In Linux-3.9 we removed the mwait_idle() loop:
69fb3676df ("x86 idle: remove mwait_idle() and "idle=mwait" cmdline param")
The reasoning was that modern machines should be sufficiently
happy during the boot process using the default_idle() HALT
loop, until cpuidle loads and either acpi_idle or intel_idle
invoke the newer MWAIT-with-hints idle loop.
But two machines reported problems:
1. Certain Core2-era machines support MWAIT-C1 and HALT only.
MWAIT-C1 is preferred for optimal power and performance.
But if they support just C1, cpuidle never loads and
so they use the boot-time default idle loop forever.
2. Some laptops will boot-hang if HALT is used,
but will boot successfully if MWAIT is used.
This appears to be a hidden assumption in BIOS SMI,
that is presumably valid on the proprietary OS
where the BIOS was validated.
https://bugzilla.kernel.org/show_bug.cgi?id=60770
So here we effectively revert the patch above, restoring
the mwait_idle() loop. However, we don't bother restoring
the idle=mwait cmdline parameter, since it appears to add
no value.
Maintainer notes:
For 3.9, simply revert 69fb3676df
for 3.10, patch -F3 applies, fuzz needed due to __cpuinit use in
context For 3.11, 3.12, 3.13, this patch applies cleanly
Tested-by: Mike Galbraith <bitbucket@online.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Mike Galbraith <bitbucket@online.de>
Cc: <stable@vger.kernel.org> # 3.9+
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ian Malone <ibmalone@gmail.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/345254a551eb5a6a866e048d7ab570fd2193aca4.1389763084.git.len.brown@intel.com
[ Ported to recent kernels. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds rq->clock update skip for SCHED_DEADLINE task yield,
to tell update_rq_clock() that we've just updated the clock, so that
we don't do a microscopic update in schedule() and double the
fastpath cost.
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1425961200-3809-1-git-send-email-wanpeng.li@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If the CPU is running a realtime task that does not round-robin
with another realtime task of equal priority, there is no point
in keeping the scheduler tick going. After all, whenever the
scheduler tick runs, the kernel will just decide not to
reschedule.
Extend sched_can_stop_tick() to recognize these situations, and
inform the rest of the kernel that the scheduler tick can be
stopped.
Tested-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@redhat.com
Cc: mtosatti@redhat.com
Link: http://lkml.kernel.org/r/20150216152349.6a8ed824@annuminas.surriel.com
[ Small cleanliness tweak. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 81907478c4 ("sched/fair: Avoid using uninitialized variable
in preferred_group_nid()") unconditionally initializes max_group with
NODE_MASK_NONE, this means that when !max_faults (max_group didn't get
set), we'll now continue the iteration with an empty mask.
Which in turn makes the actual body of the loop go away, so we'll just
iterate until completion; short circuit this by breaking out of the
loop as soon as this would happen.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150209113727.GS5029@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is a subtle interaction between the logic introduced in commit
e63da03639 ("sched/numa: Allow task switch if load imbalance improves"),
the way the load balancer counts the load on each NUMA node, and the way
NUMA hinting faults are done.
Specifically, the load balancer only counts currently running tasks
in the load, while NUMA hinting faults may cause tasks to stop, if
the page is locked by another task.
This could cause all of the threads of a large single instance workload,
like SPECjbb2005, to migrate to the same NUMA node. This was possible
because occasionally they all fault on the same few pages, and only one
of the threads remains runnable. That thread can move to the process's
preferred NUMA node without making the imbalance worse, because nothing
else is running at that time.
The fix is to check the direction of the net moving of load, and to
refuse a NUMA move if it would cause the system to move past the point
of balance. In an unbalanced state, only moves that bring us closer
to the balance point are allowed.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: mgorman@suse.de
Link: http://lkml.kernel.org/r/20150203165648.0e9ac692@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Setting the root group's cpu.rt_runtime_us to 0 is a bad thing; it
would disallow the kernel creating RT tasks.
One can of course still set it to 1, which will (likely) still wreck
your kernel, but at least make it clear that setting it to 0 is not
good.
Collect both sanity checks into the one place while we're there.
Suggested-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150209112715.GO24151@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Because task_group() uses a cache of autogroup_task_group(), whose
output depends on sched_class, switching classes can generate
problems.
In particular, when started as fair, the cache points to the
autogroup, so when switching to RT the tg_rt_schedulable() test fails
for every cpu.rt_{runtime,period}_us change because now the autogroup
has tasks and no runtime.
Furthermore, going back to the previous semantics of varying
task_group() with sched_class has the down-side that the sched_debug
output varies as well, even though the task really is in the
autogroup.
Therefore add an autogroup exception to tg_has_rt_tasks() -- such that
both (all) task_group() usages in sched/core now have one. And remove
all the remnants of the variable task_group() output.
Reported-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Stefan Bader <stefan.bader@canonical.com>
Fixes: 8323f26ce3 ("sched: Fix race in task_group()")
Link: http://lkml.kernel.org/r/20150209112237.GR5029@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
io_schedule() calls blk_flush_plug() which, depending on the
contents of current->plug, can initiate arbitrary blk-io requests.
Note that this contrasts with blk_schedule_flush_plug() which requires
all non-trivial work to be handed off to a separate thread.
This makes it possible for io_schedule() to recurse, and initiating
block requests could possibly call mempool_alloc() which, in times of
memory pressure, uses io_schedule().
Apart from any stack usage issues, io_schedule() will not behave
correctly when called recursively as delayacct_blkio_start() does
not allow for repeated calls.
So:
- use ->in_iowait to detect recursion. Set it earlier, and restore
it to the old value.
- move the call to "raw_rq" after the call to blk_flush_plug().
As this is some sort of per-cpu thing, we want some chance that
we are on the right CPU
- When io_schedule() is called recurively, use blk_schedule_flush_plug()
which cannot further recurse.
- as this makes io_schedule() a lot more complex and as io_schedule()
must match io_schedule_timeout(), but all the changes in io_schedule_timeout()
and make io_schedule a simple wrapper for that.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Moved the now rudimentary io_schedule() into sched.h. ]
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Link: http://lkml.kernel.org/r/20150213162600.059fffb2@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit de30ec4730 "Remove unnecessary ->wait.lock serialization when
reading completion state" was not correct, without lock/unlock the code
like stop_machine_from_inactive_cpu()
while (!completion_done())
cpu_relax();
can return before complete() finishes its spin_unlock() which writes to
this memory. And spin_unlock_wait().
While at it, change try_wait_for_completion() to use READ_ONCE().
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reported-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Added a comment with the barrier. ]
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: raghavendra.kt@linux.vnet.ibm.com
Cc: waiman.long@hp.com
Fixes: de30ec4730 ("sched/completion: Remove unnecessary ->wait.lock serialization when reading completion state")
Link: http://lkml.kernel.org/r/20150212195913.GA30430@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since the function graph tracer needs to disable preemption, it might
call preempt_schedule() after reenabling it if something triggered the
need for rescheduling in between.
Therefore we can't trace preempt_schedule() itself because we would
face a function tracing recursion otherwise as the tracer is always
called before PREEMPT_ACTIVE gets set to prevent that recursion. This is
why preempt_schedule() is tagged as "notrace".
But the same issue applies to every function called by preempt_schedule()
before PREEMPT_ACTIVE is actually set. And preempt_schedule_common() is
one such example. Unfortunately we forgot to tag it as notrace as well
and as a result we are encountering tracing recursion since it got
introduced by:
a18b5d0181 ("sched: Fix missing preemption opportunity")
Let's fix that by applying the appropriate function tag to
preempt_schedule_common().
Reported-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1424110807-15057-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A deadline task may be throttled and dequeued at the same time.
This happens, when it becomes throttled in schedule(), which
is called to go to sleep:
current->state = TASK_INTERRUPTIBLE;
schedule()
deactivate_task()
dequeue_task_dl()
update_curr_dl()
start_dl_timer()
__dequeue_task_dl()
prev->on_rq = 0;
Later the timer fires, but the task is still dequeued:
dl_task_timer()
enqueue_task_dl() /* queues on dl_rq; on_rq remains 0 */
Someone wakes it up:
try_to_wake_up()
enqueue_dl_entity()
BUG_ON(on_dl_rq())
Patch fixes this problem, it prevents queueing !on_rq tasks
on dl_rq.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Wrote comment. ]
Cc: Juri Lelli <juri.lelli@arm.com>
Fixes: 1019a359d3 ("sched/deadline: Fix stale yield state")
Link: http://lkml.kernel.org/r/1374601424090314@web4j.yandex.ru
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Kirill reported that a dl task can be throttled and dequeued at the
same time. This happens, when it becomes throttled in schedule(),
which is called to go to sleep:
current->state = TASK_INTERRUPTIBLE;
schedule()
deactivate_task()
dequeue_task_dl()
update_curr_dl()
start_dl_timer()
__dequeue_task_dl()
prev->on_rq = 0;
This invalidates the assumption from commit 0f397f2c90 ("sched/dl:
Fix race in dl_task_timer()"):
"The only reason we don't strictly need ->pi_lock now is because
we're guaranteed to have p->state == TASK_RUNNING here and are
thus free of ttwu races".
And therefore we have to use the full task_rq_lock() here.
This further amends the fact that we forgot to update the rq lock loop
for TASK_ON_RQ_MIGRATE, from commit cca26e8009 ("sched: Teach
scheduler to understand TASK_ON_RQ_MIGRATING state").
Reported-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Link: http://lkml.kernel.org/r/20150217123139.GN5029@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There was a wee bit of confusion around the exact ordering here;
clarify things.
Reported-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20150217121258.GM5029@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 mm cleanups from Ingo Molnar:
"Two cleanups: simplify parse_setup_data() and sanitize_e820_map()
usage"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, e820: Clean up sanitize_e820_map() users
x86, setup: Let early_memremap() handle page alignment
Pull x86 SoC updates from Ingo Molnar:
"Various Intel Atom SoC updates (mostly to enhance debuggability), plus
an apb_timer cleanup"
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: pmc_atom: Expose contents of PSS
x86: pmc_atom: Clean up init function
x86: pmc-atom: Remove unused macro
x86: pmc_atom: don%27t check for NULL twice
x86: pmc-atom: Assign debugfs node as soon as possible
x86/platform: Remove unused function from apb_timer.c
Pull x86 fpu updates from Ingo Molnar:
"Initial round of kernel_fpu_begin/end cleanups from Oleg Nesterov,
plus a cleanup from Borislav Petkov"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, fpu: Fix math_state_restore() race with kernel_fpu_begin()
x86, fpu: Don't abuse has_fpu in __kernel_fpu_begin/end()
x86, fpu: Introduce per-cpu in_kernel_fpu state
x86/fpu: Use a symbolic name for asm operand
Pull EFI updates from Ingo Molnar:
"Main changes:
- Move efivarfs from the misc filesystem section to pseudo filesystem
- Expose firmware platform size in sysfs
- Improve robustness of get_memory_map() by removing assumptions on
the size of efi_memory_desc_t.
- various cleanups and fixes
The biggest risk is the get_memory_map() change, which changes the way
that both the arm64 and x86 EFI boot stub build the early memory map.
There are no known regressions with it at the moment, BYMMV"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: Don't look for chosen@0 node on DT platforms
firmware: efi: Remove unneeded guid unparse
efi/libstub: Call get_memory_map() to obtain map and desc sizes
efi: Small leak on error in runtime map code
efi: rtc-efi: Mark UIE as unsupported
arm64/efi: efistub: Apply __init annotation
efi: Expose underlying UEFI firmware platform size to userland
efi: Rename efi_guid_unparse to efi_guid_to_str
efi: Update the URLs for efibootmgr
fs: Make efivarfs a pseudo filesystem, built by default with EFI
Pull x86 asm changes from Ingo Molnar:
"The main changes in this cycle were the x86/entry and sysret
enhancements from Andy Lutomirski, see merge commits 772a9aca12 and
b57c0b5175 for details"
[ Exectutive summary: IST exceptions that interrupt user space will run
on the regular kernel stack instead of the IST stack. Which
simplifies things particularly on return to user space.
The sysret cleanup ends up simplifying the logic on when we can use
sysret vs when we have to use iret. - Linus ]
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86_64, entry: Remove the syscall exit audit and schedule optimizations
x86_64, entry: Use sysret to return to userspace when possible
x86, traps: Fix ist_enter from userspace
x86, vdso: teach 'make clean' remove vdso64 binaries
x86_64 entry: Fix RCX for ptraced syscalls
x86: entry_64.S: fold SAVE_ARGS_IRQ macro into its sole user
x86: ia32entry.S: fix wrong symbolic constant usage: R11->ARGOFFSET
x86: entry_64.S: delete unused code
x86, mce: Get rid of TIF_MCE_NOTIFY and associated mce tricks
x86, traps: Add ist_begin_non_atomic and ist_end_non_atomic
x86: Clean up current_stack_pointer
x86, traps: Track entry into and exit from IST context
x86, entry: Switch stacks on a paranoid entry from userspace
Pull x86 APIC updates from Ingo Molnar:
"Continued fallout of the conversion of the x86 IRQ code to the
hierarchical irqdomain framework: more cleanups, simplifications,
memory allocation behavior enhancements, mainly in the interrupt
remapping and APIC code"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
x86, init: Fix UP boot regression on x86_64
iommu/amd: Fix irq remapping detection logic
x86/acpi: Make acpi_[un]register_gsi_ioapic() depend on CONFIG_X86_LOCAL_APIC
x86: Consolidate boot cpu timer setup
x86/apic: Reuse apic_bsp_setup() for UP APIC setup
x86/smpboot: Sanitize uniprocessor init
x86/smpboot: Move apic init code to apic.c
init: Get rid of x86isms
x86/apic: Move apic_init_uniprocessor code
x86/smpboot: Cleanup ioapic handling
x86/apic: Sanitize ioapic handling
x86/ioapic: Add proper checks to setp/enable_IO_APIC()
x86/ioapic: Provide stub functions for IOAPIC%3Dn
x86/smpboot: Move smpboot inlines to code
x86/x2apic: Use state information for disable
x86/x2apic: Split enable and setup function
x86/x2apic: Disable x2apic from nox2apic setup
x86/x2apic: Add proper state tracking
x86/x2apic: Clarify remapping mode for x2apic enablement
x86/x2apic: Move code in conditional region
...
Pull timer updates from Ingo Molnar:
"The main changes in this cycle were:
- rework hrtimer expiry calculation in hrtimer_interrupt(): the
previous code had a subtle bug where expiry caching would miss an
expiry, resulting in occasional bogus (late) expiry of hrtimers.
- continuing Y2038 fixes
- ktime division optimization
- misc smaller fixes and cleanups"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimer: Make __hrtimer_get_next_event() static
rtc: Convert rtc_set_ntp_time() to use timespec64
rtc: Remove redundant rtc_valid_tm() from rtc_hctosys()
rtc: Modify rtc_hctosys() to address y2038 issues
rtc: Update rtc-dev to use y2038-safe time interfaces
rtc: Update interface.c to use y2038-safe time interfaces
time: Expose get_monotonic_boottime64 for in-kernel use
time: Expose getboottime64 for in-kernel uses
ktime: Optimize ktime_divns for constant divisors
hrtimer: Prevent stale expiry time in hrtimer_interrupt()
ktime.h: Introduce ktime_ms_delta
Pull scheduler updates from Ingo Molnar:
"The main scheduler changes in this cycle were:
- various sched/deadline fixes and enhancements
- rescheduling latency fixes/cleanups
- rework the rq->clock code to be more consistent and more robust.
- minor micro-optimizations
- ->avg.decay_count fixes
- add a stack overflow check to might_sleep()
- idle-poll handler fix, possibly resulting in power savings
- misc smaller updates and fixes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/Documentation: Remove unneeded word
sched/wait: Introduce wait_on_bit_timeout()
sched: Pull resched loop to __schedule() callers
sched/deadline: Remove cpu_active_mask from cpudl_find()
sched: Fix hrtick_start() on UP
sched/deadline: Avoid pointless __setscheduler()
sched/deadline: Fix stale yield state
sched/deadline: Fix hrtick for a non-leftmost task
sched/deadline: Modify cpudl::free_cpus to reflect rd->online
sched/idle: Add missing checks to the exit condition of cpu_idle_poll()
sched: Fix missing preemption opportunity
sched/rt: Reduce rq lock contention by eliminating locking of non-feasible target
sched/debug: Print rq->clock_task
sched/core: Rework rq->clock update skips
sched/core: Validate rq_clock*() serialization
sched/core: Remove check of p->sched_class
sched/fair: Fix sched_entity::avg::decay_count initialization
sched/debug: Fix potential call to __ffs(0) in sched_show_task()
sched/debug: Check for stack overflow in ___might_sleep()
sched/fair: Fix the dealing with decay_count in __synchronize_entity_decay()
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- AMD range breakpoints support:
Extend breakpoint tools and core to support address range through
perf event with initial backend support for AMD extended
breakpoints.
The syntax is:
perf record -e mem:addr/len:type
For example set write breakpoint from 0x1000 to 0x1200 (0x1000 + 512)
perf record -e mem:0x1000/512:w
- event throttling/rotating fixes
- various event group handling fixes, cleanups and general paranoia
code to be more robust against bugs in the future.
- kernel stack overhead fixes
User-visible tooling side changes:
- Show precise number of samples in at the end of a 'record' session,
if processing build ids, since we will then traverse the whole
perf.data file and see all the PERF_RECORD_SAMPLE records,
otherwise stop showing the previous off-base heuristicly counted
number of "samples" (Namhyung Kim).
- Support to read compressed module from build-id cache (Namhyung
Kim)
- Enable sampling loads and stores simultaneously in 'perf mem'
(Stephane Eranian)
- 'perf diff' output improvements (Namhyung Kim)
- Fix error reporting for evsel pgfault constructor (Arnaldo Carvalho
de Melo)
Tooling side infrastructure changes:
- Cache eh/debug frame offset for dwarf unwind (Namhyung Kim)
- Support parsing parameterized events (Cody P Schafer)
- Add support for IP address formats in libtraceevent (David Ahern)
Plus other misc fixes"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
perf: Decouple unthrottling and rotating
perf: Drop module reference on event init failure
perf: Use POLLIN instead of POLL_IN for perf poll data in flag
perf: Fix put_event() ctx lock
perf: Fix move_group() order
perf: Fix event->ctx locking
perf: Add a bit of paranoia
perf symbols: Convert lseek + read to pread
perf tools: Use perf_data_file__fd() consistently
perf symbols: Support to read compressed module from build-id cache
perf evsel: Set attr.task bit for a tracking event
perf header: Set header version correctly
perf record: Show precise number of samples
perf tools: Do not use __perf_session__process_events() directly
perf callchain: Cache eh/debug frame offset for dwarf unwind
perf tools: Provide stub for missing pthread_attr_setaffinity_np
perf evsel: Don't rely on malloc working for sz 0
tools lib traceevent: Add support for IP address formats
perf ui/tui: Show fatal error message only if exists
perf tests: Fix typo in sample-parsing.c
...
Pull core locking updates from Ingo Molnar:
"The main changes are:
- mutex, completions and rtmutex micro-optimizations
- lock debugging fix
- various cleanups in the MCS and the futex code"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rtmutex: Optimize setting task running after being blocked
locking/rwsem: Use task->state helpers
sched/completion: Add lock-free checking of the blocking case
sched/completion: Remove unnecessary ->wait.lock serialization when reading completion state
locking/mutex: Explicitly mark task as running after wakeup
futex: Fix argument handling in futex_lock_pi() calls
doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants
locking/Documentation: Update code path
softirq/preempt: Add missing current->preempt_disable_ip update
locking/osq: No need for load/acquire when acquire-polling
locking/mcs: Better differentiate between MCS variants
locking/mutex: Introduce ww_mutex_set_context_slowpath()
locking/mutex: Move MCS related comments to proper location
locking/mutex: Checking the stamp is WW only
Pull RCU updates from Ingo Molnar:
"The main RCU changes in this cycle are:
- Documentation updates.
- Miscellaneous fixes.
- Preemptible-RCU fixes, including fixing an old bug in the
interaction of RCU priority boosting and CPU hotplug.
- SRCU updates.
- RCU CPU stall-warning updates.
- RCU torture-test updates"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
rcu: Initialize tiny RCU stall-warning timeouts at boot
rcu: Fix RCU CPU stall detection in tiny implementation
rcu: Add GP-kthread-starvation checks to CPU stall warnings
rcu: Make cond_resched_rcu_qs() apply to normal RCU flavors
rcu: Optionally run grace-period kthreads at real-time priority
ksoftirqd: Use new cond_resched_rcu_qs() function
ksoftirqd: Enable IRQs and call cond_resched() before poking RCU
rcutorture: Add more diagnostics in rcu_barrier() test failure case
torture: Flag console.log file to prevent holdovers from earlier runs
torture: Add "-enable-kvm -soundhw pcspk" to qemu command line
rcutorture: Handle different mpstat versions
rcutorture: Check from beginning to end of grace period
rcu: Remove redundant rcu_batches_completed() declaration
rcutorture: Drop rcu_torture_completed() and friends
rcu: Provide rcu_batches_completed_sched() for TINY_RCU
rcutorture: Use unsigned for Reader Batch computations
rcutorture: Make build-output parsing correctly flag RCU's warnings
rcu: Make _batches_completed() functions return unsigned long
rcutorture: Issue warnings on close calls due to Reader Batch blows
documentation: Fix smp typo in memory-barriers.txt
...
This has not been a busy release for the regulator framework, though we
do have the first parts of some ongoing work from Bjorn Andersson to
allow us to support more complex modern systems with dynamic
configuration of regulators in suspend and idle states.
- Support for device-specific properties on regulator nodes when using
simplified DT parsing in the core from Krzysztof Kozlowski.
- Restructuring of the load tracking code, intended to support future
improvements in this area for more complex system designs.
- New drivers for Maxim MAX77843 and Mediatek MT6397.
- Lots of smaller fixes and improvements.
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Merge tag 'regulator-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator updates from Mark Brown:
"This has not been a busy release for the regulator framework, though
we do have the first parts of some ongoing work from Bjorn Andersson
to allow us to support more complex modern systems with dynamic
configuration of regulators in suspend and idle states.
- Support for device-specific properties on regulator nodes when
using simplified DT parsing in the core from Krzysztof Kozlowski.
- Restructuring of the load tracking code, intended to support future
improvements in this area for more complex system designs.
- New drivers for Maxim MAX77843 and Mediatek MT6397.
- Lots of smaller fixes and improvements"
* tag 'regulator-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (29 commits)
regulator: max77843: Add max77843 regulator driver
regulator: Fix build breakage on !REGULATOR
regulator: Build sysfs entries with static attribute groups
regulator: qcom-rpm: Make it possible to specify supply
regulator: core: Consolidate drms update handling
regulator: qcom-rpm: signedness bug in probe()
regulator: da9211: Add gpio control for enable/disable of buck
regulator: qcom_rpm: Don't update vreg->uV/mV if rpm_reg_write fails
regulator: lp872x: Remove **regulators from struct lp872x
regulator: da9211: fix unmatched of_node
regulator: Update documentation after renaming function argument
regulator: axp20x: Migrate to regulator core's simplified DT parsing code
regulator: axp20x: Fill regulators_node and of_match descriptor fields
regulator: pfuze100-regulator: add pfuze3000 support
regulator: max77686: Document gpio properties
regulator: Allow parsing custom properties when using simplified DT parsing
regulator: max77686: Add GPIO control
regulator: Copy config passed during registration
regulator: tps65023: Constify struct regmap_config and regulator_ops
regulator: max8649: Constify struct regmap_config and regulator_ops
...
The major highlight this release is a refactoring of the core to allow
us to run synchronous transfers in the context of the caller when there
is no contention for the bus. This improves performance in the very
common case by eliminating context switches and reducing the number of
hardware setup and teardown operations we need to perform.
Other changes:
- New drivers for DLN-2 USB-SPI adapter and ST SPI controllers.
- A big round of cleanups, performance and feature improvements
for the xilinx driver from Ricardo Ribalda Delgado.
- A wide range of smaller cleanups, fixes and feature improvements
throughout the subsystem.
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Merge tag 'spi-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi updates from Mark Brown:
"The major highlight this release is a refactoring of the core to allow
us to run synchronous transfers in the context of the caller when
there is no contention for the bus. This improves performance in the
very common case by eliminating context switches and reducing the
number of hardware setup and teardown operations we need to perform.
Other changes:
- New drivers for DLN-2 USB-SPI adapter and ST SPI controllers.
- A big round of cleanups, performance and feature improvements for
the xilinx driver from Ricardo Ribalda Delgado.
- A wide range of smaller cleanups, fixes and feature improvements
throughout the subsystem"
* tag 'spi-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (68 commits)
spi: mxs: cleanup wait_for_completion return handling
spi: ti-qspi: cleanup wait_for_completion return handling
spi: spi-imx: cleanup wait_for_completion handling
spi: sh-msiof: cleanup wait_for_completion return handling
spi: match var type to return type of wait_for_completion
spi: spi-pxa2xx: only include mach/dma.h for legacy DMA
spi: atmel: cleanup wait_for_completion return handling
spi: fsl-dspi: Remove possible memory leak of 'chip'
spi: sh-msiof: Update calculation of frequency dividing
spi: spidev: Convert buf pointers for 32-bit compat SPI_IOC_MESSAGE(n)
spi/xilinx: Fix access invalid memory on xilinx_spi_tx
spi: Revert "spi/xilinx: Remove iowrite/ioread wrappers"
spi/xilinx: Check number of slaves range
spi/xilinx: Use polling mode on small transfers
spi/xilinx: Remove remaining_words driver data variable
spi/xilinx: Remove iowrite/ioread wrappers
spi/xilinx: Convert bits_per_word in bytes_per_word
spi/xilinx: Convert remainding_bytes in remaining words
spi/xilinx: Make spi_tx and spi_rx simmetric
spi/xilinx: Remove rx_fn and tx_fn pointer
...
A very quiet release for regmap this time around:
- Fix an endianness issue for I2C devices connected via SMBus where
we were getting two layers both trying to do endianness handling.
- Use a union to reduce the size of the regmap struct.
- A couple of smaller fixes.
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Merge tag 'regmap-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Pull regmap updates from Mark Brown:
"A very quiet release for regmap this time around:
- Fix an endianness issue for I2C devices connected via SMBus where
we were getting two layers both trying to do endianness handling.
- Use a union to reduce the size of the regmap struct.
- A couple of smaller fixes"
* tag 'regmap-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: Fix i2c word access when using SMBus access functions
regmap: Export regmap_get_val_endian
regmap: ac97: Clean up indentation
regmap: correct the description of structure element in reg_field
regmap: Move spinlock_flags into the union
Minor improvements, cleanup and fixes in various drivers
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Merge tag 'hwmon-for-linus-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon updates from Guenter Roeck:
"Explicit support for ina231 added to ina2xx driver.
Minor improvements, cleanup and fixes in various drivers"
* tag 'hwmon-for-linus-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (tmp102) add hibernation callbacks
hwmon: (ads2828) Only keep data in device data structure if needed
hwmon: (ads2828) Convert to use regmap
hwmon: (jc42) Allow negative hysteresis temperatures
hwmon: (adc128d818) Do proper sign extension
hwmon: (ad7314) Do proper sign extension
hwmon: (abx500) Fix format string warnings
hwmon: (jc42) Fix integer overflow when writing hysteresis value
hwmon: (jc42) Fix integer overflow
hwmon: (jc42) Use sign_extend32 for sign extension
hwmon: (ina2xx) Add ina231 compatible string
hwmon: (ina2xx) use DIV_ROUND_CLOSEST() to avoid rounding errors
hwmon: (ina2xx) remove an unnecessary dev_get_drvdata() result check
hwmon: (ina2xx) implement update_interval attribute for ina226
hwmon: (ina2xx) make shunt resistance configurable at run-time
hwmon: (ina2xx) don't accept shunt values greater than the calibration factor
hwmon: (ina2xx) remove a stray new line
hwmon: (ina2xx) reinitialize the chip in case it's been reset
hwmon: (nct7802) Constify struct regmap_config
There was a bad typo in commit 43759d4f42 ("random: use an improved
fast_mix() function") and I didn't notice because it "looked right", so
I saw what I expected to see when I reviewed it.
Only months later did I look and notice it's not the Threefish-inspired
mix function that I had designed and optimized.
Mea Culpa. Each input bit still has a chance to affect each output bit,
and the fast pool is spilled *long* before it fills, so it's not a total
disaster, but it's definitely not the intended great improvement.
I'm still working on finding better rotation constants. These are good
enough, but since it's unrolled twice, it's possible to get better
mixing for free by using eight different constants rather than repeating
the same four.
Signed-off-by: George Spelvin <linux@horizon.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
out a real bug. During suspend and resume the tlb_flush tracepoint is
called when the CPU is going offline. As the CPU has been noted as offline,
RCU is ignoring that CPU, which means that it can not use RCU protected
locks. When tracepoints are activated, they require RCU locking, and
if RCU is ignoring a CPU that runs a tracepoint, there is a chance that
the tracepoint could cause corruption.
The solution was to change the tracepoint into a TRACE_EVENT_CONDITION()
which allows us to check a condition to determine if the tracepoint
should be called or not. If the condition is not met, the rcu protected
code will not be executed. By adding the condition
"cpu_online(smp_processor_id())", this will prevent the RCU protected
code from being executed if the CPU is marked offline.
After adding this, another bug was discovered. As RCU checks rcu callers,
if a rcu call is not done, there is no check (obviously). We found that
tracepoints could be added in RCU ignored locations and not have lockdep
complain until the tracepoint is activated. This missed places where
tracepoints were added in places they should not have been. To fix this,
code was added in 3.18 that if lockdep is enabled, any tracepoint will
still call the rcu checks even if the tracepoint is not enabled. The bug
here, is that the check does not take the CONDITION into account. As the
condition may prevent tracepoints from being activated in RCU ignored
areas (as the one patch does), we get false positives when we enable
lockdep and hit a tracepoint that the condition prevents it from being
called in a RCU ignored location. The fix for this is to add the
CONDITION to the rcu checks, even if the tracepoint is not enabled.
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Merge tag 'trace-fixes-v3.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace fixes from Steven Rostedt:
"During testing Sedat Dilek hit a "suspicious RCU usage" splat that
pointed out a real bug. During suspend and resume the tlb_flush
tracepoint is called when the CPU is going offline. As the CPU has
been noted as offline, RCU is ignoring that CPU, which means that it
can not use RCU protected locks. When tracepoints are activated, they
require RCU locking, and if RCU is ignoring a CPU that runs a
tracepoint, there is a chance that the tracepoint could cause
corruption.
The solution was to change the tracepoint into a
TRACE_EVENT_CONDITION() which allows us to check a condition to
determine if the tracepoint should be called or not. If the condition
is not met, the rcu protected code will not be executed. By adding
the condition "cpu_online(smp_processor_id())", this will prevent the
RCU protected code from being executed if the CPU is marked offline.
After adding this, another bug was discovered. As RCU checks rcu
callers, if a rcu call is not done, there is no check (obviously). We
found that tracepoints could be added in RCU ignored locations and not
have lockdep complain until the tracepoint is activated. This missed
places where tracepoints were added in places they should not have
been. To fix this, code was added in 3.18 that if lockdep is enabled,
any tracepoint will still call the rcu checks even if the tracepoint
is not enabled. The bug here, is that the check does not take the
CONDITION into account. As the condition may prevent tracepoints from
being activated in RCU ignored areas (as the one patch does), we get
false positives when we enable lockdep and hit a tracepoint that the
condition prevents it from being called in a RCU ignored location.
The fix for this is to add the CONDITION to the rcu checks, even if
the tracepoint is not enabled"
* tag 'trace-fixes-v3.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
x86/tlb/trace: Do not trace on CPU that is offline
tracing: Add condition check to RCU lockdep checks
A couple of driver specific fixes:
- Disable DMA mode for i.MX6DL chips due to a hardware bug.
- Don't use devm_kzalloc() outside of bind/unbind paths in the fsl-dspi
driver, fixing memory leaks.
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Merge tag 'spi-v3.19-rc7' into spi-linus
spi: Fixes for v3.19
A couple of driver specific fixes:
- Disable DMA mode for i.MX6DL chips due to a hardware bug.
- Don't use devm_kzalloc() outside of bind/unbind paths in the fsl-dspi
driver, fixing memory leaks.
# gpg: Signature made Thu 05 Feb 2015 05:06:57 HKT using RSA key ID 5D5487D0
# gpg: WARNING: digest algorithm MD5 is deprecated
# gpg: please see http://www.gnupg.org/faq/weak-digest-algos.html for more information
# gpg: Oops: keyid_from_fingerprint: no pubkey
# gpg: key AF88CD16: no public key for trusted key - skipped
# gpg: key AF88CD16 marked as ultimately trusted
# gpg: key 5621E907: no public key for trusted key - skipped
# gpg: key 5621E907 marked as ultimately trusted
# gpg: Good signature from "Mark Brown <broonie@sirena.org.uk>"
# gpg: aka "Mark Brown <broonie@debian.org>"
# gpg: aka "Mark Brown <broonie@kernel.org>"
# gpg: aka "Mark Brown <broonie@tardis.ed.ac.uk>"
# gpg: aka "Mark Brown <broonie@linaro.org>"
# gpg: aka "Mark Brown <Mark.Brown@linaro.org>"
