Doug / smarc-fsl-linux-kernel

18 Dec, 2009

1 commit

  • b6e3224fb   Revert "task_struct: make journal_info conditional" ... Browse Code »

    This reverts commit e4c570c4cb7a95dbfafa3d016d2739bf3fdfe319, as
    requested by Alexey:

    "I think I gave a good enough arguments to not merge it.
    To iterate:
    * patch makes impossible to start using ext3 on EXT3_FS=n kernels
    without reboot.
    * this is done only for one pointer on task_struct"

    None of config options which define task_struct are tristate directly
    or effectively."

    Requested-by: Alexey Dobriyan
    Acked-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

16 Dec, 2009

2 commits

  • 8f0ddf91f   Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kern… ... Browse Code »

    …el/git/tip/linux-2.6-tip

    * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits)
    clockevents: Convert to raw_spinlock
    clockevents: Make tick_device_lock static
    debugobjects: Convert to raw_spinlocks
    perf_event: Convert to raw_spinlock
    hrtimers: Convert to raw_spinlocks
    genirq: Convert irq_desc.lock to raw_spinlock
    smp: Convert smplocks to raw_spinlocks
    rtmutes: Convert rtmutex.lock to raw_spinlock
    sched: Convert pi_lock to raw_spinlock
    sched: Convert cpupri lock to raw_spinlock
    sched: Convert rt_runtime_lock to raw_spinlock
    sched: Convert rq->lock to raw_spinlock
    plist: Make plist debugging raw_spinlock aware
    bkl: Fixup core_lock fallout
    locking: Cleanup the name space completely
    locking: Further name space cleanups
    alpha: Fix fallout from locking changes
    locking: Implement new raw_spinlock
    locking: Convert raw_rwlock functions to arch_rwlock
    locking: Convert raw_rwlock to arch_rwlock
    ...

    Linus Torvalds
     
  • e4c570c4c   task_struct: make journal_info conditional ... Browse Code »

    journal_info in task_struct is used in journaling file system only. So
    introduce CONFIG_FS_JOURNAL_INFO and make it conditional.

    Signed-off-by: Hiroshi Shimamoto
    Cc: Chris Mason
    Cc: "Theodore Ts'o"
    Cc: Steven Whitehouse
    Cc: KONISHI Ryusuke
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hiroshi Shimamoto
     

15 Dec, 2009

1 commit

24 Nov, 2009

1 commit

  • b3a222e52   remove CONFIG_SECURITY_FILE_CAPABILITIES compile option ... Browse Code »

    As far as I know, all distros currently ship kernels with default
    CONFIG_SECURITY_FILE_CAPABILITIES=y. Since having the option on
    leaves a 'no_file_caps' option to boot without file capabilities,
    the main reason to keep the option is that turning it off saves
    you (on my s390x partition) 5k. In particular, vmlinux sizes
    came to:

    without patch fscaps=n: 53598392
    without patch fscaps=y: 53603406
    with this patch applied: 53603342

    with the security-next tree.

    Against this we must weigh the fact that there is no simple way for
    userspace to figure out whether file capabilities are supported,
    while things like per-process securebits, capability bounding
    sets, and adding bits to pI if CAP_SETPCAP is in pE are not supported
    with SECURITY_FILE_CAPABILITIES=n, leaving a bit of a problem for
    applications wanting to know whether they can use them and/or why
    something failed.

    It also adds another subtly different set of semantics which we must
    maintain at the risk of severe security regressions.

    So this patch removes the SECURITY_FILE_CAPABILITIES compile
    option. It drops the kernel size by about 50k over the stock
    SECURITY_FILE_CAPABILITIES=y kernel, by removing the
    cap_limit_ptraced_target() function.

    Changelog:
    Nov 20: remove cap_limit_ptraced_target() as it's logic
    was ifndef'ed.

    Signed-off-by: Serge E. Hallyn
    Acked-by: Andrew G. Morgan"
    Signed-off-by: James Morris

    Serge E. Hallyn
     

21 Sep, 2009

1 commit

  • cdd6c482c   perf: Do the big rename: Performance Counters -> Performance Events ... Browse Code »

    Bye-bye Performance Counters, welcome Performance Events!

    In the past few months the perfcounters subsystem has grown out its
    initial role of counting hardware events, and has become (and is
    becoming) a much broader generic event enumeration, reporting, logging,
    monitoring, analysis facility.

    Naming its core object 'perf_counter' and naming the subsystem
    'perfcounters' has become more and more of a misnomer. With pending
    code like hw-breakpoints support the 'counter' name is less and
    less appropriate.

    All in one, we've decided to rename the subsystem to 'performance
    events' and to propagate this rename through all fields, variables
    and API names. (in an ABI compatible fashion)

    The word 'event' is also a bit shorter than 'counter' - which makes
    it slightly more convenient to write/handle as well.

    Thanks goes to Stephane Eranian who first observed this misnomer and
    suggested a rename.

    User-space tooling and ABI compatibility is not affected - this patch
    should be function-invariant. (Also, defconfigs were not touched to
    keep the size down.)

    This patch has been generated via the following script:

    FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

    sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

    for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
    done

    FILES=$(find . -name perf_event.*)

    sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

    ... to keep it as correct as possible. This script can also be
    used by anyone who has pending perfcounters patches - it converts
    a Linux kernel tree over to the new naming. We tried to time this
    change to the point in time where the amount of pending patches
    is the smallest: the end of the merge window.

    Namespace clashes were fixed up in a preparatory patch - and some
    stylistic fallout will be fixed up in a subsequent patch.

    ( NOTE: 'counters' are still the proper terminology when we deal
    with hardware registers - and these sed scripts are a bit
    over-eager in renaming them. I've undone some of that, but
    in case there's something left where 'counter' would be
    better than 'event' we can undo that on an individual basis
    instead of touching an otherwise nicely automated patch. )

    Suggested-by: Stephane Eranian
    Acked-by: Peter Zijlstra
    Acked-by: Paul Mackerras
    Reviewed-by: Arjan van de Ven
    Cc: Mike Galbraith
    Cc: Arnaldo Carvalho de Melo
    Cc: Frederic Weisbecker
    Cc: Steven Rostedt
    Cc: Benjamin Herrenschmidt
    Cc: David Howells
    Cc: Kyle McMartin
    Cc: Martin Schwidefsky
    Cc: "David S. Miller"
    Cc: Thomas Gleixner
    Cc: "H. Peter Anvin"
    Cc:
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

29 Aug, 2009

1 commit

  • dd5d19baf   rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees ... Browse Code »

    When offlining CPUs from a multi-level tree, there is the
    possibility of offlining the last CPU from a given node when
    there are preempted RCU read-side critical sections that
    started life on one of the CPUs on that node.

    In this case, the corresponding tasks will be enqueued via the
    task_struct's rcu_node_entry list_head onto one of the
    rcu_node's blocked_tasks[] lists. These tasks need to be moved
    somewhere else so that they will prevent the current grace
    period from ending. That somewhere is the root rcu_node.

    Signed-off-by: Paul E. McKenney
    Cc: laijs@cn.fujitsu.com
    Cc: dipankar@in.ibm.com
    Cc: akpm@linux-foundation.org
    Cc: mathieu.desnoyers@polymtl.ca
    Cc: josht@linux.vnet.ibm.com
    Cc: dvhltc@us.ibm.com
    Cc: niv@us.ibm.com
    Cc: peterz@infradead.org
    Cc: rostedt@goodmis.org
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Paul E. McKenney
     

23 Aug, 2009

2 commits

  • 6b3ef48ad   rcu: Remove CONFIG_PREEMPT_RCU ... Browse Code »

    Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no
    further need for CONFIG_PREEMPT_RCU. Remove it, along with
    whatever subtle bugs it may (or may not) contain.

    Signed-off-by: Paul E. McKenney
    Cc: laijs@cn.fujitsu.com
    Cc: dipankar@in.ibm.com
    Cc: akpm@linux-foundation.org
    Cc: mathieu.desnoyers@polymtl.ca
    Cc: josht@linux.vnet.ibm.com
    Cc: dvhltc@us.ibm.com
    Cc: niv@us.ibm.com
    Cc: peterz@infradead.org
    Cc: rostedt@goodmis.org
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Paul E. McKenney
     
  • f41d911f8   rcu: Merge preemptable-RCU functionality into hierarchical RCU ... Browse Code »

    Create a kernel/rcutree_plugin.h file that contains definitions
    for preemptable RCU (or, under the #else branch of the #ifdef,
    empty definitions for the classic non-preemptable semantics).
    These definitions fit into plugins defined in kernel/rcutree.c
    for this purpose.

    This variant of preemptable RCU uses a new algorithm whose
    read-side expense is roughly that of classic hierarchical RCU
    under CONFIG_PREEMPT. This new algorithm's update-side expense
    is similar to that of classic hierarchical RCU, and, in absence
    of read-side preemption or blocking, is exactly that of classic
    hierarchical RCU. Perhaps more important, this new algorithm
    has a much simpler implementation, saving well over 1,000 lines
    of code compared to mainline's implementation of preemptable
    RCU, which will hopefully be retired in favor of this new
    algorithm.

    The simplifications are obtained by maintaining per-task
    nesting state for running tasks, and using a simple
    lock-protected algorithm to handle accounting when tasks block
    within RCU read-side critical sections, making use of lessons
    learned while creating numerous user-level RCU implementations
    over the past 18 months.

    Signed-off-by: Paul E. McKenney
    Cc: laijs@cn.fujitsu.com
    Cc: dipankar@in.ibm.com
    Cc: akpm@linux-foundation.org
    Cc: mathieu.desnoyers@polymtl.ca
    Cc: josht@linux.vnet.ibm.com
    Cc: dvhltc@us.ibm.com
    Cc: niv@us.ibm.com
    Cc: peterz@infradead.org
    Cc: rostedt@goodmis.org
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Paul E. McKenney
     

27 Jun, 2009

1 commit

  • 857eceebd   Add new __init_task_data macro to be used in arch init_task.c files. ... Browse Code »

    This patch is preparation for replacing most ".data.init_task" in the
    kernel with macros, so that the section name can later be changed
    without having to touch a lot of the kernel.

    The long-term goal here is to be able to change the kernel's magic
    section names to those that are compatible with -ffunction-sections
    -fdata-sections. This requires renaming all magic sections with names
    of the form ".data.foo".

    Signed-off-by: Tim Abbott
    Signed-off-by: Sam Ravnborg

    Tim Abbott
     

17 Jun, 2009

1 commit

  • bb1f17b03   mm: consolidate init_mm definition ... Browse Code »

    * create mm/init-mm.c, move init_mm there
    * remove INIT_MM, initialize init_mm with C99 initializer
    * unexport init_mm on all arches:

    init_mm is already unexported on x86.

    One strange place is some OMAP driver (drivers/video/omap/) which
    won't build modular, but it's already wants get_vm_area() export.
    Somebody should look there.

    [akpm@linux-foundation.org: add missing #includes]
    Signed-off-by: Alexey Dobriyan
    Cc: Mike Frysinger
    Cc: Americo Wang
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexey Dobriyan
     

12 Jun, 2009

2 commits

  • 8a1ca8ced   Merge branch 'perfcounters-for-linus' of git://git.kernel.org/pub/scm/linux/kern… ... Browse Code »

    …el/git/tip/linux-2.6-tip

    * 'perfcounters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (574 commits)
    perf_counter: Turn off by default
    perf_counter: Add counter->id to the throttle event
    perf_counter: Better align code
    perf_counter: Rename L2 to LL cache
    perf_counter: Standardize event names
    perf_counter: Rename enums
    perf_counter tools: Clean up u64 usage
    perf_counter: Rename perf_counter_limit sysctl
    perf_counter: More paranoia settings
    perf_counter: powerpc: Implement generalized cache events for POWER processors
    perf_counters: powerpc: Add support for POWER7 processors
    perf_counter: Accurate period data
    perf_counter: Introduce struct for sample data
    perf_counter tools: Normalize data using per sample period data
    perf_counter: Annotate exit ctx recursion
    perf_counter tools: Propagate signals properly
    perf_counter tools: Small frequency related fixes
    perf_counter: More aggressive frequency adjustment
    perf_counter/x86: Fix the model number of Intel Core2 processors
    perf_counter, x86: Correct some event and umask values for Intel processors
    ...

    Linus Torvalds
     
  • 3296ca27f   Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorri… ... Browse Code »

    …s/security-testing-2.6

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (44 commits)
    nommu: Provide mmap_min_addr definition.
    TOMOYO: Add description of lists and structures.
    TOMOYO: Remove unused field.
    integrity: ima audit dentry_open failure
    TOMOYO: Remove unused parameter.
    security: use mmap_min_addr indepedently of security models
    TOMOYO: Simplify policy reader.
    TOMOYO: Remove redundant markers.
    SELinux: define audit permissions for audit tree netlink messages
    TOMOYO: Remove unused mutex.
    tomoyo: avoid get+put of task_struct
    smack: Remove redundant initialization.
    integrity: nfsd imbalance bug fix
    rootplug: Remove redundant initialization.
    smack: do not beyond ARRAY_SIZE of data
    integrity: move ima_counts_get
    integrity: path_check update
    IMA: Add __init notation to ima functions
    IMA: Minimal IMA policy and boot param for TCB IMA policy
    selinux: remove obsolete read buffer limit from sel_read_bool
    ...

    Linus Torvalds
     

11 Jun, 2009

1 commit

24 May, 2009

1 commit

  • 082ff5a27   perf_counter: Change pctrl() behaviour ... Browse Code »

    Instead of en/dis-abling all counters acting on a particular
    task, en/dis- able all counters we created.

    [ v2: fix crash on first counter enable ]

    Signed-off-by: Peter Zijlstra
    Cc: Paul Mackerras
    Cc: Corey Ashford
    Cc: Arnaldo Carvalho de Melo
    Cc: John Kacur
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

22 May, 2009

1 commit

  • a63eaf34a   perf_counter: Dynamically allocate tasks' perf_counter_context struct ... Browse Code »

    This replaces the struct perf_counter_context in the task_struct with
    a pointer to a dynamically allocated perf_counter_context struct. The
    main reason for doing is this is to allow us to transfer a
    perf_counter_context from one task to another when we do lazy PMU
    switching in a later patch.

    This has a few side-benefits: the task_struct becomes a little smaller,
    we save some memory because only tasks that have perf_counters attached
    get a perf_counter_context allocated for them, and we can remove the
    inclusion of in sched.h, meaning that we don't
    end up recompiling nearly everything whenever perf_counter.h changes.

    The perf_counter_context structures are reference-counted and freed
    when the last reference is dropped. A context can have references
    from its task and the counters on its task. Counters can outlive the
    task so it is possible that a context will be freed well after its
    task has exited.

    Contexts are allocated on fork if the parent had a context, or
    otherwise the first time that a per-task counter is created on a task.
    In the latter case, we set the context pointer in the task struct
    locklessly using an atomic compare-and-exchange operation in case we
    raced with some other task in creating a context for the subject task.

    This also removes the task pointer from the perf_counter struct. The
    task pointer was not used anywhere and would make it harder to move a
    context from one task to another. Anything that needed to know which
    task a counter was attached to was already using counter->ctx->task.

    The __perf_counter_init_context function moves up in perf_counter.c
    so that it can be called from find_get_context, and now initializes
    the refcount, but is otherwise unchanged.

    We were potentially calling list_del_counter twice: once from
    __perf_counter_exit_task when the task exits and once from
    __perf_counter_remove_from_context when the counter's fd gets closed.
    This adds a check in list_del_counter so it doesn't do anything if
    the counter has already been removed from the lists.

    Since perf_counter_task_sched_in doesn't do anything if the task doesn't
    have a context, and leaves cpuctx->task_ctx = NULL, this adds code to
    __perf_install_in_context to set cpuctx->task_ctx if necessary, i.e. in
    the case where the current task adds the first counter to itself and
    thus creates a context for itself.

    This also adds similar code to __perf_counter_enable to handle a
    similar situation which can arise when the counters have been disabled
    using prctl; that also leaves cpuctx->task_ctx = NULL.

    [ Impact: refactor counter context management to prepare for new feature ]

    Signed-off-by: Paul Mackerras
    Acked-by: Peter Zijlstra
    Cc: Corey Ashford
    Cc: Marcelo Tosatti
    Cc: Arnaldo Carvalho de Melo
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Paul Mackerras
     

11 May, 2009

1 commit

07 May, 2009

1 commit

29 Apr, 2009

1 commit

18 Apr, 2009

1 commit

  • 261842b7c   tracing: add same level recursion detection ... Browse Code »

    The tracing infrastructure allows for recursion. That is, an interrupt
    may interrupt the act of tracing an event, and that interrupt may very well
    perform its own trace. This is a recursive trace, and is fine to do.

    The problem arises when there is a bug, and the utility doing the trace
    calls something that recurses back into the tracer. This recursion is not
    caused by an external event like an interrupt, but by code that is not
    expected to recurse. The result could be a lockup.

    This patch adds a bitmask to the task structure that keeps track
    of the trace recursion. To find the interrupt depth, the following
    algorithm is used:

    level = hardirq_count() + softirq_count() + in_nmi;

    Here, level will be the depth of interrutps and softirqs, and even handles
    the nmi. Then the corresponding bit is set in the recursion bitmask.
    If the bit was already set, we know we had a recursion at the same level
    and we warn about it and fail the writing to the buffer.

    After the data has been committed to the buffer, we clear the bit.
    No atomics are needed. The only races are with interrupts and they reset
    the bitmask before returning anywy.

    [ Impact: detect same irq level trace recursion ]

    Signed-off-by: Steven Rostedt

    Steven Rostedt
     

14 Apr, 2009

1 commit

  • 17a5138d2   aio: remove INIT_KIOCTX ... Browse Code »

    Unused after 20dcae32439384b6863c626bb3b2a09bed65b33e aka
    "[PATCH] aio: remove kioctx from mm_struct".

    Signed-off-by: Alexey Dobriyan
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexey Dobriyan
     

08 Apr, 2009

2 commits

  • 5ea472a77   Merge commit 'v2.6.30-rc1' into perfcounters/core ... Browse Code »

    Conflicts:
    arch/powerpc/include/asm/systbl.h
    arch/powerpc/include/asm/unistd.h
    include/linux/init_task.h

    Merge reason: the conflicts are non-trivial: PowerPC placement
    of sys_perf_counter_open has to be mixed with the
    new preadv/pwrite syscalls.

    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • c93f216b5   Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/ker… ... Browse Code »

    …nel/git/tip/linux-2.6-tip

    * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
    branch tracer, intel-iommu: fix build with CONFIG_BRANCH_TRACER=y
    branch tracer: Fix for enabling branch profiling makes sparse unusable
    ftrace: Correct a text align for event format output
    Update /debug/tracing/README
    tracing/ftrace: alloc the started cpumask for the trace file
    tracing, x86: remove duplicated #include
    ftrace: Add check of sched_stopped for probe_sched_wakeup
    function-graph: add proper initialization for init task
    tracing/ftrace: fix missing include string.h
    tracing: fix incorrect return type of ns2usecs()
    tracing: remove CALLER_ADDR2 from wakeup tracer
    blktrace: fix pdu_len when tracing packet command requests
    blktrace: small cleanup in blk_msg_write()
    blktrace: NUL-terminate user space messages
    tracing: move scripts/trace/power.pl to scripts/tracing/power.pl

    Linus Torvalds
     

07 Apr, 2009

2 commits

  • 86665c75d   Merge branch 'tracing/urgent' into tracing/ftrace Browse Code »
    Ingo Molnar
     
  • 5ac9f6226   function-graph: add proper initialization for init task ... Browse Code »

    Impact: fix to crash going to kexec

    The init task did not properly initialize the function graph pointers.
    Altough these pointers are NULL, they can not be assumed to be NULL
    for the init task, and must still be properly initialize.

    This usually is not an issue since a problem only arises when a task
    exits, and the init tasks do not usually exit. But when doing tests
    with kexec, the init tasks do exit, and the bug appears.

    This patch properly initializes the init tasks function graph data
    structures.

    Reported-and-Tested-by: Yinghai Lu
    LKML-Reference:
    Signed-off-by: Steven Rostedt
    Signed-off-by: Ingo Molnar

    Steven Rostedt
     

06 Apr, 2009

2 commits

  • 01ef09d9f   perf_counter: fix uninitialized usage of event_list ... Browse Code »

    Impact: fix boot crash

    When doing the generic context switch event I ran into some early
    boot hangs, which were caused by inf func recursion (event, fault,
    event, fault).

    I eventually tracked it down to event_list not being initialized
    at the time of the first event. Fix this.

    Signed-off-by: Peter Zijlstra
    Cc: Paul Mackerras
    Cc: Steven Rostedt
    Orig-LKML-Reference:
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     
  • f541ae326   Merge branch 'linus' into perfcounters/core-v2 ... Browse Code »

    Merge reason: we have gathered quite a few conflicts, need to merge upstream

    Conflicts:
    arch/powerpc/kernel/Makefile
    arch/x86/ia32/ia32entry.S
    arch/x86/include/asm/hardirq.h
    arch/x86/include/asm/unistd_32.h
    arch/x86/include/asm/unistd_64.h
    arch/x86/kernel/cpu/common.c
    arch/x86/kernel/irq.c
    arch/x86/kernel/syscall_table_32.S
    arch/x86/mm/iomap_32.c
    include/linux/sched.h
    kernel/Makefile

    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

16 Feb, 2009

1 commit

13 Feb, 2009

1 commit

11 Feb, 2009

1 commit

09 Feb, 2009

1 commit

05 Feb, 2009

1 commit

  • 4cd4c1b40   timers: split process wide cpu clocks/timers ... Browse Code »

    Change the process wide cpu timers/clocks so that we:

    1) don't mess up the kernel with too many threads,
    2) don't have a per-cpu allocation for each process,
    3) have no impact when not used.

    In order to accomplish this we're going to split it into two parts:

    - clocks; which can take all the time they want since they run
    from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID)

    - timers; which need constant time sampling but since they're
    explicity used, the user can pay the overhead.

    The clock readout will go back to a full sum of the thread group, while the
    timers will run of a global 'clock' that only runs when needed, so only
    programs that make use of the facility pay the price.

    Signed-off-by: Peter Zijlstra
    Reviewed-by: Ingo Molnar
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

11 Jan, 2009

2 commits

08 Jan, 2009

1 commit

  • 490dea45d   itimers: remove the per-cpu-ish-ness ... Browse Code »

    Either we bounce once cacheline per cpu per tick, yielding n^2 bounces
    or we just bounce a single..

    Also, using per-cpu allocations for the thread-groups complicates the
    per-cpu allocator in that its currently aimed to be a fixed sized
    allocator and the only possible extention to that would be vmap based,
    which is seriously constrained on 32 bit archs.

    So making the per-cpu memory requirement depend on the number of
    processes is an issue.

    Lastly, it didn't deal with cpu-hotplug, although admittedly that might
    be fixable.

    Signed-off-by: Peter Zijlstra
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

01 Jan, 2009

1 commit

29 Dec, 2008

2 commits

  • 917b627d4   sched: create "pushable_tasks" list to limit pushing to one attempt ... Browse Code »

    The RT scheduler employs a "push/pull" design to actively balance tasks
    within the system (on a per disjoint cpuset basis). When a task is
    awoken, it is immediately determined if there are any lower priority
    cpus which should be preempted. This is opposed to the way normal
    SCHED_OTHER tasks behave, which will wait for a periodic rebalancing
    operation to occur before spreading out load.

    When a particular RQ has more than 1 active RT task, it is said to
    be in an "overloaded" state. Once this occurs, the system enters
    the active balancing mode, where it will try to push the task away,
    or persuade a different cpu to pull it over. The system will stay
    in this state until the system falls back below the lock for certain workloads, and by making sure the algorithm
    considers all eligible tasks in the system.

    [ rostedt: added a couple more BUG_ONs ]

    Signed-off-by: Gregory Haskins
    Acked-by: Steven Rostedt

    Gregory Haskins
     
  • e1df95767   Merge branch 'linus' into perfcounters/core ... Browse Code »

    Conflicts:
    fs/exec.c
    include/linux/init_task.h

    Simple context conflicts.

    Ingo Molnar
     

23 Dec, 2008

2 commits