts/get_maintainer.pl -f arch/arm64/kernel/ptrace.c` > > > > Trying to follow the macros to see where "n" comes from is a maze of > > twisty little passages, all alike. Hopefully someone from the ARM > > world can help tell if the value of 17474 for n here is correct or if > > something is wonky. > > It might be interesting to have it print the return value of __regset_get() > in those cases; if *that* is huge, we really have a problem. If it ends up > small enough to fit into few pages, OTOH... > > SVE_VQ_MAX is defined as 255; is that really in units of 128 bits? IOW, > do we really expect to support 32Kbit registers? That would drive the > size into that range, all right, but it would really suck on context > switches. > > I could be misreading it, though - the macros in there are not easy to > follow and I've never dealt with SVE before, so take the above with > a cartload of salt. Worse - it's SVE_VQ_MAX is 512; sorry about the confusion. OK, that would certainly explain the size (header + 32 registers, each up to 512 * 16 bytes), but... ouch.