12 Jan, 2006

1 commit


11 Jan, 2006

3 commits

  • Get rid of needless casting of kmalloc() return value in net/

    Signed-off-by: Jesper Juhl
    Signed-off-by: Andrew Morton
    Signed-off-by: David S. Miller

    Jesper Juhl
     
  • This changes some memcmp(one,two,ETH_ALEN) to compare_ether_addr(one,two).

    Signed-off-by: Kris Katterjohn
    Signed-off-by: David S. Miller

    Kris Katterjohn
     
  • The API and code have been through various bits of initial review by
    serial driver people but they definitely need to live somewhere for a
    while so the unconverted drivers can get knocked into shape, existing
    drivers that have been updated can be better tuned and bugs whacked out.

    This replaces the tty flip buffers with kmalloc objects in rings. In the
    normal situation for an IRQ driven serial port at typical speeds the
    behaviour is pretty much the same, two buffers end up allocated and the
    kernel cycles between them as before.

    When there are delays or at high speed we now behave far better as the
    buffer pool can grow a bit rather than lose characters. This also means
    that we can operate at higher speeds reliably.

    For drivers that receive characters in blocks (DMA based, USB and
    especially virtualisation) the layer allows a lot of driver specific
    code that works around the tty layer with private secondary queues to be
    removed. The IBM folks need this sort of layer, the smart serial port
    people do, the virtualisers do (because a virtualised tty typically
    operates at infinite speed rather than emulating 9600 baud).

    Finally many drivers had invalid and unsafe attempts to avoid buffer
    overflows by directly invoking tty methods extracted out of the innards
    of work queue structs. These are no longer needed and all go away. That
    fixes various random hangs with serial ports on overflow.

    The other change in here is to optimise the receive_room path that is
    used by some callers. It turns out that only one ldisc uses receive room
    except asa constant and it updates it far far less than the value is
    read. We thus make it a variable not a function call.

    I expect the code to contain bugs due to the size alone but I'll be
    watching and squashing them and feeding out new patches as it goes.

    Because the buffers now dynamically expand you should only run out of
    buffering when the kernel runs out of memory for real. That means a lot of
    the horrible hacks high performance drivers used to do just aren't needed any
    more.

    Description:

    tty_insert_flip_char is an old API and continues to work as before, as does
    tty_flip_buffer_push() [this is why many drivers dont need modification]. It
    does now also return the number of chars inserted

    There are also

    tty_buffer_request_room(tty, len)

    which asks for a buffer block of the length requested and returns the space
    found. This improves efficiency with hardware that knows how much to
    transfer.

    and tty_insert_flip_string_flags(tty, str, flags, len)

    to insert a string of characters and flags

    For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

    More description!

    At the moment tty buffers are attached directly to the tty. This is causing a
    lot of the problems related to tty layer locking, also problems at high speed
    and also with bursty data (such as occurs in virtualised environments)

    I'm working on ripping out the flip buffers and replacing them with a pool of
    dynamically allocated buffers. This allows both for old style "byte I/O"
    devices and also helps virtualisation and smart devices where large blocks of
    data suddenely materialise and need storing.

    So far so good. Lots of drivers reference tty->flip.*. Several of them also
    call directly and unsafely into function pointers it provides. This will all
    break. Most drivers can use tty_insert_flip_char which can be kept as an API
    but others need more.

    At the moment I've added the following interfaces, if people think more will
    be needed now is a good time to say

    int tty_buffer_request_room(tty, size)

    Try and ensure at least size bytes are available, returns actual room (may be
    zero). At the moment it just uses the flipbuf space but that will change.
    Repeated calls without characters being added are not cumulative. (ie if you
    call it with 1, 1, 1, and then 4 you'll have four characters of space. The
    other functions will also try and grow buffers in future but this will be a
    more efficient way when you know block sizes.

    int tty_insert_flip_char(tty, ch, flag)

    As before insert a character if there is room. Now returns 1 for success, 0
    for failure.

    int tty_insert_flip_string(tty, str, len)

    Insert a block of non error characters. Returns the number inserted.

    int tty_prepare_flip_string(tty, strptr, len)

    Adjust the buffer to allow len characters to be added. Returns a buffer
    pointer in strptr and the length available. This allows for hardware that
    needs to use functions like insl or mencpy_fromio.

    Signed-off-by: Alan Cox
    Cc: Paul Fulghum
    Signed-off-by: Hirokazu Takata
    Signed-off-by: Serge Hallyn
    Signed-off-by: Jeff Dike
    Signed-off-by: John Hawkes
    Signed-off-by: Martin Schwidefsky
    Signed-off-by: Adrian Bunk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alan Cox
     

05 Jan, 2006

2 commits


04 Jan, 2006

2 commits

  • I noticed that some of 'struct proto_ops' used in the kernel may share
    a cache line used by locks or other heavily modified data. (default
    linker alignement is 32 bytes, and L1_CACHE_LINE is 64 or 128 at
    least)

    This patch makes sure a 'struct proto_ops' can be declared as const,
    so that all cpus can share all parts of it without false sharing.

    This is not mandatory : a driver can still use a read/write structure
    if it needs to (and eventually a __read_mostly)

    I made a global stubstitute to change all existing occurences to make
    them const.

    This should reduce the possibility of false sharing on SMP, and
    speedup some socket system calls.

    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet
     
  • It also looks like there were 2 places where the test on sk_err was
    missing from the event wait logic (in sk_stream_wait_connect and
    sk_stream_wait_memory), while the rest of the sock_error() users look
    to be doing the right thing. This version of the patch fixes those,
    and cleans up a few places that were testing ->sk_err directly.

    Signed-off-by: Benjamin LaHaise
    Signed-off-by: David S. Miller

    Benjamin LaHaise
     

09 Nov, 2005

3 commits


30 Oct, 2005

1 commit

  • Bluetooth HIDP selects INPUT and it really needs it to be there - module
    depends on input core. And input core is never built on s390...

    Marked as broken on s390, for now; if somebody has better ideas, feel
    free to fix it and remove dependency...

    Signed-off-by: Al Viro
    Acked-by: Marcel Holtmann
    Signed-off-by: Linus Torvalds

    Al Viro
     

29 Oct, 2005

5 commits


09 Oct, 2005

1 commit

  • - added typedef unsigned int __nocast gfp_t;

    - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
    the same warnings as far as sparse is concerned, doesn't change
    generated code (from gcc point of view we replaced unsigned int with
    typedef) and documents what's going on far better.

    Signed-off-by: Al Viro
    Signed-off-by: Linus Torvalds

    Al Viro
     

13 Sep, 2005

2 commits


30 Aug, 2005

7 commits


06 Aug, 2005

3 commits


09 Jul, 2005

1 commit

  • This is part of the grand scheme to eliminate the qlen
    member of skb_queue_head, and subsequently remove the
    'list' member of sk_buff.

    Most users of skb_queue_len() want to know if the queue is
    empty or not, and that's trivially done with skb_queue_empty()
    which doesn't use the skb_queue_head->qlen member and instead
    uses the queue list emptyness as the test.

    Signed-off-by: David S. Miller

    David S. Miller
     

26 Apr, 2005

1 commit

  • A lot of places in there are including major.h for no reason whatsoever.
    Removed. And yes, it still builds.

    The history of that stuff is often amusing. E.g. for net/core/sock.c
    the story looks so, as far as I've been able to reconstruct it: we used
    to need major.h in net/socket.c circa 1.1.early. In 1.1.13 that need
    had disappeared, along with register_chrdev(SOCKET_MAJOR, "socket",
    &net_fops) in sock_init(). Include had not. When 1.2 -> 1.3 reorg of
    net/* had moved a lot of stuff from net/socket.c to net/core/sock.c,
    this crap had followed...

    Signed-off-by: Al Viro
    Signed-off-by: Linus Torvalds

    Al Viro
     

17 Apr, 2005

1 commit

  • 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