21 May, 2010

1 commit

  • This patch modifies the fs/timerfd.c to use the newly created
    wait_event_interruptible_locked_irq() macro. This replaces an open
    code implementation with a single macro call.

    Signed-off-by: Michal Nazarewicz
    Cc: Kyungmin Park
    Cc: Marek Szyprowski
    Cc: Alexander Viro
    Cc: Thomas Gleixner
    Cc: Roland Dreier
    Cc: Tejun Heo
    Cc: Christoph Lameter
    Cc: Davide Libenzi
    Signed-off-by: Greg Kroah-Hartman

    Michal Nazarewicz
     

30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

23 Dec, 2009

1 commit

  • It seems a couple places such as arch/ia64/kernel/perfmon.c and
    drivers/infiniband/core/uverbs_main.c could use anon_inode_getfile()
    instead of a private pseudo-fs + alloc_file(), if only there were a way
    to get a read-only file. So provide this by having anon_inode_getfile()
    create a read-only file if we pass O_RDONLY in flags.

    Signed-off-by: Roland Dreier
    Signed-off-by: Al Viro

    Roland Dreier
     

19 Feb, 2009

1 commit

  • As requested by Michael, add a missing check for valid flags in
    timerfd_settime(), and make it return EINVAL in case some extra bits are
    set.

    Michael said:
    If this is to be any use to userland apps that want to check flag
    support (perhaps it is too late already), then the sooner we get it
    into the kernel the better: 2.6.29 would be good; earlier stables as
    well would be even better.

    [akpm@linux-foundation.org: remove unused TFD_FLAGS_SET]
    Acked-by: Michael Kerrisk
    Signed-off-by: Davide Libenzi
    Cc: [2.6.27.x, 2.6.28.x]
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davide Libenzi
     

14 Jan, 2009

2 commits


06 Sep, 2008

1 commit


25 Jul, 2008

4 commits

  • This patch adds test that ensure the boundary conditions for the various
    constants introduced in the previous patches is met. No code is generated.

    [akpm@linux-foundation.org: fix alpha]
    Signed-off-by: Ulrich Drepper
    Acked-by: Davide Libenzi
    Cc: Michael Kerrisk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ulrich Drepper
     
  • This patch adds support for the TFD_NONBLOCK flag to timerfd_create. The
    additional changes needed are minimal.

    The following test must be adjusted for architectures other than x86 and
    x86-64 and in case the syscall numbers changed.

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #include
    #include
    #include
    #include
    #include

    #ifndef __NR_timerfd_create
    # ifdef __x86_64__
    # define __NR_timerfd_create 283
    # elif defined __i386__
    # define __NR_timerfd_create 322
    # else
    # error "need __NR_timerfd_create"
    # endif
    #endif

    #define TFD_NONBLOCK O_NONBLOCK

    int
    main (void)
    {
    int fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, 0);
    if (fd == -1)
    {
    puts ("timerfd_create(0) failed");
    return 1;
    }
    int fl = fcntl (fd, F_GETFL);
    if (fl == -1)
    {
    puts ("fcntl failed");
    return 1;
    }
    if (fl & O_NONBLOCK)
    {
    puts ("timerfd_create(0) set non-blocking mode");
    return 1;
    }
    close (fd);

    fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, TFD_NONBLOCK);
    if (fd == -1)
    {
    puts ("timerfd_create(TFD_NONBLOCK) failed");
    return 1;
    }
    fl = fcntl (fd, F_GETFL);
    if (fl == -1)
    {
    puts ("fcntl failed");
    return 1;
    }
    if ((fl & O_NONBLOCK) == 0)
    {
    puts ("timerfd_create(TFD_NONBLOCK) set non-blocking mode");
    return 1;
    }
    close (fd);

    puts ("OK");

    return 0;
    }
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    Signed-off-by: Ulrich Drepper
    Acked-by: Davide Libenzi
    Cc: Michael Kerrisk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ulrich Drepper
     
  • The timerfd_create syscall already has a flags parameter. It just is
    unused so far. This patch changes this by introducing the TFD_CLOEXEC
    flag to set the close-on-exec flag for the returned file descriptor.

    A new name TFD_CLOEXEC is introduced which in this implementation must
    have the same value as O_CLOEXEC.

    The following test must be adjusted for architectures other than x86 and
    x86-64 and in case the syscall numbers changed.

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #include
    #include
    #include
    #include
    #include

    #ifndef __NR_timerfd_create
    # ifdef __x86_64__
    # define __NR_timerfd_create 283
    # elif defined __i386__
    # define __NR_timerfd_create 322
    # else
    # error "need __NR_timerfd_create"
    # endif
    #endif

    #define TFD_CLOEXEC O_CLOEXEC

    int
    main (void)
    {
    int fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, 0);
    if (fd == -1)
    {
    puts ("timerfd_create(0) failed");
    return 1;
    }
    int coe = fcntl (fd, F_GETFD);
    if (coe == -1)
    {
    puts ("fcntl failed");
    return 1;
    }
    if (coe & FD_CLOEXEC)
    {
    puts ("timerfd_create(0) set close-on-exec flag");
    return 1;
    }
    close (fd);

    fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, TFD_CLOEXEC);
    if (fd == -1)
    {
    puts ("timerfd_create(TFD_CLOEXEC) failed");
    return 1;
    }
    coe = fcntl (fd, F_GETFD);
    if (coe == -1)
    {
    puts ("fcntl failed");
    return 1;
    }
    if ((coe & FD_CLOEXEC) == 0)
    {
    puts ("timerfd_create(TFD_CLOEXEC) set close-on-exec flag");
    return 1;
    }
    close (fd);

    puts ("OK");

    return 0;
    }
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    Signed-off-by: Ulrich Drepper
    Acked-by: Davide Libenzi
    Cc: Michael Kerrisk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ulrich Drepper
     
  • This patch just extends the anon_inode_getfd interface to take an additional
    parameter with a flag value. The flag value is passed on to
    get_unused_fd_flags in anticipation for a use with the O_CLOEXEC flag.

    No actual semantic changes here, the changed callers all pass 0 for now.

    [akpm@linux-foundation.org: KVM fix]
    Signed-off-by: Ulrich Drepper
    Acked-by: Davide Libenzi
    Cc: Michael Kerrisk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ulrich Drepper
     

02 May, 2008

1 commit

  • a) none of the callers even looks at inode or file returned by anon_inode_getfd()
    b) any caller that would try to look at those would be racy, since by the time
    it returns we might have raced with close() from another thread and that
    file would be pining for fjords.

    Signed-off-by: Al Viro

    Al Viro
     

29 Apr, 2008

1 commit


06 Feb, 2008

1 commit

  • This is the new timerfd API as it is implemented by the following patch:

    int timerfd_create(int clockid, int flags);
    int timerfd_settime(int ufd, int flags,
    const struct itimerspec *utmr,
    struct itimerspec *otmr);
    int timerfd_gettime(int ufd, struct itimerspec *otmr);

    The timerfd_create() API creates an un-programmed timerfd fd. The "clockid"
    parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME.

    The timerfd_settime() API give new settings by the timerfd fd, by optionally
    retrieving the previous expiration time (in case the "otmr" parameter is not
    NULL).

    The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit
    is set in the "flags" parameter. Otherwise it's a relative time.

    The timerfd_gettime() API returns the next expiration time of the timer, or
    {0, 0} if the timerfd has not been set yet.

    Like the previous timerfd API implementation, read(2) and poll(2) are
    supported (with the same interface). Here's a simple test program I used to
    exercise the new timerfd APIs:

    http://www.xmailserver.org/timerfd-test2.c

    [akpm@linux-foundation.org: coding-style cleanups]
    [akpm@linux-foundation.org: fix ia64 build]
    [akpm@linux-foundation.org: fix m68k build]
    [akpm@linux-foundation.org: fix mips build]
    [akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds]
    [heiko.carstens@de.ibm.com: fix s390]
    [akpm@linux-foundation.org: fix powerpc build]
    [akpm@linux-foundation.org: fix sparc64 more]
    Signed-off-by: Davide Libenzi
    Cc: Michael Kerrisk
    Cc: Thomas Gleixner
    Cc: Davide Libenzi
    Cc: Michael Kerrisk
    Cc: Martin Schwidefsky
    Signed-off-by: Heiko Carstens
    Cc: Michael Kerrisk
    Cc: Davide Libenzi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davide Libenzi
     

27 Jul, 2007

1 commit

  • Davi fixed a missing cast in the __put_user(), that was making timerfd
    return a single byte instead of the full value.

    Talking with Michael about the timerfd man page, we think it'd be better to
    use a u64 for the returned value, to align it with the eventfd
    implementation.

    This is an ABI change. The timerfd code is new in 2.6.22 and if we merge this
    into 2.6.23 then we should also merge it into 2.6.22.x. That will leave a few
    early 2.6.22 kernels out in the wild which might misbehave when a future
    timerfd-enabled glibc is run on them.

    mtk says: The difference would be that read() will only return 4 bytes, while
    the application will expect 8. If the application is checking the size of
    returned value, as it should, then it will be able to detect the problem (it
    could even be sophisticated enough to know that if this is a 4-byte return,
    then it is running on an old 2.6.22 kernel). If the application is not
    checking the return from read(), then its 8-byte buffer will not be filled --
    the contents of the last 4 bytes will be undefined, so the u64 value as a
    whole will be junk.

    Signed-off-by: Davide Libenzi
    Cc: Michael Kerrisk
    Cc: Davi Arnaut
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davide Libenzi
     

19 May, 2007

1 commit

  • The timerfd was using the unlocked waitqueue operations, but it was
    using a different lock, so poll_wait() would race with it.

    This makes timerfd directly use the waitqueue lock.

    Signed-off-by: Davide Libenzi
    Signed-off-by: Linus Torvalds

    Davide Libenzi
     

11 May, 2007

1 commit

  • This patch introduces a new system call for timers events delivered though
    file descriptors. This allows timer event to be used with standard POSIX
    poll(2), select(2) and read(2). As a consequence of supporting the Linux
    f_op->poll subsystem, they can be used with epoll(2) too.

    The system call is defined as:

    int timerfd(int ufd, int clockid, int flags, const struct itimerspec *utmr);

    The "ufd" parameter allows for re-use (re-programming) of an existing timerfd
    w/out going through the close/open cycle (same as signalfd). If "ufd" is -1,
    s new file descriptor will be created, otherwise the existing "ufd" will be
    re-programmed.

    The "clockid" parameter is either CLOCK_MONOTONIC or CLOCK_REALTIME. The time
    specified in the "utmr->it_value" parameter is the expiry time for the timer.

    If the TFD_TIMER_ABSTIME flag is set in "flags", this is an absolute time,
    otherwise it's a relative time.

    If the time specified in the "utmr->it_interval" is not zero (.tv_sec == 0,
    tv_nsec == 0), this is the period at which the following ticks should be
    generated.

    The "utmr->it_interval" should be set to zero if only one tick is requested.
    Setting the "utmr->it_value" to zero will disable the timer, or will create a
    timerfd without the timer enabled.

    The function returns the new (or same, in case "ufd" is a valid timerfd
    descriptor) file, or -1 in case of error.

    As stated before, the timerfd file descriptor supports poll(2), select(2) and
    epoll(2). When a timer event happened on the timerfd, a POLLIN mask will be
    returned.

    The read(2) call can be used, and it will return a u32 variable holding the
    number of "ticks" that happened on the interface since the last call to
    read(2). The read(2) call supportes the O_NONBLOCK flag too, and EAGAIN will
    be returned if no ticks happened.

    A quick test program, shows timerfd working correctly on my amd64 box:

    http://www.xmailserver.org/timerfd-test.c

    [akpm@linux-foundation.org: add sys_timerfd to sys_ni.c]
    Signed-off-by: Davide Libenzi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davide Libenzi