Re: [GIT PULL] Namespace file descriptors for 2.6.40
From: Ingo Molnar <hidden>
Date: 2011-05-25 13:18:05
Also in:
lkml
* Geert Uytterhoeven [off-list ref] wrote:
On Wed, May 25, 2011 at 14:47, Ingo Molnar [off-list ref] wrote:quoted
* Geert Uytterhoeven [off-list ref] wrote:quoted
quoted
But at least the primary, 'native' syscall table of every arch could be kept rather fresh via generic enumeration.So we can start all over at offset 501 (alpha just started using 500) with a unified, clean, and compressed list of syscalls? Or do we have some more other-os-compat syscalls around in this range?No, that would leave a big hole in the syscall table of most architectures.Sure, but we could (a) optimize for the case where the syscall number is larger than 500 and/or (b) drop support for syscall numbers smaller than 501, depending on a config option.
Dunno why there is so much desire to complicate and break well-working ABIs while we have a 14+ MLOC kernel with so much code in it that is in dire need to be improved! :-) Yes, we can reduce the syscall addition pain via the ARCH_SYSCALLS_BASE trick, but we should really forget about *removing* (or reordering) syscall numbers as the advantages are marginal at best while the disadvantages are huge. Messy syscall tables are irreversibly ingrained in tens of millions of systems and there's nothing we can do about that. We can improve the future shape of syscall tables and we can try not to make new mistakes, and that's a large enough job in itself ;-) Thanks, Ingo