Doug / smarc-fsl-linux-kernel

14 Feb, 2008

1 commit

06 Feb, 2008

1 commit

  • 0ccf831cb   lockdep: annotate epoll ... Browse Code »

    On Sat, 2008-01-05 at 13:35 -0800, Davide Libenzi wrote:

    > I remember I talked with Arjan about this time ago. Basically, since 1)
    > you can drop an epoll fd inside another epoll fd 2) callback-based wakeups
    > are used, you can see a wake_up() from inside another wake_up(), but they
    > will never refer to the same lock instance.
    > Think about:
    >
    > dfd = socket(...);
    > efd1 = epoll_create();
    > efd2 = epoll_create();
    > epoll_ctl(efd1, EPOLL_CTL_ADD, dfd, ...);
    > epoll_ctl(efd2, EPOLL_CTL_ADD, efd1, ...);
    >
    > When a packet arrives to the device underneath "dfd", the net code will
    > issue a wake_up() on its poll wake list. Epoll (efd1) has installed a
    > callback wakeup entry on that queue, and the wake_up() performed by the
    > "dfd" net code will end up in ep_poll_callback(). At this point epoll
    > (efd1) notices that it may have some event ready, so it needs to wake up
    > the waiters on its poll wait list (efd2). So it calls ep_poll_safewake()
    > that ends up in another wake_up(), after having checked about the
    > recursion constraints. That are, no more than EP_MAX_POLLWAKE_NESTS, to
    > avoid stack blasting. Never hit the same queue, to avoid loops like:
    >
    > epoll_ctl(efd2, EPOLL_CTL_ADD, efd1, ...);
    > epoll_ctl(efd3, EPOLL_CTL_ADD, efd2, ...);
    > epoll_ctl(efd4, EPOLL_CTL_ADD, efd3, ...);
    > epoll_ctl(efd1, EPOLL_CTL_ADD, efd4, ...);
    >
    > The code "if (tncur->wq == wq || ..." prevents re-entering the same
    > queue/lock.

    Since the epoll code is very careful to not nest same instance locks
    allow the recursion.

    Signed-off-by: Peter Zijlstra
    Tested-by: Stefan Richter
    Acked-by: Davide Libenzi
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     

07 Dec, 2007

2 commits

10 Jul, 2007

1 commit

31 Oct, 2006

1 commit

  • 7259f0d05   [PATCH] lockdep: annotate DECLARE_WAIT_QUEUE_HEAD ... Browse Code »

    kernel: INFO: trying to register non-static key.
    kernel: the code is fine but needs lockdep annotation.
    kernel: turning off the locking correctness validator.
    kernel: [] show_trace_log_lvl+0x58/0x16a
    kernel: [] show_trace+0xd/0x10
    kernel: [] dump_stack+0x19/0x1b
    kernel: [] __lock_acquire+0xf0/0x90d
    kernel: [] lock_acquire+0x4b/0x6b
    kernel: [] _spin_lock_irqsave+0x22/0x32
    kernel: [] prepare_to_wait+0x17/0x4b
    kernel: [] lpfc_do_work+0xdd/0xcc2 [lpfc]
    kernel: [] kthread+0xc3/0xf2
    kernel: [] kernel_thread_helper+0x5/0xb

    Another case of non-static lockdep keys; duplicate the paradigm set by
    DECLARE_COMPLETION_ONSTACK and introduce DECLARE_WAIT_QUEUE_HEAD_ONSTACK.

    Signed-off-by: Peter Zijlstra
    Cc: Greg KH
    Cc: Markus Lidel
    Acked-by: Ingo Molnar
    Cc: Arjan van de Ven
    Cc: James Bottomley
    Cc: Marcel Holtmann
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     

11 Jul, 2006

1 commit

  • 21d71f513   [PATCH] uninline init_waitqueue_head() ... Browse Code »

    allyesconfig vmlinux size delta:

    text data bss dec filename
    20736884 6073834 3075176 29885894 vmlinux.before
    20721009 6073966 3075176 29870151 vmlinux.after

    ~18 bytes per callsite, 15K of text size (~0.1%) saved.

    (as an added bonus this also removes a lockdep annotation.)

    Signed-off-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

04 Jul, 2006

2 commits

26 Apr, 2006

1 commit

07 Nov, 2005

1 commit

  • 8c65b4a60   [PATCH] fix remaining missing includes ... Browse Code »

    Fix more include file problems that surfaced since I submitted the previous
    fix-missing-includes.patch. This should now allow not to include sched.h
    from module.h, which is done by a followup patch.

    Signed-off-by: Tim Schmielau
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Tim Schmielau
     

24 Jun, 2005

1 commit

  • c43dc2fd8   [PATCH] aio: make wait_queue ->task ->private ... Browse Code »

    In the upcoming aio_down patch, it is useful to store a private data
    pointer in the kiocb's wait_queue. Since we provide our own wake up
    function and do not require the task_struct pointer, it makes sense to
    convert the task pointer into a generic private pointer.

    Signed-off-by: Benjamin LaHaise
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Benjamin LaHaise
     

25 May, 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