Re: sys_recvmmsg: wire up or not?
On Tue, 2010-01-19 at 16:21 +0900, Paul Mundt wrote: IE. I'd rather have them all duplicated into real syscalls than some of them only in socketcall and some on both since that will make any kind of userspace transition even more hellish. Presumably you're going to have to support both given that binaries with both ABIs are going to be left around for the forseeable future. We started out with socketcall on sh64 with the initial ABI and then transitioned over to broken out direct system calls. While having both is a bit inconsistent, it's not really something that can be avoided until all of the old binaries go away. There are certainly enough architectures today that provide both that you shouldn't really run in to any nasty surprises at least. I agree, my point was more like I'd rather not add the syscall for recvmmsg only right now, and others later, and instead of an all-or-nothing approach, ie, add all the syscalls at once (while keeping the socketcall around of course). That would make glibc work easier not having to track syscall availability on a per-syscall basis etc... Cheers, Ben. 32-bit SH only uses socketcall at the moment, but I'm also inclined to add in the broken out versions and start migrating glibc over. Unfortunately there are not a lot of good options for the syscall checker with things like this however, given that some platforms will want one or the other or both ;-) -- To unsubscribe from this list: send the line unsubscribe linux-m68k in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: sys_recvmmsg: wire up or not?
On Thu, Jan 14, 2010 at 05:59:39PM +1100, Benjamin Herrenschmidt wrote: Oh I definitely agree that a direct syscall is better, and I wonder in fact if I should add new syscalls in addition to socketcall for powerpc, for glibc to do a slow migration :-) I was just wondering about the inconsistency for archs like us who have socketcall today, to also have to define the syscall ... On ARM, we used to use socketcall exclusively. We've since added all the direct socket and IPC calls to our syscall table as part of the big EABI shakeup. They certainly get used on EABI, whereas OABI has a choice. They were made available in two stages - first the numbers were reserved and the calls were added to the call table. A few years later, we exposed the syscall numbers in unistd.h. It's now been almost 4 years since this was done, and there have been no bug reports. -- Russell King Linux kernel2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: -- To unsubscribe from this list: send the line unsubscribe linux-m68k in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: sys_recvmmsg: wire up or not?
On Thu, 2010-01-14 at 09:33 +, Russell King wrote: On ARM, we used to use socketcall exclusively. We've since added all the direct socket and IPC calls to our syscall table as part of the big EABI shakeup. They certainly get used on EABI, whereas OABI has a choice. They were made available in two stages - first the numbers were reserved and the calls were added to the call table. A few years later, we exposed the syscall numbers in unistd.h. It's now been almost 4 years since this was done, and there have been no bug reports. Agreed. It's definitely a switch we should do on powerpc. I'll look into it after LCA. Cheers, Ben. -- To unsubscribe from this list: send the line unsubscribe linux-m68k in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: sys_recvmmsg: wire up or not?
From: Benjamin Herrenschmidt b...@kernel.crashing.org Date: Thu, 14 Jan 2010 15:20:33 +1100 Anything happening here ? We're getting that warning on ppc too despite the fact that we use socketcall like x86... Should checksyscall be made smarter or the syscall just removed from x86 ? :-) I think it's better to trap directly to the system call rather than going through yet another demultiplexer. I severely regretted using sys_socketcall initially on sparc32 because it added a few microseconds to socket syscall latency (cpus back then were slow :-) -- To unsubscribe from this list: send the line unsubscribe linux-m68k in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: sys_recvmmsg: wire up or not?
On Wed, 2010-01-13 at 20:28 -0800, David Miller wrote: Anything happening here ? We're getting that warning on ppc too despite the fact that we use socketcall like x86... Should checksyscall be made smarter or the syscall just removed from x86 ? :-) I think it's better to trap directly to the system call rather than going through yet another demultiplexer. I severely regretted using sys_socketcall initially on sparc32 because it added a few microseconds to socket syscall latency (cpus back then were slow :-) Oh I definitely agree that a direct syscall is better, and I wonder in fact if I should add new syscalls in addition to socketcall for powerpc, for glibc to do a slow migration :-) I was just wondering about the inconsistency for archs like us who have socketcall today, to also have to define the syscall ... IE. I'd rather have them all duplicated into real syscalls than some of them only in socketcall and some on both since that will make any kind of userspace transition even more hellish. Cheers, Ben. -- To unsubscribe from this list: send the line unsubscribe linux-m68k in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: sys_recvmmsg: wire up or not?
On Saturday 26 December 2009, Geert Uytterhoeven wrote: stdin:1523:2: warning: #warning syscall recvmmsg not implemented so I started to wire up sys_recvmmsg. Then I noticed it's already accessible, through sys_socketcall, as m68k defines __ARCH_WANT_SYS_SOCKETCALL. So I guess this is a false positive? Yes. Surprisingly, several architectures have both defined __ARCH_WANT_SYS_SOCKETCALL and wired up sys_recvmmsg. Is this intentional? It's also rather inconsistent with the last socket call that was added, sys_accept4. Some architectures that normally define socket calls (parisc, sh) are missing both accept4 and recvmmsg, while others that don't have recvmsg now get recvmmsg. In particular, i386 has recvmmsg now, which caused the warning that you saw. I guess that one should be removed, and maybe we need a better logic for determining which syscalls you actually want. Deriving it from asm-generic/unistd.h instead of arch/x86/include/asm/unistd_32.h is probably better, but would still give the wrong answer for multiplexed system calls like socketcall or ipc on existing architectures. Arnd -- To unsubscribe from this list: send the line unsubscribe linux-m68k in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
