Eric Lee / smarc-fsl-linux-kernel

20 May, 2011

2 commits

  • e66eed651   list: remove prefetching from regular list iterators ... Browse Code »

    This is removes the use of software prefetching from the regular list
    iterators. We don't want it. If you do want to prefetch in some
    iterator of yours, go right ahead. Just don't expect the iterator to do
    it, since normally the downsides are bigger than the upsides.

    It also replaces with , because the
    use of LIST_POISON ends up needing it. is sadly not
    self-contained, and including prefetch.h just happened to hide that.

    Suggested by David Miller (networking has a lot of regular lists that
    are often empty or a single entry, and prefetching is not going to do
    anything but add useless instructions).

    Acked-by: Ingo Molnar
    Acked-by: David S. Miller
    Cc: linux-arch@vger.kernel.org
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     
  • 75d65a425   hlist: remove software prefetching in hlist iterators ... Browse Code »

    They not only increase the code footprint, they actually make things
    slower rather than faster. On internationally acclaimed benchmarks
    ("make -j16" on an already fully built kernel source tree) the hlist
    prefetching slows down the build by up to 1%.

    (Almost all of it comes from hlist_for_each_entry_rcu() as used by
    avc_has_perm_noaudit(), which is very hot due to all the pathname
    lookups to see if there is anything to do).

    The cause seems to be two-fold:

    - on at least some Intel cores, prefetch(NULL) ends up with some
    microarchitectural stall due to the TLB miss that it incurs. The
    hlist case triggers this very commonly, since the NULL pointer is the
    last entry in the list.

    - the prefetch appears to cause more D$ activity, probably because it
    prefetches hash list entries that are never actually used (because we
    ended the search early due to a hit).

    Regardless, the numbers clearly say that the implicit prefetching is
    simply a bad idea. If some _particular_ user of the hlist iterators
    wants to prefetch the next list entry, they can do so themselves
    explicitly, rather than depend on all list iterators doing so
    implicitly.

    Acked-by: Ingo Molnar
    Acked-by: David S. Miller
    Cc: linux-arch@vger.kernel.org
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

19 Feb, 2011

1 commit

  • 3c18d4de8   Expand CONFIG_DEBUG_LIST to several other list operations ... Browse Code »

    When list debugging is enabled, we aim to readably show list corruption
    errors, and the basic list_add/list_del operations end up having extra
    debugging code in them to do some basic validation of the list entries.

    However, "list_del_init()" and "list_move[_tail]()" ended up avoiding
    the debug code due to how they were written. This fixes that.

    So the _next_ time we have list_move() problems with stale list entries,
    we'll hopefully have an easier time finding them..

    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

26 Oct, 2010

1 commit

07 Oct, 2010

1 commit

  • bcdb714c8   Drop a couple of unnecessary asm/system.h inclusions ... Browse Code »

    Drop inclusions of asm/system.h from linux/hardirq.h and linux/list.h as
    they're no longer required and prevent the M68K arch's IRQ flag handling macros
    from being made into inlined functions due to circular dependencies.

    Signed-off-by: David Howells
    Acked-by: Greg Ungerer
    Acked-by: Geert Uytterhoeven

    David Howells
     

07 Jul, 2010

2 commits

30 Jun, 2010

1 commit

  • 57439f878   fs: fix superblock iteration race ... Browse Code »

    list_for_each_entry_safe is not suitable to protect against concurrent
    modification of the list. 6754af6 introduced a race in sb walking.

    list_for_each_entry can use the trick of pinning the current entry in
    the list before we drop and retake the lock because it subsequently
    follows cur->next. However list_for_each_entry_safe saves n=cur->next
    for following before entering the loop body, so when the lock is
    dropped, n may be deleted.

    Signed-off-by: Nick Piggin
    Cc: Christoph Hellwig
    Cc: John Stultz
    Cc: Frank Mayhar
    Cc: Al Viro
    Signed-off-by: Linus Torvalds

    npiggin@suse.de
     

07 Mar, 2010

1 commit

16 Jan, 2010

1 commit

  • 5908cdc85   list: Introduce list_rotate_left() ... Browse Code »

    Bring a new list_rotate_left() helper that rotates a list to
    the left. This is useful for codes that need to round roubin
    elements which queue priority increases from tail to head.

    Signed-off-by: Frederic Weisbecker
    Acked-by: Peter Zijlstra
    Cc: Paul Mackerras
    Cc: Ingo Molnar
    Cc: Arnaldo Carvalho de Melo

    Frederic Weisbecker
     

01 Sep, 2008

1 commit

  • 673d62cc5   debugobjects: fix lockdep warning ... Browse Code »

    Daniel J. Blueman reported:
    > =======================================================
    > [ INFO: possible circular locking dependency detected ]
    > 2.6.27-rc4-224c #1
    > -------------------------------------------------------
    > hald/4680 is trying to acquire lock:
    > (&n->list_lock){++..}, at: [] add_partial+0x26/0x80
    >
    > but task is already holding lock:
    > (&obj_hash[i].lock){++..}, at: []
    > debug_object_free+0x5c/0x120

    We fix it by moving the actual freeing to outside the lock (the lock
    now only protects the list).

    The pool lock is also promoted to irq-safe (suggested by Dan). It's
    necessary because free_pool is now called outside the irq disabled
    region. So we need to protect against an interrupt handler which calls
    debug_object_init().

    [tglx@linutronix.de: added hlist_move_list helper to avoid looping
    through the list twice]

    Reported-by: Daniel J Blueman
    Signed-off-by: Vegard Nossum
    Signed-off-by: Thomas Gleixner

    Vegard Nossum
     

09 Aug, 2008

1 commit

  • 6724cce8f   list.h: fix fatal kernel-doc error ... Browse Code »

    Fix fatal multi-line kernel-doc error in list.h:
    function short description must be on one line.

    Error(linux-2.6.27-rc2-git3//include/linux/list.h:318): duplicate section name 'Description'

    Signed-off-by: Randy Dunlap
    Signed-off-by: Linus Torvalds

    Randy Dunlap
     

07 Aug, 2008

2 commits

26 Jul, 2008

1 commit

  • e0ce0da9f   lists: remove a redundant conditional definition of list_add() ... Browse Code »

    Remove the conditional surrounding the definition of list_add() from list.h
    since, if you define CONFIG_DEBUG_LIST, the definition you will subsequently
    pick up from lib/list_debug.c will be absolutely identical, at which point you
    can remove that redundant definition from list_debug.c as well.

    Signed-off-by: Robert P. J. Day
    Cc: Dave Jones
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Robert P. J. Day
     

19 May, 2008

1 commit

  • 82524746c   rcu: split list.h and move rcu-protected lists into rculist.h ... Browse Code »

    Move rcu-protected lists from list.h into a new header file rculist.h.

    This is done because list are a very used primitive structure all over the
    kernel and it's currently impossible to include other header files in this
    list.h without creating some circular dependencies.

    For example, list.h implements rcu-protected list and uses rcu_dereference()
    without including rcupdate.h. It actually compiles because users of
    rcu_dereference() are macros. Others RCU functions could be used too but
    aren't probably because of this.

    Therefore this patch creates rculist.h which includes rcupdates without to
    many changes/troubles.

    Signed-off-by: Franck Bui-Huu
    Acked-by: Paul E. McKenney
    Acked-by: Josh Triplett
    Signed-off-by: Andrew Morton
    Signed-off-by: Ingo Molnar

    Franck Bui-Huu
     

30 Apr, 2008

1 commit

29 Apr, 2008

1 commit

28 Apr, 2008

1 commit

  • 996025728   list.h: add list_is_singular() ... Browse Code »

    Add list_is_singular() to check a list has just one entry.

    list_is_singular() is useful to check whether a list_head which have been
    temporarily allocated for listing objects can be released or not.

    Signed-off-by: Masami Hiramatsu
    Cc: Peter Zijlstra
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Masami Hiramatsu
     

21 Apr, 2008

1 commit

  • cc216c5d4   Fix RCU list iterator use of 'rcu_dereference()' ... Browse Code »

    The RCU iterators used 'rcu_dereference()' on an already-fetched RCU
    pointer value, which defeats the whole point of the exercise.

    When we dereference a pointer protected by RCU, we need to make sure
    that we only fetch the value _once_, because if the compiler ends up
    re-loading it due to register pressure, the newly reloaded value could
    be different from the previously fetched one, and you get inconsistent
    results.

    Cleaned-up, fixed, and the pointless list_for_each_safe_rcu #define
    deleted by Paul Kenney.

    Acked-by: Herbert Xu
    Signed-off-by: Paul E. McKenney
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

20 Oct, 2007

1 commit

  • 8f731f7d8   kernel-api docbook: fix content problems ... Browse Code »

    Fix kernel-api docbook contents problems.

    docproc: linux-2.6.23-git13/include/asm-x86/unaligned_32.h: No such file or directory
    Warning(linux-2.6.23-git13//include/linux/list.h:482): bad line: of list entry
    Warning(linux-2.6.23-git13//mm/filemap.c:864): No description found for parameter 'ra'
    Warning(linux-2.6.23-git13//block/ll_rw_blk.c:3760): No description found for parameter 'req'
    Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'private'
    Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'cdev'

    Signed-off-by: Randy Dunlap
    Cc: Jens Axboe
    Cc: WU Fengguang
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Randy Dunlap
     

17 Oct, 2007

1 commit

  • 37c42524d   shrink_dcache_sb speedup ... Browse Code »

    This patch makes shrink_dcache_sb consistent with dentry pruning policy.

    On the first pass we iterate over dentry unused list and prepare some
    dentries for removal.

    However, since the existing code moves evicted dentries to the beginning of
    the LRU it can happen that fresh dentries from other superblocks will be
    inserted *before* our dentries.

    This can result in significant slowdown of shrink_dcache_sb(). Moreover,
    for virtual filesystems like unionfs which can call dput() during dentries
    kill existing code results in O(n^2) complexity.

    We observed 2 minutes shrink_dcache_sb() with only 35000 dentries.

    To avoid this effects we propose to isolate sb dentries at the end
    of LRU list.

    Signed-off-by: Denis V. Lunev
    Signed-off-by: Kirill Korotaev
    Signed-off-by: Andrey Mirkin
    Cc: Neil Brown
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Denis V. Lunev
     

11 Oct, 2007

1 commit

  • 768f3591e   [NETNS]: Cleanup list walking in setup_net and cleanup_net ... Browse Code »

    I proposed introducing a list_for_each_entry_continue_reverse macro
    to be used in setup_net() when unrolling the failed ->init callback.

    Here is the macro and some more cleanup in the setup_net() itself
    to remove one variable from the stack :) The same thing is for the
    cleanup_net() - the existing list_for_each_entry_reverse() is used.

    Minor, but the code looks nicer.

    Signed-off-by: Pavel Emelyanov
    Acked-by: "Eric W. Biederman"
    Signed-off-by: David S. Miller

    Pavel Emelyanov
     

13 May, 2007

1 commit

09 May, 2007

1 commit

  • b5e618181   Introduce a handy list_first_entry macro ... Browse Code »

    There are many places in the kernel where the construction like

    foo = list_entry(head->next, struct foo_struct, list);

    are used.
    The code might look more descriptive and neat if using the macro

    list_first_entry(head, type, member) \
    list_entry((head)->next, type, member)

    Here is the macro itself and the examples of its usage in the generic code.
    If it will turn out to be useful, I can prepare the set of patches to
    inject in into arch-specific code, drivers, networking, etc.

    Signed-off-by: Pavel Emelianov
    Signed-off-by: Kirill Korotaev
    Cc: Randy Dunlap
    Cc: Andi Kleen
    Cc: Zach Brown
    Cc: Davide Libenzi
    Cc: John McCutchan
    Cc: Thomas Gleixner
    Cc: Ingo Molnar
    Cc: john stultz
    Cc: Ram Pai
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Pavel Emelianov
     

12 Feb, 2007

2 commits

  • 72fd4a35a   [PATCH] Numerous fixes to kernel-doc info in source files. ... Browse Code »

    A variety of (mostly) innocuous fixes to the embedded kernel-doc content in
    source files, including:

    * make multi-line initial descriptions single line
    * denote some function names, constants and structs as such
    * change erroneous opening '/*' to '/**' in a few places
    * reword some text for clarity

    Signed-off-by: Robert P. J. Day
    Cc: "Randy.Dunlap"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Robert P. J. Day
     
  • 3678d62f0   [PATCH] add an RCU version of list splicing ... Browse Code »

    This patch is in support of the IPMI driver. I have tested this with the
    IPMI driver changes coming in the next patch.

    Add a list_splice_init_rcu() function to splice an RCU-protected list into
    another list. This takes the sync function as an argument, so one would do
    something like:

    INIT_LIST_HEAD(&list);
    list_splice_init_rcu(&source, &dest, synchronize_rcu);

    The idea being to keep the RCU API proliferation down to a dull roar.

    [akpm@osdl.org: build fix]
    Signed-off-by: Paul E. McKenney
    Signed-off-by: Corey Minyard
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Corey Minyard
     

27 Jan, 2007

1 commit

30 Sep, 2006

1 commit

15 Jul, 2006

1 commit

28 Jun, 2006

1 commit

  • c9cf55285   [PATCH] add poison.h and patch primary users ... Browse Code »

    Localize poison values into one header file for better documentation and
    easier/quicker debugging and so that the same values won't be used for
    multiple purposes.

    Use these constants in core arch., mm, driver, and fs code.

    Signed-off-by: Randy Dunlap
    Acked-by: Matt Mackall
    Cc: Paul Mackerras
    Cc: Benjamin Herrenschmidt
    Cc: "David S. Miller"
    Cc: Andi Kleen
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Randy Dunlap
     

26 Jun, 2006

2 commits

  • 8e3a67a99   [PATCH] list.h doc: change "counter" to "cursor" ... Browse Code »

    Use loop "cursor" instead of loop "counter" for list iterator descriptions.
    They are not counters, they are pointers or positions.

    Signed-off-by: Randy Dunlap
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Randy Dunlap
     
  • fe96e57d7   [PATCH] fix list.h kernel-doc ... Browse Code »

    kernel-doc:

    Put all short function descriptions on one line or if they are too long,
    omit the short description & add a Description: section for them.

    Change some list iterator descriptions to use "current" point instead of
    "existing" point.

    Signed-off-by: Randy Dunlap
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Randy Dunlap
     

23 Jun, 2006

1 commit

30 Apr, 2006

1 commit

21 Mar, 2006

2 commits

04 Feb, 2006

1 commit

  • 490d6ab17   [PATCH] list.h: don't evaluate macro args multiple times ... Browse Code »

    I noticed that list.h init functions were evaluating macro arguments
    multiple times and thought it might be nice to protect the unsuspecting
    caller. Converting the macros to inline functions seems to reduce code
    size, too. A i386 defconfig build with gcc 3.3.3 from fc4:

    text data bss dec hex filename
    3573148 565664 188828 4327640 4208d8 vmlinux.before
    3572177 565664 188828 4326669 42050d vmlinux

    add/remove: 0/0 grow/shrink: 11/144 up/down: 88/-1016 (-928)

    There was no difference in checkstack output.

    Signed-off-by: Zach Brown
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Zach Brown
     

11 Jan, 2006

1 commit

13 Dec, 2005

1 commit