20 Apr, 2011
1 commit
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…l/git/tip/linux-2.6-tip
* 'timer-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
RTC: rtc-omap: Fix a leak of the IRQ during init failure
posix clocks: Replace mutex with reader/writer semaphore
19 Apr, 2011
1 commit
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next_pidmap() just quietly accepted whatever 'last' pid that was passed
in, which is not all that safe when one of the users is /proc.Admittedly the proc code should do some sanity checking on the range
(and that will be the next commit), but that doesn't mean that the
helper functions should just do that pidmap pointer arithmetic without
checking the range of its arguments.So clamp 'last' to PID_MAX_LIMIT. The fact that we then do "last+1"
doesn't really matter, the for-loop does check against the end of the
pidmap array properly (it's only the actual pointer arithmetic overflow
case we need to worry about, and going one bit beyond isn't going to
overflow).[ Use PID_MAX_LIMIT rather than pid_max as per Eric Biederman ]
Reported-by: Tavis Ormandy
Analyzed-by: Robert Święcki
Cc: Eric W. Biederman
Cc: Pavel Emelyanov
Signed-off-by: Linus Torvalds
18 Apr, 2011
1 commit
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A dynamic posix clock is protected from asynchronous removal by a mutex.
However, using a mutex has the unwanted effect that a long running clock
operation in one process will unnecessarily block other processes.For example, one process might call read() to get an external time stamp
coming in at one pulse per second. A second process calling clock_gettime
would have to wait for almost a whole second.This patch fixes the issue by using a reader/writer semaphore instead of
a mutex.Signed-off-by: Richard Cochran
Cc: John Stultz
Link: http://lkml.kernel.org/r/%3C20110330132421.GA31771%40riccoc20.at.omicron.at%3E
Signed-off-by: Thomas Gleixner
17 Apr, 2011
2 commits
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* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: make unplug timer trace event correspond to the schedule() unplug
block: let io_schedule() flush the plug inline -
…linus', 'timer-fixes-for-linus' and 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Set FLAGS_HAS_TIMEOUT during futex_wait restart setup* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf_event: Fix cgrp event scheduling bug in perf_enable_on_exec()
perf: Fix a build error with some GCC versions* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix erroneous all_pinned logic
sched: Fix sched-domain avg_load calculation* 'timer-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
RTC: rtc-mrst: follow on to the change of rtc_device_register()
RTC: add missing "return 0" in new alarm func for rtc-bfin.c
RTC: Fix s3c compile error due to missing s3c_rtc_setpie
RTC: Fix early irqs caused by calling rtc_set_alarm too early* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, amd: Disable GartTlbWlkErr when BIOS forgets it
x86, NUMA: Fix fakenuma boot failure
x86/mrst: Fix boot crash caused by incorrect pin to irq mapping
x86/ce4100: Add reg property to bridges
16 Apr, 2011
2 commits
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It's a pretty close match to what we had before - the timer triggering
would mean that nobody unplugged the plug in due time, in the new
scheme this matches very closely what the schedule() unplug now is.
It's essentially the difference between an explicit unplug (IO unplug)
or an implicit unplug (timer unplug, we scheduled with pending IO
queued).Signed-off-by: Jens Axboe
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Linus correctly observes that the most important dispatch cases
are now done from kblockd, this isn't ideal for latency reasons.
The original reason for switching dispatches out-of-line was to
avoid too deep a stack, so by _only_ letting the "accidental"
flush directly in schedule() be guarded by offload to kblockd,
we should be able to get the best of both worlds.So add a blk_schedule_flush_plug() that offloads to kblockd,
and only use that from the schedule() path.Signed-off-by: Jens Axboe
15 Apr, 2011
2 commits
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* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: only force kblockd unplugging from the schedule() path
block: cleanup the block plug helper functions
block, blk-sysfs: Use the variable directly instead of a function call
block: move queue run on unplug to kblockd
block: kill queue_sync_plugs()
block: readd plug trace event
block: add callback function for unplug notification
block: add comment on why we save and disable interrupts in flush_plug_list()
block: fixup block IO unplug trace call
block: remove block_unplug_timer() trace point
block: splice plug list to local context -
The FLAGS_HAS_TIMEOUT flag was not getting set, causing the restart_block to
restart futex_wait() without a timeout after a signal.Commit b41277dc7a18ee332d in 2.6.38 introduced the regression by accidentally
removing the the FLAGS_HAS_TIMEOUT assignment from futex_wait() during the setup
of the restart block. Restore the originaly behavior.Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=32922
Reported-by: Tim Smith
Reported-by: Torsten Hilbrich
Signed-off-by: Darren Hart
Signed-off-by: Eric Dumazet
Cc: Peter Zijlstra
Cc: John Kacur
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/%3Cdaac0eb3af607f72b9a4d3126b2ba8fb5ed3b883.1302820917.git.dvhart%40linux.intel.com%3E
Signed-off-by: Thomas Gleixner
13 Apr, 2011
1 commit
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We really only want to unplug the pending IO when the process actually
goes to sleep. So move the test for flushing the plug up to the place
where we actually deactivate the task - where we have properly checked
for preemption and for the process really sleeping.Acked-by: Jens Axboe
Acked-by: Peter Zijlstra
Signed-off-by: Linus Torvalds
12 Apr, 2011
4 commits
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It was removed with the on-stack plugging, readd it and track the
depth of requests added when flushing the plug.Signed-off-by: Jens Axboe
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We no longer have an unplug timer running, so no point in keeping
the trace point.Signed-off-by: Jens Axboe
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Make XEN_SAVE_RESTORE select HIBERNATE_CALLBACKS.
Remove XEN_SAVE_RESTORE dependency from PM_SLEEP.Signed-off-by: Shriram Rajagopalan
Acked-by: Ian Campbell
Signed-off-by: Rafael J. Wysocki -
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose. However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation. Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.Signed-off-by: Rafael J. Wysocki
Tested-by: Shriram Rajagopalan
11 Apr, 2011
3 commits
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The scheduler load balancer has specific code to deal with cases of
unbalanced system due to lots of unmovable tasks (for example because of
hard CPU affinity). In those situation, it excludes the busiest CPU that
has pinned tasks for load balance consideration such that it can perform
second 2nd load balance pass on the rest of the system.This all works as designed if there is only one cgroup in the system.
However, when we have multiple cgroups, this logic has false positives and
triggers multiple load balance passes despite there are actually no pinned
tasks at all.The reason it has false positives is that the all pinned logic is deep in
the lowest function of can_migrate_task() and is too low level:load_balance_fair() iterates each task group and calls balance_tasks() to
migrate target load. Along the way, balance_tasks() will also set a
all_pinned variable. Given that task-groups are iterated, this all_pinned
variable is essentially the status of last group in the scanning process.
Task group can have number of reasons that no load being migrated, none
due to cpu affinity. However, this status bit is being propagated back up
to the higher level load_balance(), which incorrectly think that no tasks
were moved. It kick off the all pinned logic and start multiple passes
attempt to move load onto puller CPU.To fix this, move the all_pinned aggregation up at the iterator level.
This ensures that the status is aggregated over all task-groups, not just
last one in the list.Signed-off-by: Ken Chen
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra
Link: http://lkml.kernel.org/r/BANLkTi=ernzNawaR5tJZEsV_QVnfxqXmsQ@mail.gmail.com
Signed-off-by: Ingo Molnar -
In function find_busiest_group(), the sched-domain avg_load isn't
calculated at all if there is a group imbalance within the domain. This
will cause erroneous imbalance calculation.The reason is that calculate_imbalance() sees sds->avg_load = 0 and it
will dump entire sds->max_load into imbalance variable, which is used
later on to migrate entire load from busiest CPU to the puller CPU.This has two really bad effect:
1. stampede of task migration, and they won't be able to break out
of the bad state because of positive feedback loop: large load
delta -> heavier load migration -> larger imbalance and the cycle
goes on.2. severe imbalance in CPU queue depth. This causes really long
scheduling latency blip which affects badly on application that
has tight latency requirement.The fix is to have kernel calculate domain avg_load in both cases. This
will ensure that imbalance calculation is always sensible and the target
is usually half way between busiest and puller CPU.Signed-off-by: Ken Chen
Signed-off-by: Peter Zijlstra
Cc:
Link: http://lkml.kernel.org/r/20110408002322.3A0D812217F@elm.corp.google.com
Signed-off-by: Ingo Molnar -
There is a bug in perf_event_enable_on_exec() when cgroup events are
active on a CPU: the cgroup events may be scheduled twice causing event
state corruptions which eventually may lead to kernel panics.The reason is that the function needs to first schedule out the cgroup
events, just like for the per-thread events. The cgroup event are
scheduled back in automatically from the perf_event_context_sched_in()
function.The patch also adds a WARN_ON_ONCE() is perf_cgroup_switch() to catch any
bogus state.Signed-off-by: Stephane Eranian
Signed-off-by: Peter Zijlstra
Link: http://lkml.kernel.org/r/20110406005454.GA1062@quad
Signed-off-by: Ingo Molnar
09 Apr, 2011
1 commit
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Fix erroneous syscall kernel-doc comments in kernel/signal.c.
Reported-by: Matt Fleming
Signed-off-by: Randy Dunlap
Signed-off-by: Linus Torvalds
08 Apr, 2011
2 commits
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…-linus', 'irq-fixes-for-linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-32, fpu: Fix FPU exception handling on non-SSE systems
x86, hibernate: Initialize mmu_cr4_features during boot
x86-32, NUMA: Fix ACPI NUMA init broken by recent x86-64 change
x86: visws: Fixup irq overhaul fallout* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Clean up rebalance_domains() load-balance interval calculation* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/mrst/vrtc: Fix boot crash in mrst_rtc_init()
rtc, x86/mrst/vrtc: Fix boot crash in rtc_read_alarm()* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: Fix cpumask leak in __setup_irq()* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf probe: Fix listing incorrect line number with inline function
perf probe: Fix to find recursively inlined function
perf probe: Fix multiple --vars options behavior
perf probe: Fix to remove redundant close
perf probe: Fix to ensure function declared file -
* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6:
Fix common misspellings
05 Apr, 2011
3 commits
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Instead of the possible multiple-evaluation of num_online_cpus()
in rebalance_domains() that Linus reported, avoid it altogether
in the normal case since it's implemented with a Hamming weight
function over a cpu bitmask which can be darn expensive for those
with big iron.This also makes it cleaner, smaller and documents the code.
Reported-by: Linus Torvalds
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
Add kernel-doc to syscalls in signal.c.
Signed-off-by: Randy Dunlap
Signed-off-by: Linus Torvalds -
General coding style and comment fixes; no code changes:
- Use multi-line-comment coding style.
- Put some function signatures completely on one line.
- Hyphenate some words.
- Spell Posix as POSIX.
- Correct typos & spellos in some comments.
- Drop trailing whitespace.
- End sentences with periods.Signed-off-by: Randy Dunlap
Signed-off-by: Linus Torvalds
04 Apr, 2011
3 commits
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…l/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix rebalance interval calculation
sched, doc: Beef up load balancing description
sched: Leave sched_setscheduler() earlier if possible, do not disturb SCHED_FIFO tasks -
…/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Fix task_struct reference leak
perf: Fix task context scheduling
perf: mmap 512 kiB by default
perf: Rebase max unprivileged mlock threshold on top of page size
perf tools: Fix NO_NEWT=1 python build error
perf symbols: Properly align symbol_conf.priv_size
perf tools: Emit clearer message for sys_perf_event_open ENOENT return
perf tools: Fixup exit path when not able to open events
perf symbols: Fix vsyscall symbol lookup
oprofile, x86: Allow setting EDGE/INV/CMASK for counter events -
The ADJ_SETOFFSET bit added in commit 094aa188 ("ntp: Add ADJ_SETOFFSET
mode bit") also introduced a way for any user to change the system time.
Sneaky or buggy calls to adjtimex() could setADJ_OFFSET_SS_READ | ADJ_SETOFFSET
which would result in a successful call to timekeeping_inject_offset().
This patch fixes the issue by adding the capability check.Signed-off-by: Richard Cochran
Signed-off-by: Linus Torvalds
03 Apr, 2011
1 commit
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The allocated cpumask should be freed in __setup_irq().
Signed-off-by: Xiaotian Feng
LKML-Reference:
Signed-off-by: Thomas Gleixner
01 Apr, 2011
1 commit
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On ppc64 the crashkernel region almost always overlaps an area of firmware.
This works fine except when using the sysfs interface to reduce the kdump
region. If we free the firmware area we are guaranteed to crash.Rename free_reserved_phys_range to crash_free_reserved_phys_range and make
it a weak function so we can override it.Signed-off-by: Anton Blanchard
Signed-off-by: Benjamin Herrenschmidt
31 Mar, 2011
5 commits
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Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
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sys_perf_event_open() had an imbalance in the number of task refs it
took causing memory leakageCc: Jiri Olsa
Cc: Oleg Nesterov
Cc: stable@kernel.org # .37+
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
Ensure we allow 512 kiB + 1 page for user control without
assuming a 4096 bytes page size.Reported-by: Peter Zijlstra
Signed-off-by: Frederic Weisbecker
Signed-off-by: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Paul Mackerras
Cc: Stephane Eranian
Cc:
LKML-Reference:
Signed-off-by: Ingo Molnar -
The interval for checking scheduling domains if they are due to be
balanced currently depends on boot state NR_CPUS, which may not
accurately reflect the number of online CPUs at the time of check.Thus replace NR_CPUS with num_online_cpus().
(ed: Should only affect those who set NR_CPUS really high, such as 4096
or so :-)Signed-off-by: Sisir Koppaka
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
sched_setscheduler() (in sched.c) is called in order of changing the
scheduling policy and/or the real-time priority of a task. Thus,
if we find out that neither of those are actually being modified, it
is possible to return earlier and save the overhead of a full
deactivate+activate cycle of the task in question.Beside that, if we have more than one SCHED_FIFO task with the same
priority on the same rq (which means they share the same priority queue)
having one of them changing its position in the priority queue because of
a sched_setscheduler (as it happens by means of the deactivate+activate)
that does not actually change the priority violates POSIX which states,
for SCHED_FIFO:"If a thread whose policy or priority has been modified by
pthread_setschedprio() is a running thread or is runnable, the effect on
its position in the thread list depends on the direction of the
modification, as follows: a. b. If the priority is unchanged, the
thread does not change position in the thread list. c. "http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_08.html
(ed: And the POSIX specification here does, briefly and somewhat unexpectedly,
match what common sense tells us as well. )Signed-off-by: Dario Faggioli
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar
30 Mar, 2011
2 commits
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Signed-off-by: Thomas Gleixner
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Reported-by: michael@ellerman.id.au
Signed-off-by: Thomas Gleixner
Cc: linuxppc-dev@lists.ozlabs.org
29 Mar, 2011
5 commits
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All users converted to new interface.
Signed-off-by: Thomas Gleixner
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Signed-off-by: Thomas Gleixner
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The only subtle difference is that alpha uses ACTUAL_NR_IRQS and
prints the IRQF_DISABLED flag.Change the generic implementation to deal with ACTUAL_NR_IRQS if
defined.The IRQF_DISABLED printing is pointless, as we nowadays run all
interrupts with irqs disabled.Signed-off-by: Thomas Gleixner
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The late night fixup missed to convert the data type from irq_desc to
irq_data, which results in a harmless but annoying warning.Signed-off-by: Thomas Gleixner
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…rnel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
vlynq: Convert irq functions* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq; Fix cleanup fallout
genirq: Fix typo and remove unused variable
genirq: Fix new kernel-doc warnings
genirq: Add setter for AFFINITY_SET in irq_data state
genirq: Provide setter inline for IRQD_IRQ_INPROGRESS
genirq: Remove handle_IRQ_event
arm: Ns9xxx: Remove private irq flow handler
powerpc: cell: Use the core flow handler
genirq: Provide edge_eoi flow handler
genirq: Move INPROGRESS, MASKED and DISABLED state flags to irq_data
genirq: Split irq_set_affinity() so it can be called with lock held.
genirq: Add chip flag for restricting cpu_on/offline calls
genirq: Add chip hooks for taking CPUs on/off line.
genirq: Add irq disabled flag to irq_data state
genirq: Reserve the irq when calling irq_set_chip()