25 May, 2012

1 commit

  • Pull timer updates from Thomas Gleixner.

    Various trivial conflict fixups in arch Kconfig due to addition of
    unrelated entries nearby. And one slightly more subtle one for sparc32
    (new user of GENERIC_CLOCKEVENTS), fixed up as per Thomas.

    * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
    timekeeping: Fix a few minor newline issues.
    time: remove obsolete declaration
    ntp: Fix a stale comment and a few stray newlines.
    ntp: Correct TAI offset during leap second
    timers: Fixup the Kconfig consolidation fallout
    x86: Use generic time config
    unicore32: Use generic time config
    um: Use generic time config
    tile: Use generic time config
    sparc: Use: generic time config
    sh: Use generic time config
    score: Use generic time config
    s390: Use generic time config
    openrisc: Use generic time config
    powerpc: Use generic time config
    mn10300: Use generic time config
    mips: Use generic time config
    microblaze: Use generic time config
    m68k: Use generic time config
    m32r: Use generic time config
    ...

    Linus Torvalds
     

24 May, 2012

2 commits

  • Pull user namespace enhancements from Eric Biederman:
    "This is a course correction for the user namespace, so that we can
    reach an inexpensive, maintainable, and reasonably complete
    implementation.

    Highlights:
    - Config guards make it impossible to enable the user namespace and
    code that has not been converted to be user namespace safe.

    - Use of the new kuid_t type ensures the if you somehow get past the
    config guards the kernel will encounter type errors if you enable
    user namespaces and attempt to compile in code whose permission
    checks have not been updated to be user namespace safe.

    - All uids from child user namespaces are mapped into the initial
    user namespace before they are processed. Removing the need to add
    an additional check to see if the user namespace of the compared
    uids remains the same.

    - With the user namespaces compiled out the performance is as good or
    better than it is today.

    - For most operations absolutely nothing changes performance or
    operationally with the user namespace enabled.

    - The worst case performance I could come up with was timing 1
    billion cache cold stat operations with the user namespace code
    enabled. This went from 156s to 164s on my laptop (or 156ns to
    164ns per stat operation).

    - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
    Most uid/gid setting system calls treat these value specially
    anyway so attempting to use -1 as a uid would likely cause
    entertaining failures in userspace.

    - If setuid is called with a uid that can not be mapped setuid fails.
    I have looked at sendmail, login, ssh and every other program I
    could think of that would call setuid and they all check for and
    handle the case where setuid fails.

    - If stat or a similar system call is called from a context in which
    we can not map a uid we lie and return overflowuid. The LFS
    experience suggests not lying and returning an error code might be
    better, but the historical precedent with uids is different and I
    can not think of anything that would break by lying about a uid we
    can't map.

    - Capabilities are localized to the current user namespace making it
    safe to give the initial user in a user namespace all capabilities.

    My git tree covers all of the modifications needed to convert the core
    kernel and enough changes to make a system bootable to runlevel 1."

    Fix up trivial conflicts due to nearby independent changes in fs/stat.c

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
    userns: Silence silly gcc warning.
    cred: use correct cred accessor with regards to rcu read lock
    userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
    userns: Convert cgroup permission checks to use uid_eq
    userns: Convert tmpfs to use kuid and kgid where appropriate
    userns: Convert sysfs to use kgid/kuid where appropriate
    userns: Convert sysctl permission checks to use kuid and kgids.
    userns: Convert proc to use kuid/kgid where appropriate
    userns: Convert ext4 to user kuid/kgid where appropriate
    userns: Convert ext3 to use kuid/kgid where appropriate
    userns: Convert ext2 to use kuid/kgid where appropriate.
    userns: Convert devpts to use kuid/kgid where appropriate
    userns: Convert binary formats to use kuid/kgid where appropriate
    userns: Add negative depends on entries to avoid building code that is userns unsafe
    userns: signal remove unnecessary map_cred_ns
    userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
    userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
    userns: Convert stat to return values mapped from kuids and kgids
    userns: Convert user specfied uids and gids in chown into kuids and kgid
    userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
    ...

    Linus Torvalds
     
  • Pull exception table generation updates from Ingo Molnar:
    "The biggest change here is to allow the build-time sorting of the
    exception table, to speed up booting. This is achieved by the
    architecture enabling BUILDTIME_EXTABLE_SORT. This option is enabled
    for x86 and MIPS currently.

    On x86 a number of fixes and changes were needed to allow build-time
    sorting of the exception table, in particular a relocation invariant
    exception table format was needed. This required the abstracting out
    of exception table protocol and the removal of 20 years of accumulated
    assumptions about the x86 exception table format.

    While at it, this tree also cleans up various other aspects of
    exception handling, such as early(er) exception handling for
    rdmsr_safe() et al.

    All in one, as the result of these changes the x86 exception code is
    now pretty nice and modern. As an added bonus any regressions in this
    code will be early and violent crashes, so if you see any of those,
    you'll know whom to blame!"

    Fix up trivial conflicts in arch/{mips,x86}/Kconfig files due to nearby
    modifications of other core architecture options.

    * 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
    Revert "x86, extable: Disable presorted exception table for now"
    scripts/sortextable: Handle relative entries, and other cleanups
    x86, extable: Switch to relative exception table entries
    x86, extable: Disable presorted exception table for now
    x86, extable: Add _ASM_EXTABLE_EX() macro
    x86, extable: Remove open-coded exception table entries in arch/x86/ia32/ia32entry.S
    x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/xsave.h
    x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/kvm_host.h
    x86, extable: Remove the now-unused __ASM_EX_SEC macros
    x86, extable: Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S
    x86, extable: Remove open-coded exception table entries in arch/x86/um/checksum_32.S
    x86, extable: Remove open-coded exception table entries in arch/x86/lib/usercopy_32.c
    x86, extable: Remove open-coded exception table entries in arch/x86/lib/putuser.S
    x86, extable: Remove open-coded exception table entries in arch/x86/lib/getuser.S
    x86, extable: Remove open-coded exception table entries in arch/x86/lib/csum-copy_64.S
    x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_nocache_64.S
    x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_64.S
    x86, extable: Remove open-coded exception table entries in arch/x86/lib/checksum_32.S
    x86, extable: Remove open-coded exception table entries in arch/x86/kernel/test_rodata.c
    x86, extable: Remove open-coded exception table entries in arch/x86/kernel/entry_64.S
    ...

    Linus Torvalds
     

23 May, 2012

2 commits

  • Pull perf changes from Ingo Molnar:
    "Lots of changes:

    - (much) improved assembly annotation support in perf report, with
    jump visualization, searching, navigation, visual output
    improvements and more.

    - kernel support for AMD IBS PMU hardware features. Notably 'perf
    record -e cycles:p' and 'perf top -e cycles:p' should work without
    skid now, like PEBS does on the Intel side, because it takes
    advantage of IBS transparently.

    - the libtracevents library: it is the first step towards unifying
    tracing tooling and perf, and it also gives a tracing library for
    external tools like powertop to rely on.

    - infrastructure: various improvements and refactoring of the UI
    modules and related code

    - infrastructure: cleanup and simplification of the profiling
    targets code (--uid, --pid, --tid, --cpu, --all-cpus, etc.)

    - tons of robustness fixes all around

    - various ftrace updates: speedups, cleanups, robustness
    improvements.

    - typing 'make' in tools/ will now give you a menu of projects to
    build and a short help text to explain what each does.

    - ... and lots of other changes I forgot to list.

    The perf record make bzImage + perf report regression you reported
    should be fixed."

    * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (166 commits)
    tracing: Remove kernel_lock annotations
    tracing: Fix initial buffer_size_kb state
    ring-buffer: Merge separate resize loops
    perf evsel: Create events initially disabled -- again
    perf tools: Split term type into value type and term type
    perf hists: Fix callchain ip printf format
    perf target: Add uses_mmap field
    ftrace: Remove selecting FRAME_POINTER with FUNCTION_TRACER
    ftrace/x86: Have x86 ftrace use the ftrace_modify_all_code()
    ftrace: Make ftrace_modify_all_code() global for archs to use
    ftrace: Return record ip addr for ftrace_location()
    ftrace: Consolidate ftrace_location() and ftrace_text_reserved()
    ftrace: Speed up search by skipping pages by address
    ftrace: Remove extra helper functions
    ftrace: Sort all function addresses, not just per page
    tracing: change CPU ring buffer state from tracing_cpumask
    tracing: Check return value of tracing_dentry_percpu()
    ring-buffer: Reset head page before running self test
    ring-buffer: Add integrity check at end of iter read
    ring-buffer: Make addition of pages in ring buffer atomic
    ...

    Linus Torvalds
     
  • Pull driver core updates from Greg Kroah-Hartman:
    "Here's the driver core, and other driver subsystems, pull request for
    the 3.5-rc1 merge window.

    Outside of a few minor driver core changes, we ended up with the
    following different subsystem and core changes as well, due to
    interdependancies on the driver core:
    - hyperv driver updates
    - drivers/memory being created and some drivers moved into it
    - extcon driver subsystem created out of the old Android staging
    switch driver code
    - dynamic debug updates
    - printk rework, and /dev/kmsg changes

    All of this has been tested in the linux-next releases for a few weeks
    with no reported problems.

    Signed-off-by: Greg Kroah-Hartman "

    Fix up conflicts in drivers/extcon/extcon-max8997.c where git noticed
    that a patch to the deleted drivers/misc/max8997-muic.c driver needs to
    be applied to this one.

    * tag 'driver-core-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (90 commits)
    uio_pdrv_genirq: get irq through platform resource if not set otherwise
    memory: tegra{20,30}-mc: Remove empty *_remove()
    printk() - isolate KERN_CONT users from ordinary complete lines
    sysfs: get rid of some lockdep false positives
    Drivers: hv: util: Properly handle version negotiations.
    Drivers: hv: Get rid of an unnecessary check in vmbus_prep_negotiate_resp()
    memory: tegra{20,30}-mc: Use dev_err_ratelimited()
    driver core: Add dev_*_ratelimited() family
    Driver Core: don't oops with unregistered driver in driver_find_device()
    printk() - restore prefix/timestamp printing for multi-newline strings
    printk: add stub for prepend_timestamp()
    ARM: tegra30: Make MC optional in Kconfig
    ARM: tegra20: Make MC optional in Kconfig
    ARM: tegra30: MC: Remove unnecessary BUG*()
    ARM: tegra20: MC: Remove unnecessary BUG*()
    printk: correctly align __log_buf
    ARM: tegra30: Add Tegra Memory Controller(MC) driver
    ARM: tegra20: Add Tegra Memory Controller(MC) driver
    printk() - restore timestamp printing at console output
    printk() - do not merge continuation lines of different threads
    ...

    Linus Torvalds
     

22 May, 2012

4 commits

  • Pull smp hotplug cleanups from Thomas Gleixner:
    "This series is merily a cleanup of code copied around in arch/* and
    not changing any of the real cpu hotplug horrors yet. I wish I'd had
    something more substantial for 3.5, but I underestimated the lurking
    horror..."

    Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and
    arch/sparc/include/asm/thread_info_32.h

    * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
    um: Remove leftover declaration of alloc_task_struct_node()
    task_allocator: Use config switches instead of magic defines
    sparc: Use common threadinfo allocator
    score: Use common threadinfo allocator
    sh-use-common-threadinfo-allocator
    mn10300: Use common threadinfo allocator
    powerpc: Use common threadinfo allocator
    mips: Use common threadinfo allocator
    hexagon: Use common threadinfo allocator
    m32r: Use common threadinfo allocator
    frv: Use common threadinfo allocator
    cris: Use common threadinfo allocator
    x86: Use common threadinfo allocator
    c6x: Use common threadinfo allocator
    fork: Provide kmemcache based thread_info allocator
    tile: Use common threadinfo allocator
    fork: Provide weak arch_release_[task_struct|thread_info] functions
    fork: Move thread info gfp flags to header
    fork: Remove the weak insanity
    sh: Remove cpu_idle_wait()
    ...

    Linus Torvalds
     
  • Pull RCU changes from Ingo Molnar:
    "This is the v3.5 RCU tree from Paul E. McKenney:

    1) A set of improvements and fixes to the RCU_FAST_NO_HZ feature (with
    more on the way for 3.6). Posted to LKML:
    https://lkml.org/lkml/2012/4/23/324 (commits 1-3 and 5),
    https://lkml.org/lkml/2012/4/16/611 (commit 4),
    https://lkml.org/lkml/2012/4/30/390 (commit 6), and
    https://lkml.org/lkml/2012/5/4/410 (commit 7, combined with
    the other commits for the convenience of the tester).

    2) Changes to make rcu_barrier() avoid disrupting execution of CPUs
    that have no RCU callbacks. Posted to LKML:
    https://lkml.org/lkml/2012/4/23/322.

    3) A couple of commits that improve the efficiency of the interaction
    between preemptible RCU and the scheduler, these two being all that
    survived an abortive attempt to allow preemptible RCU's
    __rcu_read_lock() to be inlined. The full set was posted to LKML at
    https://lkml.org/lkml/2012/4/14/143, and the first and third patches
    of that set remain.

    4) Lai Jiangshan's algorithmic implementation of SRCU, which includes
    call_srcu() and srcu_barrier(). A major feature of this new
    implementation is that synchronize_srcu() no longer disturbs the
    execution of other CPUs. This work is based on earlier
    implementations by Peter Zijlstra and Paul E. McKenney. Posted to
    LKML: https://lkml.org/lkml/2012/2/22/82.

    5) A number of miscellaneous bug fixes and improvements which were
    posted to LKML at: https://lkml.org/lkml/2012/4/23/353 with
    subsequent updates posted to LKML."

    * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
    rcu: Make rcu_barrier() less disruptive
    rcu: Explicitly initialize RCU_FAST_NO_HZ per-CPU variables
    rcu: Make RCU_FAST_NO_HZ handle timer migration
    rcu: Update RCU maintainership
    rcu: Make exit_rcu() more precise and consolidate
    rcu: Move PREEMPT_RCU preemption to switch_to() invocation
    rcu: Ensure that RCU_FAST_NO_HZ timers expire on correct CPU
    rcu: Add rcutorture test for call_srcu()
    rcu: Implement per-domain single-threaded call_srcu() state machine
    rcu: Use single value to handle expedited SRCU grace periods
    rcu: Improve srcu_readers_active_idx()'s cache locality
    rcu: Remove unused srcu_barrier()
    rcu: Implement a variant of Peter's SRCU algorithm
    rcu: Improve SRCU's wait_idx() comments
    rcu: Flip ->completed only once per SRCU grace period
    rcu: Increment upper bit only for srcu_read_lock()
    rcu: Remove fast check path from __synchronize_srcu()
    rcu: Direct algorithmic SRCU implementation
    rcu: Introduce rcutorture testing for rcu_barrier()
    timer: Fix mod_timer_pinned() header comment
    ...

    Linus Torvalds
     
  • Sigh, I missed to check which architecture Kconfig files actually
    include the core Kconfig file. There are a few which did not. So we
    broke them.

    Instead of adding the includes to those, we are better off to move the
    include to init/Kconfig like we did already with irqs and others.

    This does not change anything for the architectures using the old
    style periodic timer mode. It just solves the build wreckage there.

    For those architectures which use the clock events infrastructure it
    moves the include of the core Kconfig file to "General setup" which is
    a way more logical place than having it at random locations specified
    by the architecture specific Kconfigs.

    Reported-by: Ingo Molnar
    Cc: Anna-Maria Gleixner
    Signed-off-by: Thomas Gleixner

    Thomas Gleixner
     
  • During early boot, when the scheduler hasn't really been fully set up,
    we really can't do blocking allocations because with certain (dubious)
    configurations the "might_resched()" calls can actually result in
    scheduling events.

    We could just make such users always use GFP_ATOMIC, but quite often the
    code that does the allocation isn't really aware of the fact that the
    scheduler isn't up yet, and forcing that kind of random knowledge on the
    initialization code is just annoying and not good for anybody.

    And we actually have a the 'gfp_allowed_mask' exactly for this reason:
    it's just that the kernel init sequence happens to set it to allow
    blocking allocations much too early.

    So move the 'gfp_allowed_mask' initialization from 'start_kernel()'
    (which is some of the earliest init code, and runs with preemption
    disabled for good reasons) into 'kernel_init()'. kernel_init() is run
    in the newly created thread that will become the 'init' process, as
    opposed to the early startup code that runs within the context of what
    will be the first idle thread.

    So by the time we reach 'kernel_init()', we know that the scheduler must
    be at least limping along, because we've already scheduled from the idle
    thread into the init thread.

    Reported-by: Steven Rostedt
    Cc: David Rientjes
    Cc: stable@vger.kernel.org
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

19 May, 2012

1 commit

  • Merge reason: We are going to queue up a dependent patch:

    "perf tools: Move parse event automated tests to separated object"

    That depends on:

    commit e7c72d8
    perf tools: Add 'G' and 'H' modifiers to event parsing

    Conflicts:
    tools/perf/builtin-stat.c

    Conflicted with the recent 'perf_target' patches when checking the
    result of perf_evsel open routines to see if a retry is needed to cope
    with older kernels where the exclude guest/host perf_event_attr bits
    were not used.

    Signed-off-by: Arnaldo Carvalho de Melo

    Arnaldo Carvalho de Melo
     

16 May, 2012

12 commits


14 May, 2012

1 commit

  • …/linux-rcu into core/rcu

    Pull the v3.5 RCU tree from Paul E. McKenney:

    1) A set of improvements and fixes to the RCU_FAST_NO_HZ feature
    (with more on the way for 3.6). Posted to LKML:
    https://lkml.org/lkml/2012/4/23/324 (commits 1-3 and 5),
    https://lkml.org/lkml/2012/4/16/611 (commit 4),
    https://lkml.org/lkml/2012/4/30/390 (commit 6), and
    https://lkml.org/lkml/2012/5/4/410 (commit 7, combined with
    the other commits for the convenience of the tester).

    2) Changes to make rcu_barrier() avoid disrupting execution of CPUs
    that have no RCU callbacks. Posted to LKML:
    https://lkml.org/lkml/2012/4/23/322.

    3) A couple of commits that improve the efficiency of the interaction
    between preemptible RCU and the scheduler, these two being all
    that survived an abortive attempt to allow preemptible RCU's
    __rcu_read_lock() to be inlined. The full set was posted to
    LKML at https://lkml.org/lkml/2012/4/14/143, and the first and
    third patches of that set remain.

    4) Lai Jiangshan's algorithmic implementation of SRCU, which includes
    call_srcu() and srcu_barrier(). A major feature of this new
    implementation is that synchronize_srcu() no longer disturbs
    the execution of other CPUs. This work is based on earlier
    implementations by Peter Zijlstra and Paul E. McKenney. Posted to
    LKML: https://lkml.org/lkml/2012/2/22/82.

    5) A number of miscellaneous bug fixes and improvements which were
    posted to LKML at: https://lkml.org/lkml/2012/4/23/353 with
    subsequent updates posted to LKML.

    Signed-off-by: Ingo Molnar <mingo@kernel.org>

    Ingo Molnar
     

08 May, 2012

1 commit


06 May, 2012

1 commit

  • Currently, we'll try mounting any device who's major device number is
    UNNAMED_MAJOR as NFS root. This would happen for non-NFS devices as
    well (such as 9p devices) but it wouldn't cause any issues since
    mounting the device as NFS would fail quickly and the code proceeded to
    doing the proper mount:

    [ 101.522716] VFS: Unable to mount root fs via NFS, trying floppy.
    [ 101.534499] VFS: Mounted root (9p filesystem) on device 0:18.

    Commit 6829a048102a ("NFS: Retry mounting NFSROOT") introduced retries
    when mounting NFS root, which means that now we don't immediately fail
    and instead it takes an additional 90+ seconds until we stop retrying,
    which has revealed the issue this patch fixes.

    This meant that it would take an additional 90 seconds to boot when
    we're not using a device type which gets detected in order before NFS.

    This patch modifies the NFS type check to require device type to be
    'Root_NFS' instead of requiring the device to have an UNNAMED_MAJOR
    major. This makes boot process cleaner since we now won't go through
    the NFS mounting code at all when the device isn't an NFS root
    ("/dev/nfs").

    Signed-off-by: Sasha Levin
    Signed-off-by: Linus Torvalds

    Sasha Levin
     

05 May, 2012

2 commits

  • Now that all archs except ia64 are converted, replace the config and
    let the ia64 select CONFIG_ARCH_INIT_TASK

    Signed-off-by: Thomas Gleixner
    Link: http://lkml.kernel.org/r/20120503085035.867948914@linutronix.de

    Thomas Gleixner
     
  • All archs define init_task in the same way (except ia64, but there is
    no particular reason why ia64 cannot use the common version). Create a
    generic instance so all archs can be converted over.

    The config switch is temporary and will be removed when all archs are
    converted over.

    Signed-off-by: Thomas Gleixner
    Cc: Benjamin Herrenschmidt
    Cc: Chen Liqin
    Cc: Chris Metcalf
    Cc: Chris Zankel
    Cc: David Howells
    Cc: David S. Miller
    Cc: Geert Uytterhoeven
    Cc: Guan Xuetao
    Cc: Haavard Skinnemoen
    Cc: Hirokazu Takata
    Cc: James E.J. Bottomley
    Cc: Jesper Nilsson
    Cc: Jonas Bonn
    Cc: Mark Salter
    Cc: Martin Schwidefsky
    Cc: Heiko Carstens
    Cc: Matt Turner
    Cc: Michal Simek
    Cc: Mike Frysinger
    Cc: Paul Mundt
    Cc: Ralf Baechle
    Cc: Richard Kuo
    Cc: Richard Weinberger
    Cc: Russell King
    Cc: Yoshinori Sato
    Link: http://lkml.kernel.org/r/20120503085034.092585287@linutronix.de

    Thomas Gleixner
     

03 May, 2012

1 commit


01 May, 2012

1 commit

  • Add a 3rd arg, named "doing", to unknown-options callbacks invoked
    from parse_args(). The arg is passed as:

    "Booting kernel" from start_kernel(),
    initcall_level_names[i] from do_initcall_level(),
    mod->name from load_module(), via parse_args(), parse_one()

    parse_args() already has the "name" parameter, which is renamed to
    "doing" to better reflect current uses 1,2 above. parse_args() passes
    it to an altered parse_one(), which now passes it down into the
    unknown option handler callbacks.

    The mod->name will be needed to handle dyndbg for loadable modules,
    since params passed by modprobe are not qualified (they do not have a
    "$modname." prefix), and by the time the unknown-param callback is
    called, the module name is not otherwise available.

    Minor tweaks:

    Add param-name to parse_one's pr_debug(), current message doesnt
    identify the param being handled, add it.

    Add a pr_info to print current level and level_name of the initcall,
    and number of registered initcalls at that level. This adds 7 lines
    to dmesg output, like:

    initlevel:6=device, 172 registered initcalls

    Drop "parameters" from initcall_level_names[], its unhelpful in the
    pr_info() added above. This array is passed into parse_args() by
    do_initcall_level().

    CC: Rusty Russell
    Signed-off-by: Jim Cromie
    Acked-by: Jason Baron
    Signed-off-by: Greg Kroah-Hartman

    Jim Cromie
     

26 Apr, 2012

1 commit

  • Renaming remaining PERF_COUNTERS options into PERF_EVENTS.

    Think we can get rid of PERF_COUNTERS now.

    Signed-off-by: Robert Richter
    Signed-off-by: Peter Zijlstra
    Link: http://lkml.kernel.org/r/1333643084-26776-5-git-send-email-robert.richter@amd.com
    Signed-off-by: Ingo Molnar

    Robert Richter
     

25 Apr, 2012

3 commits

  • Commit 026cee0086f had the side-effect of dropping the '=' from
    the unknown boot arguments that are passed to init as environment
    variables. This is because parse_args() puts a NUL in the string
    where the '=' was when it passes the "param" and "val" pointers
    to the parsing subfunctions. Previously, unknown_bootoption() was
    the last parse_args() subfunction to run, and it carefully put back
    the '=' character. Now the ignore_unknown_bootoption() is the last
    one to run, and it wasn't doing the necessary repair, so the
    envp params ended up with the embedded NUL and were no longer
    seen as valid environment variables by init.

    Tested-by: Woody Suwalski
    Acked-by: Pawel Moll
    Signed-off-by: Chris Metcalf

    Chris Metcalf
     
  • Commit #0209f649 (rcu: limit rcu_node leaf-level fanout) set an upper
    limit of 16 on the leaf-level fanout for the rcu_node tree. This was
    needed to reduce lock contention that was induced by the synchronization
    of scheduling-clock interrupts, which was in turn needed to improve
    energy efficiency for moderate-sized lightly loaded servers.

    However, reducing the leaf-level fanout means that there are more
    leaf-level rcu_node structures in the tree, which in turn means that
    RCU's grace-period initialization incurs more cache misses. This is
    not a problem on moderate-sized servers with only a few tens of CPUs,
    but becomes a major source of real-time latency spikes on systems with
    many hundreds of CPUs. In addition, the workloads running on these large
    systems tend to be CPU-bound, which eliminates the energy-efficiency
    advantages of synchronizing scheduling-clock interrupts. Therefore,
    these systems need maximal values for the rcu_node leaf-level fanout.

    This commit addresses this problem by introducing a new kernel parameter
    named RCU_FANOUT_LEAF that directly controls the leaf-level fanout.
    This parameter defaults to 16 to handle the common case of a moderate
    sized lightly loaded servers, but may be set higher on larger systems.

    Reported-by: Mike Galbraith
    Reported-by: Dimitri Sivanich
    Signed-off-by: Paul E. McKenney

    Paul E. McKenney
     
  • The old text confused real-time applications with real-time threads, so
    that you pretty much needed to understand how this kernel configuration
    parameter worked to understand the help text. This commit therefore
    attempts to make the help text human-readable.

    Reported-by: Jörn Engel
    Signed-off-by: Paul E. McKenney
    Signed-off-by: Paul E. McKenney

    Paul E. McKenney
     

20 Apr, 2012

1 commit

  • Define a config variable BUILDTIME_EXTABLE_SORT to control build time
    sorting of the kernel's exception table.

    Patch Makefile to do the sorting when BUILDTIME_EXTABLE_SORT is
    selected.

    Signed-off-by: David Daney
    Link: http://lkml.kernel.org/r/1334872799-14589-4-git-send-email-ddaney.cavm@gmail.com
    Signed-off-by: H. Peter Anvin

    David Daney
     

08 Apr, 2012

1 commit

  • Make it possible to easily switch between strong mandatory
    type checks and relaxed type checks so that the code can
    easily be tested with the type checks and then built
    with the strong type checks disabled so the resulting
    code can be used.

    Require strong mandatory type checks when enabling the user namespace.
    It is very simple to make a typo and use the wrong type allowing
    conversions to/from userspace values to be bypassed by accident,
    the strong type checks prevent this.

    Acked-by: Serge Hallyn
    Signed-off-by: Eric W. Biederman

    Eric W. Biederman
     

02 Apr, 2012

1 commit

  • Pull cpumask cleanups from Rusty Russell:
    "(Somehow forgot to send this out; it's been sitting in linux-next, and
    if you don't want it, it can sit there another cycle)"

    I'm a sucker for things that actually delete lines of code.

    Fix up trivial conflict in arch/arm/kernel/kprobes.c, where Rusty fixed
    a user of &cpu_online_map to be cpu_online_mask, but that code got
    deleted by commit b21d55e98ac2 ("ARM: 7332/1: extract out code patch
    function from kprobes").

    * tag 'for-linus' of git://github.com/rustyrussell/linux:
    cpumask: remove old cpu_*_map.
    documentation: remove references to cpu_*_map.
    drivers/cpufreq/db8500-cpufreq: remove references to cpu_*_map.
    remove references to cpu_*_map in arch/

    Linus Torvalds
     

01 Apr, 2012

2 commits


29 Mar, 2012

2 commits

  • This has been obsolescent for a while, fix documentation and
    misc comments.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • …m/linux/kernel/git/dhowells/linux-asm_system

    Pull "Disintegrate and delete asm/system.h" from David Howells:
    "Here are a bunch of patches to disintegrate asm/system.h into a set of
    separate bits to relieve the problem of circular inclusion
    dependencies.

    I've built all the working defconfigs from all the arches that I can
    and made sure that they don't break.

    The reason for these patches is that I recently encountered a circular
    dependency problem that came about when I produced some patches to
    optimise get_order() by rewriting it to use ilog2().

    This uses bitops - and on the SH arch asm/bitops.h drags in
    asm-generic/get_order.h by a circuituous route involving asm/system.h.

    The main difficulty seems to be asm/system.h. It holds a number of
    low level bits with no/few dependencies that are commonly used (eg.
    memory barriers) and a number of bits with more dependencies that
    aren't used in many places (eg. switch_to()).

    These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

    Move memory barriers here. This already done for MIPS and Alpha.

    (2) asm/switch_to.h

    Move switch_to() and related stuff here.

    (3) asm/exec.h

    Move arch_align_stack() here. Other process execution related bits
    could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

    Move xchg() and cmpxchg() here as they're full word atomic ops and
    frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

    Move die() and related bits.

    (6) asm/auxvec.h

    Move AT_VECTOR_SIZE_ARCH here.

    Other arch headers are created as needed on a per-arch basis."

    Fixed up some conflicts from other header file cleanups and moving code
    around that has happened in the meantime, so David's testing is somewhat
    weakened by that. We'll find out anything that got broken and fix it..

    * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
    Delete all instances of asm/system.h
    Remove all #inclusions of asm/system.h
    Add #includes needed to permit the removal of asm/system.h
    Move all declarations of free_initmem() to linux/mm.h
    Disintegrate asm/system.h for OpenRISC
    Split arch_align_stack() out from asm-generic/system.h
    Split the switch_to() wrapper out of asm-generic/system.h
    Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
    Create asm-generic/barrier.h
    Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
    Disintegrate asm/system.h for Xtensa
    Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
    Disintegrate asm/system.h for Tile
    Disintegrate asm/system.h for Sparc
    Disintegrate asm/system.h for SH
    Disintegrate asm/system.h for Score
    Disintegrate asm/system.h for S390
    Disintegrate asm/system.h for PowerPC
    Disintegrate asm/system.h for PA-RISC
    Disintegrate asm/system.h for MN10300
    ...

    Linus Torvalds