user/sven/linux.git/arch/x86/kernel/syscall_table_32.S, branch v3.2.70

Cross Memory Attach

2011-11-01T00:30:44Z

The basic idea behind cross memory attach is to allow MPI programs doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. The following patch attempts to achieve this by allowing a destination process, given an address and size from a source process, to copy memory directly from the source process into its own address space via a system call. There is also a symmetrical ability to copy from the current process's address space into a destination process's address space. - Use of /proc/pid/mem has been considered, but there are issues with using it: - Does not allow for specifying iovecs for both src and dest, assuming preadv or pwritev was implemented either the area read from or written to would need to be contiguous. - Currently mem_read allows only processes who are currently ptrace'ing the target and are still able to ptrace the target to read from the target. This check could possibly be moved to the open call, but its not clear exactly what race this restriction is stopping (reason appears to have been lost) - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix domain socket is a bit ugly from a userspace point of view, especially when you may have hundreds if not (eventually) thousands of processes that all need to do this with each other - Doesn't allow for some future use of the interface we would like to consider adding in the future (see below) - Interestingly reading from /proc/pid/mem currently actually involves two copies! (But this could be fixed pretty easily) As mentioned previously use of vmsplice instead was considered, but has problems. Since you need the reader and writer working co-operatively if the pipe is not drained then you block. Which requires some wrapping to do non blocking on the send side or polling on the receive. In all to all communication it requires ordering otherwise you can deadlock. And in the example of many MPI tasks writing to one MPI task vmsplice serialises the copying. There are some cases of MPI collectives where even a single copy interface does not get us the performance gain we could. For example in an MPI_Reduce rather than copy the data from the source we would like to instead use it directly in a mathops (say the reduce is doing a sum) as this would save us doing a copy. We don't need to keep a copy of the data from the source. I haven't implemented this, but I think this interface could in the future do all this through the use of the flags - eg could specify the math operation and type and the kernel rather than just copying the data would apply the specified operation between the source and destination and store it in the destination. Although we don't have a "second user" of the interface (though I've had some nibbles from people who may be interested in using it for intra process messaging which is not MPI). This interface is something which hardware vendors are already doing for their custom drivers to implement fast local communication. And so in addition to this being useful for OpenMPI it would mean the driver maintainers don't have to fix things up when the mm changes. There was some discussion about how much faster a true zero copy would go. Here's a link back to the email with some testing I did on that: http://marc.info/?l=linux-mm&m=130105930902915&w=2 There is a basic man page for the proposed interface here: http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt This has been implemented for x86 and powerpc, other architecture should mainly (I think) just need to add syscall numbers for the process_vm_readv and process_vm_writev. There are 32 bit compatibility versions for 64-bit kernels. For arch maintainers there are some simple tests to be able to quickly verify that the syscalls are working correctly here: http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgz Signed-off-by: Chris Yeoh Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Gleixner Cc: Arnd Bergmann Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: David Howells Cc: James Morris Cc: Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

All Arch: remove linkage for sys_nfsservctl system call

2011-08-26T22:09:58Z

The nfsservctl system call is now gone, so we should remove all linkage for it. Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields Signed-off-by: Linus Torvalds

ns: Wire up the setns system call

2011-05-28T17:48:39Z

32bit and 64bit on x86 are tested and working. The rest I have looked at closely and I can't find any problems. setns is an easy system call to wire up. It just takes two ints so I don't expect any weird architecture porting problems. While doing this I have noticed that we have some architectures that are very slow to get new system calls. cris seems to be the slowest where the last system calls wired up were preadv and pwritev. avr32 is weird in that recvmmsg was wired up but never declared in unistd.h. frv is behind with perf_event_open being the last syscall wired up. On h8300 the last system call wired up was epoll_wait. On m32r the last system call wired up was fallocate. mn10300 has recvmmsg as the last system call wired up. The rest seem to at least have syncfs wired up which was new in the 2.6.39. v2: Most of the architecture support added by Daniel Lezcano v3: ported to v2.6.36-rc4 by: Eric W. Biederman v4: Moved wiring up of the system call to another patch v5: ported to v2.6.39-rc6 v6: rebased onto parisc-next and net-next to avoid syscall conflicts. v7: ported to Linus's latest post 2.6.39 tree. > arch/blackfin/include/asm/unistd.h | 3 ++- > arch/blackfin/mach-common/entry.S | 1 + Acked-by: Mike Frysinger Oh - ia64 wiring looks good. Acked-by: Tony Luck Signed-off-by: Eric W. Biederman Signed-off-by: Linus Torvalds

net: Add sendmmsg socket system call

2011-05-05T18:10:14Z

This patch adds a multiple message send syscall and is the send version of the existing recvmmsg syscall. This is heavily based on the patch by Arnaldo that added recvmmsg. I wrote a microbenchmark to test the performance gains of using this new syscall: http://ozlabs.org/~anton/junkcode/sendmmsg_test.c The test was run on a ppc64 box with a 10 Gbit network card. The benchmark can send both UDP and RAW ethernet packets. 64B UDP batch pkts/sec 1 804570 2 872800 (+ 8 %) 4 916556 (+14 %) 8 939712 (+17 %) 16 952688 (+18 %) 32 956448 (+19 %) 64 964800 (+20 %) 64B raw socket batch pkts/sec 1 1201449 2 1350028 (+12 %) 4 1461416 (+22 %) 8 1513080 (+26 %) 16 1541216 (+28 %) 32 1553440 (+29 %) 64 1557888 (+30 %) We see a 20% improvement in throughput on UDP send and 30% on raw socket send. [ Add sparc syscall entries. -DaveM ] Signed-off-by: Anton Blanchard Signed-off-by: David S. Miller

introduce sys_syncfs to sync a single file system

2011-03-21T04:40:29Z

It is frequently useful to sync a single file system, instead of all mounted file systems via sync(2): - On machines with many mounts, it is not at all uncommon for some of them to hang (e.g. unresponsive NFS server). sync(2) will get stuck on those and may never get to the one you do care about (e.g., /). - Some applications write lots of data to the file system and then want to make sure it is flushed to disk. Calling fsync(2) on each file introduces unnecessary ordering constraints that result in a large amount of sub-optimal writeback/flush/commit behavior by the file system. There are currently two ways (that I know of) to sync a single super_block: - BLKFLSBUF ioctl on the block device: That also invalidates the bdev mapping, which isn't usually desirable, and doesn't work for non-block file systems. - 'mount -o remount,rw' will call sync_filesystem as an artifact of the current implemention. Relying on this little-known side effect for something like data safety sounds foolish. Both of these approaches require root privileges, which some applications do not have (nor should they need?) given that sync(2) is an unprivileged operation. This patch introduces a new system call syncfs(2) that takes an fd and syncs only the file system it references. Maybe someday we can $ sync /some/path and not get sync: ignoring all arguments The syscall is motivated by comments by Al and Christoph at the last LSF. syncfs(2) seems like an appropriate name given statfs(2). A similar ioctl was also proposed a while back, see http://marc.info/?l=linux-fsdevel&m=127970513829285&w=2 Signed-off-by: Sage Weil Signed-off-by: Al Viro

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-03-16T01:53:35Z

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (62 commits) posix-clocks: Check write permissions in posix syscalls hrtimer: Remove empty hrtimer_init_hres_timer() hrtimer: Update hrtimer->state documentation hrtimer: Update base[CLOCK_BOOTTIME].offset correctly timers: Export CLOCK_BOOTTIME via the posix timers interface timers: Add CLOCK_BOOTTIME hrtimer base time: Extend get_xtime_and_monotonic_offset() to also return sleep time: Introduce get_monotonic_boottime and ktime_get_boottime hrtimers: extend hrtimer base code to handle more then 2 clockids ntp: Remove redundant and incorrect parameter check mn10300: Switch do_timer() to xtimer_update() posix clocks: Introduce dynamic clocks posix-timers: Cleanup namespace posix-timers: Add support for fd based clocks x86: Add clock_adjtime for x86 posix-timers: Introduce a syscall for clock tuning. time: Splitout compat timex accessors ntp: Add ADJ_SETOFFSET mode bit time: Introduce timekeeping_inject_offset posix-timer: Update comment ... Fix up new system-call-related conflicts in arch/x86/ia32/ia32entry.S arch/x86/include/asm/unistd_32.h arch/x86/include/asm/unistd_64.h arch/x86/kernel/syscall_table_32.S (name_to_handle_at()/open_by_handle_at() vs clock_adjtime()), and some due to movement of get_jiffies_64() in: kernel/time.c

x86: Add new syscalls for x86_32

2011-03-15T06:21:44Z

This patch adds new syscalls to x86_32 Signed-off-by: Aneesh Kumar K.V Signed-off-by: Al Viro

x86: Add clock_adjtime for x86

2011-02-02T14:28:19Z

This patch adds the clock_adjtime system call to the x86 architecture. Signed-off-by: Richard Cochran Acked-by: John Stultz LKML-Reference: <20110201134419.968905083@linutronix.de> Signed-off-by: Thomas Gleixner

x86: fix up system call numbering nit

2010-08-10T22:35:10Z

As pointed out by Jiri Slaby: when I resolved the the 32-bit x85 system call entry tables for prlimit (due to the conflict with fanotify), I forgot to add the numbering in comments that we do for every fifth entry. Reported-by: Jiri Slaby Signed-off-by: Linus Torvalds

Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux

2010-08-10T19:07:51Z

* 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux: unistd: add __NR_prlimit64 syscall numbers rlimits: implement prlimit64 syscall rlimits: switch more rlimit syscalls to do_prlimit rlimits: redo do_setrlimit to more generic do_prlimit rlimits: add rlimit64 structure rlimits: do security check under task_lock rlimits: allow setrlimit to non-current tasks rlimits: split sys_setrlimit rlimits: selinux, do rlimits changes under task_lock rlimits: make sure ->rlim_max never grows in sys_setrlimit rlimits: add task_struct to update_rlimit_cpu rlimits: security, add task_struct to setrlimit Fix up various system call number conflicts. We not only added fanotify system calls in the meantime, but asm-generic/unistd.h added a wait4 along with a range of reserved per-architecture system calls.