Eric Lee / smarc-fsl-linux-kernel

22 Jun, 2007

1 commit

  • 58229a189   posix-timers: Prevent softirq starvation by small intervals and SIG_IGN ... Browse Code »

    posix-timers which deliver an ignored signal are currently rearmed in
    the timer softirq: This is necessary because the timer needs to be
    delivered again when SIG_IGN is removed. This is not a problem, when
    the interval is reasonable.

    With high resolution timers enabled one might arm a posix timer with a
    very small interval and ignore the signal. This might lead to a
    softirq starvation when the interval is so small that the timer is
    requeued onto the softirq pending list right away.

    This problem was pointed out by Jan Kiszka. Thanks Jan !

    The correct solution would be to stop the timer, when the signal is
    ignored and rearm it when SIG_IGN is removed. Unfortunately this
    requires modification in sigaction and involves non trivial sighand
    locking. It's too late in the release cycle for such a change.

    For now we just keep the timer running and enforce that the timer only
    fires every jiffie. This does not break anything as we keep the
    overrun counter correct. It adds a little inaccuracy to the
    timer_gettime() interface, but...

    The more complex change is necessary anyway to fix another short
    coming of the current implementation, which I discovered while looking
    at this problem: A pending signal is discarded when SIG_IGN is set. In
    case that a posixtimer signal is pending then it is discarded as well,
    but when SIG_IGN is removed later nothing rearms the timer. This is
    not new, it's that way since posix timers have been merged. So nothing
    to worry about right now.

    I have a working solution to fix all of this, but the impact is too
    large for both stable and 2.6.22. I'm going to send it out for review
    in the next days.

    This should go into 2.6.21.stable as well.

    Signed-off-by: Thomas Gleixner
    Acked-by: Ingo Molnar
    Cc: Jan Kiszka
    Cc: Ulrich Drepper
    Cc: Stable Team
    Signed-off-by: Linus Torvalds

    Thomas Gleixner
     

09 May, 2007

1 commit

17 Feb, 2007

2 commits

  • 54cdfdb47   [PATCH] hrtimers: add high resolution timer support ... Browse Code »

    Implement high resolution timers on top of the hrtimers infrastructure and the
    clockevents / tick-management framework. This provides accurate timers for
    all hrtimer subsystem users.

    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar
    Cc: john stultz
    Cc: Roman Zippel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Thomas Gleixner
     
  • c9cb2e3d7   [PATCH] hrtimers: namespace and enum cleanup ... Browse Code »

    - hrtimers did not use the hrtimer_restart enum and relied on the implict
    int representation. Fix the prototypes and the functions using the enums.
    - Use seperate name spaces for the enumerations
    - Convert hrtimer_restart macro to inline function
    - Add comments

    No functional changes.

    [akpm@osdl.org: fix input driver]
    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar
    Cc: john stultz
    Cc: Roman Zippel
    Cc: Dmitry Torokhov
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Thomas Gleixner
     

12 Feb, 2007

1 commit

  • c37622296   [PATCH] Transform kmem_cache_alloc()+memset(0) -> kmem_cache_zalloc(). ... Browse Code »

    Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
    corresponding "kmem_cache_zalloc()" call.

    Signed-off-by: Robert P. J. Day
    Cc: "Luck, Tony"
    Cc: Andi Kleen
    Cc: Roland McGrath
    Cc: James Bottomley
    Cc: Greg KH
    Acked-by: Joel Becker
    Cc: Steven Whitehouse
    Cc: Jan Kara
    Cc: Michael Halcrow
    Cc: "David S. Miller"
    Cc: Stephen Smalley
    Cc: James Morris
    Cc: Chris Wright
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Robert P. J. Day
     

08 Dec, 2006

1 commit

  • e18b890bb   [PATCH] slab: remove kmem_cache_t ... Browse Code »

    Replace all uses of kmem_cache_t with struct kmem_cache.

    The patch was generated using the following script:

    #!/bin/sh
    #
    # Replace one string by another in all the kernel sources.
    #

    set -e

    for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
    quilt add $file
    sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
    mv /tmp/$$ $file
    quilt refresh
    done

    The script was run like this

    sh replace kmem_cache_t "struct kmem_cache"

    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     

04 Oct, 2006

1 commit

30 Sep, 2006

1 commit

  • 1711ef386   [PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining time in compatibility mode ... Browse Code »

    The clock_nanosleep() function does not return the time remaining when the
    sleep is interrupted by a signal.

    This patch creates a new call out, compat_clock_nanosleep_restart(), which
    handles returning the remaining time after a sleep is interrupted. This
    patch revives clock_nanosleep_restart(). It is now accessed via the new
    call out. The compat_clock_nanosleep_restart() is used for compatibility
    access.

    Since this is implemented in compatibility mode the normal path is
    virtually unaffected - no real performance impact.

    Signed-off-by: Toyo Abe
    Cc: Thomas Gleixner
    Cc: Ingo Molnar
    Cc: Roland McGrath
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Toyo Abe
     

27 Mar, 2006

3 commits

23 Mar, 2006

1 commit

  • 97d1f15b7   [PATCH] sem2mutex: kernel/ ... Browse Code »

    Semaphore to mutex conversion.

    The conversion was generated via scripts, and the result was validated
    automatically via a script as well.

    Signed-off-by: Arjan van de Ven
    Signed-off-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

17 Mar, 2006

1 commit

02 Feb, 2006

4 commits

15 Jan, 2006

1 commit

11 Jan, 2006

5 commits

14 Nov, 2005

1 commit

31 Oct, 2005

1 commit

22 Oct, 2005

1 commit

  • 25f407f0b   [PATCH] Call exit_itimers from do_exit, not __exit_signal ... Browse Code »

    When I originally moved exit_itimers into __exit_signal, that was the only
    place where we could reliably know it was the last thread in the group
    dying, without races. Since then we've gotten the signal_struct.live
    counter, and do_exit can reliably do group-wide cleanup work.

    This patch moves the call to do_exit, where it's made without locks. This
    avoids the deadlock issues that the old __exit_signal code's comment talks
    about, and the one that Oleg found recently with process CPU timers.

    [ This replaces e03d13e985d48ac4885382c9e3b1510c78bd047f, which is why
    it was just reverted. ]

    Signed-off-by: Roland McGrath
    Signed-off-by: Linus Torvalds

    Roland McGrath
     

08 Sep, 2005

1 commit

  • e752dd6cc   [PATCH] fix send_sigqueue() vs thread exit race ... Browse Code »

    posix_timer_event() first checks that the thread (SIGEV_THREAD_ID case)
    does not have PF_EXITING flag, then it calls send_sigqueue() which locks
    task list. But if the thread exits in between the kernel will oops
    (->sighand == NULL after __exit_sighand).

    This patch moves the PF_EXITING check into the send_sigqueue(), it must be
    done atomically under tasklist_lock. When send_sigqueue() detects exiting
    thread it returns -1. In that case posix_timer_event will send the signal
    to thread group.

    Also, this patch fixes task_struct use-after-free in posix_timer_event.

    Signed-off-by: Oleg Nesterov
    Cc: Thomas Gleixner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Oleg Nesterov
     

05 Aug, 2005

1 commit

29 Jul, 2005

1 commit

  • 78fa74a23   [PATCH] posix timers: fix normalization problem ... Browse Code »

    (We found this (after a customer complained) and it is in the kernel.org
    kernel. Seems that for CLOCK_MONOTONIC absolute timers and clock_nanosleep
    calls both the request time and wall_to_monotonic are subtracted prior to
    the normalize resulting in an overflow in the existing normalize test.
    This causes the result to be shifted ~4 seconds ahead instead of ~2 seconds
    back in time.)

    The normalize code in posix-timers.c fails when the tv_nsec member is ~1.2
    seconds negative. This can happen on absolute timers (and
    clock_nanosleeps) requested on CLOCK_MONOTONIC (both the request time and
    wall_to_monotonic are subtracted resulting in the possibility of a number
    close to -2 seconds.)

    This fix uses the set_normalized_timespec() (which does not have an
    overflow problem) to fix the problem and as a side effect makes the code
    cleaner.

    Signed-off-by: George Anzinger
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    George Anzinger
     

24 Jun, 2005

1 commit

  • f972be33c   [PATCH] posix-timers: use try_to_del_timer_sync() ... Browse Code »

    sys_timer_settime/sys_timer_delete needs to delete k_itimer->real.timer
    synchronously while holding ->it_lock, which is also locked in
    posix_timer_fn.

    This patch removes timer_active/set_timer_inactive which plays with
    timer_list's internals in favour of using try_to_del_timer_sync(), which
    was introduced in the previous patch.

    Signed-off-by: Oleg Nesterov
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Oleg Nesterov
     

18 Jun, 2005

1 commit

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds