On 5/24/2010 2:53 PM, Arnd Bergmann wrote: > Note that the asm-generic version defines 244 numbers, while you have > a total of 313 numbers. You obviously need the extra arch specific > syscalls (e.g cmpxchg), so we need to reserve some space for those > in the generic header. All the other ones that are in your version but > not in the generic version are very likely not needed (unless I made > a mistake in the generic code). > I looked at the diff of the set of syscalls you provide and the ones we've been using. Specific questions: - How do you propose representing the architecture-specific syscalls? We have three "very special" syscalls that are negative numbers, which I won't worry about, since they'll be out of the normal numbering sequence. But we also have a few others (cmpxchg_baddr, raise_fpe, flush_cache) that we'll need a numbering location for. I see that you already have an empty block from 244 (today) to 1023; perhaps architectures should just use 1023 on down? I'll do this for now. - You renamed __NR__llseek to __NR_llseek, which of course seems pretty reasonable, but libc expects to see the former (both glibc and uclibc). Is it worth requiring non-standard libc code? I may just add __NR__llseek as an alias in my unistd.h for now. - Are you planning to keep all the ifdef'ed syscalls going forward? Because honestly, I'd rather just enable __ARCH_WANT_SYSCALL_NO_AT, etc., and use the kernel implementations, since otherwise I'll have to go into both uclibc and glibc and add a bunch of extra Tilera-specific code and then try to push that up to their community, when really I just want to have the Tilera architecture userspace support be as generic as possible. The result seems positive overall; I'm certainly happy to dump, e.g., "nice" and "stime", since they have obvious userspace wrappers (and in fact libc is already geared up to use them if available). And a few other syscalls in the Tile list aren't even implemented but were just brought over from x86 "in case", like afs_syscall, putpmsg, and getpmsg, so I'm happy to abandon them as well. And "sysfs" is commented out of uclibc, and not present in glibc, so no big loss there. Other than that I think the set of supported syscalls will only change by a couple -- and more importantly, from my point of view, Tilera gets to stay automatically synced to any new syscalls added to Linux going forward. So this is good. I assume that folks are committing to not changing any of the existing numbers, ifdefs, etc. in asm-generic/unistd.h; if we're the only architecture using it, no one might notice until we did. :-) -- Chris Metcalf, Tilera Corp. http://www.tilera.com -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
