15 Jul, 2013
1 commit
-
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.This removes all the uses of the __cpuinit macros from C files in
the core kernel directories (kernel, init, lib, mm, and include)
that don't really have a specific maintainer.[1] https://lkml.org/lkml/2013/5/20/589
Signed-off-by: Paul Gortmaker
13 Jun, 2013
1 commit
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There are instances in the kernel where we would like to disable CPU
hotplug (from sysfs) during some important operation. Today the freezer
code depends on this and the code to do it was kinda tailor-made for
that.Restructure the code and make it generic enough to be useful for other
usecases too.Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Robin Holt
Cc: H. Peter Anvin
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Russ Anderson
Cc: Robin Holt
Cc: Russell King
Cc: Guan Xuetao
Cc: Shawn Guo
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Feb, 2013
1 commit
-
Pull preparatory smp/hotplug patches from Ingo Molnar:
"Some early preparatory changes for the WIP hotplug rework by Thomas
Gleixner."* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
stop_machine: Use smpboot threads
stop_machine: Store task reference in a separate per cpu variable
smpboot: Allow selfparking per cpu threads
14 Feb, 2013
1 commit
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Use the smpboot thread infrastructure. Mark the stopper thread
selfparking and park it after it has finished the take_cpu_down()
work.Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Rusty Russell
Cc: Paul McKenney
Cc: Srivatsa S. Bhat
Cc: Arjan van de Veen
Cc: Paul Turner
Cc: Richard Weinberger
Cc: Magnus Damm
Link: http://lkml.kernel.org/r/20130131120741.686315164@linutronix.de
Signed-off-by: Thomas Gleixner
28 Jan, 2013
1 commit
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This is in preparation for the full dynticks feature. While
remotely reading the cputime of a task running in a full
dynticks CPU, we'll need to do some extra-computation. This
way we can account the time it spent tickless in userspace
since its last cputime snapshot.Signed-off-by: Frederic Weisbecker
Cc: Andrew Morton
Cc: Ingo Molnar
Cc: Li Zhong
Cc: Namhyung Kim
Cc: Paul E. McKenney
Cc: Paul Gortmaker
Cc: Peter Zijlstra
Cc: Steven Rostedt
Cc: Thomas Gleixner
12 Dec, 2012
1 commit
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Pull x86 BSP hotplug changes from Ingo Molnar:
"This tree enables CPU#0 (the boot processor) to be onlined/offlined on
x86, just like any other CPU. Enabled on Intel CPUs for now.Allowing this required the identification and fixing of latent CPU#0
assumptions (such as CPU#0 initializations, etc.) in the x86
architecture code, plus the identification of barriers to
BSP-offlining, such as active PIC interrupts which can only be
serviced on the BSP.It's behind a default-off option, and there's a debug option that
allows the automatic testing of this feature.The motivation of this feature is to allow and prepare for true
CPU-hotplug hardware support: recent changes to MCE support enable us
to detect a deteriorating but not yet hard-failing L1/L2 cache on a
CPU that could be soft-unplugged - or a failing L3 cache on a
multi-socket system.Note that true hardware hot-plug is not yet fully enabled by this,
because that requires a special platform wakeup sequence to be sent to
the freshly powered up CPU#0. Future patches for this are planned,
once such a platform exists. Chicken and egg"* 'x86-bsp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, topology: Debug CPU0 hotplug
x86/i387.c: Initialize thread xstate only on CPU0 only once
x86, hotplug: Handle retrigger irq by the first available CPU
x86, hotplug: The first online processor saves the MTRR state
x86, hotplug: During CPU0 online, enable x2apic, set_numa_node.
x86, hotplug: Wake up CPU0 via NMI instead of INIT, SIPI, SIPI
x86-32, hotplug: Add start_cpu0() entry point to head_32.S
x86-64, hotplug: Add start_cpu0() entry point to head_64.S
kernel/cpu.c: Add comment for priority in cpu_hotplug_pm_callback
x86, hotplug, suspend: Online CPU0 for suspend or hibernate
x86, hotplug: Support functions for CPU0 online/offline
x86, topology: Don't offline CPU0 if any PIC irq can not be migrated out of it
x86, Kconfig: Add config switch for CPU0 hotplug
doc: Add x86 CPU0 online/offline feature
15 Nov, 2012
2 commits
-
Even if acpi_processor_handle_eject() offlines cpu, there is a chance
to online the cpu after that. So the patch closes the window by using
get/put_online_cpus().Why does the patch change _cpu_up() logic?
The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
does not change it, there is the following race.hot-remove cpu | _cpu_up()
------------------------------------- ------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
call put_online_cpus() |
| start and continue _cpu_up()
return acpi_processor_remove() |
continue hot-remove the cpu |So _cpu_up() can continue to itself. And hot-remove cpu can also continue
itself. If the patch changes _cpu_up() logic, the race disappears as below:hot-remove cpu | _cpu_up()
-----------------------------------------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
cpu's cpu_present is set |
to false by set_cpu_present()|
call put_online_cpus() |
| start _cpu_up()
| check cpu_present() and return -EINVAL
return acpi_processor_remove() |
continue hot-remove the cpu |Signed-off-by: Yasuaki Ishimatsu
Reviewed-by: Srivatsa S. Bhat
Reviewed-by: Toshi Kani
Signed-off-by: Rafael J. Wysocki -
cpu_hotplug_pm_callback should have higher priority than
bsp_pm_callback which depends on cpu_hotplug_pm_callback to disable cpu hotplug
to avoid race during bsp online checking.This is to hightlight the priorities between the two callbacks in case people
may overlook the order.Ideally the priorities should be defined in macro/enum instead of fixed values.
To do that, a seperate patchset may be pushed which will touch serveral other
generic files and is out of scope of this patchset.Signed-off-by: Fenghua Yu
Link: http://lkml.kernel.org/r/1352835171-3958-7-git-send-email-fenghua.yu@intel.com
Reviewed-by: Srivatsa S. Bhat
Acked-by: Rafael J. Wysocki
Signed-off-by: H. Peter Anvin
09 Oct, 2012
1 commit
-
The synchronization between CPU hotplug readers and writers is achieved
by means of refcounting, safeguarded by the cpu_hotplug.lock.get_online_cpus() increments the refcount, whereas put_online_cpus()
decrements it. If we ever hit an imbalance between the two, we end up
compromising the guarantees of the hotplug synchronization i.e, for
example, an extra call to put_online_cpus() can end up allowing a
hotplug reader to execute concurrently with a hotplug writer.So, add a WARN_ON() in put_online_cpus() to detect such cases where the
refcount can go negative, and also attempt to fix it up, so that we can
continue to run.Signed-off-by: Srivatsa S. Bhat
Reviewed-by: Yasuaki Ishimatsu
Cc: Jiri Kosina
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Oct, 2012
1 commit
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Pull x86/asm changes from Ingo Molnar:
"The one change that stands out is the alternatives patching change
that prevents us from ever patching back instructions from SMP to UP:
this simplifies things and speeds up CPU hotplug.Other than that it's smaller fixes, cleanups and improvements."
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Unspaghettize do_trap()
x86_64: Work around old GAS bug
x86: Use REP BSF unconditionally
x86: Prefer TZCNT over BFS
x86/64: Adjust types of temporaries used by ffs()/fls()/fls64()
x86: Drop unnecessary kernel_eflags variable on 64-bit
x86/smp: Don't ever patch back to UP if we unplug cpus
23 Aug, 2012
1 commit
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We still patch SMP instructions to UP variants if we boot with a
single CPU, but not at any other time. In particular, not if we
unplug CPUs to return to a single cpu.Paul McKenney points out:
mean offline overhead is 6251/48=130.2 milliseconds.
If I remove the alternatives_smp_switch() from the offline
path [...] the mean offline overhead is 550/42=13.1 millisecondsBasically, we're never going to get those 120ms back, and the
code is pretty messy.We get rid of:
1) The "smp-alt-once" boot option. It's actually "smp-alt-boot", the
documentation is wrong. It's now the default.2) The skip_smp_alternatives flag used by suspend.
3) arch_disable_nonboot_cpus_begin() and arch_disable_nonboot_cpus_end()
which were only used to set this one flag.Signed-off-by: Rusty Russell
Cc: Paul McKenney
Cc: Suresh Siddha
Cc: Linus Torvalds
Cc: Andrew Morton
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/87vcgwwive.fsf@rustcorp.com.au
Signed-off-by: Ingo Molnar
13 Aug, 2012
1 commit
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Provide a generic interface for setting up and tearing down percpu
threads.On registration the threads for already online cpus are created and
started. On deregistration (modules) the threads are stoppped.During hotplug operations the threads are created, started, parked and
unparked. The datastructure for registration provides a pointer to
percpu storage space and optional setup, cleanup, park, unpark
functions. These functions are called when the thread state changes.Each implementation has to provide a function which is queried and
returns whether the thread should run and the thread function itself.The core code handles all state transitions and avoids duplicated code
in the call sites.[ paulmck: Preemption leak fix ]
Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Reviewed-by: Srivatsa S. Bhat
Cc: Rusty Russell
Reviewed-by: Paul E. McKenney
Cc: Namhyung Kim
Link: http://lkml.kernel.org/r/20120716103948.352501068@linutronix.de
Signed-off-by: Thomas Gleixner
01 Aug, 2012
1 commit
-
When hotadd_new_pgdat() is called to create new pgdat for a new node, a
fallback zonelist should be created for the new node. There's code to try
to achieve that in hotadd_new_pgdat() as below:/*
* The node we allocated has no zone fallback lists. For avoiding
* to access not-initialized zonelist, build here.
*/
mutex_lock(&zonelists_mutex);
build_all_zonelists(pgdat, NULL);
mutex_unlock(&zonelists_mutex);But it doesn't work as expected. When hotadd_new_pgdat() is called, the
new node is still in offline state because node_set_online(nid) hasn't
been called yet. And build_all_zonelists() only builds zonelists for
online nodes as:for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);build_zonelists(pgdat);
build_zonelist_cache(pgdat);
}Though we hope to create zonelist for the new pgdat, but it doesn't. So
add a new parameter "pgdat" the build_all_zonelists() to build pgdat for
the new pgdat too.Signed-off-by: Jiang Liu
Signed-off-by: Xishi Qiu
Cc: Mel Gorman
Cc: Michal Hocko
Cc: Minchan Kim
Cc: Rusty Russell
Cc: Yinghai Lu
Cc: Tony Luck
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: David Rientjes
Cc: Keping Chen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Jun, 2012
2 commits
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Add more comments on clear_tasks_mm_cpumask, plus adds a runtime check:
the function is only suitable for offlined CPUs, and if called
inappropriately, the kernel should scream aloud.[akpm@linux-foundation.org: tweak comment: s/walks up/walks/, use 80 cols]
Suggested-by: Andrew Morton
Suggested-by: Peter Zijlstra
Signed-off-by: Anton Vorontsov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Many architectures clear tasks' mm_cpumask like this:
read_lock(&tasklist_lock);
for_each_process(p) {
if (p->mm)
cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
}
read_unlock(&tasklist_lock);Depending on the context, the code above may have several problems,
such as:1. Working with task->mm w/o getting mm or grabing the task lock is
dangerous as ->mm might disappear (exit_mm() assigns NULL under
task_lock(), so tasklist lock is not enough).2. Checking for process->mm is not enough because process' main
thread may exit or detach its mm via use_mm(), but other threads
may still have a valid mm.This patch implements a small helper function that does things
correctly, i.e.:1. We take the task's lock while whe handle its mm (we can't use
get_task_mm()/mmput() pair as mmput() might sleep);2. To catch exited main thread case, we use find_lock_task_mm(),
which walks up all threads and returns an appropriate task
(with task lock held).Also, Per Peter Zijlstra's idea, now we don't grab tasklist_lock in
the new helper, instead we take the rcu read lock. We can do this
because the function is called after the cpu is taken down and marked
offline, so no new tasks will get this cpu set in their mm mask.Signed-off-by: Anton Vorontsov
Cc: Richard Weinberger
Cc: Oleg Nesterov
Cc: Peter Zijlstra
Cc: Russell King
Cc: Benjamin Herrenschmidt
Cc: Mike Frysinger
Cc: Paul Mundt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 May, 2012
1 commit
-
percpu areas are already allocated during boot for each possible cpu.
percpu idle threads can be considered as an extension of the percpu areas,
and allocate them for each possible cpu during boot.This will eliminate the need for workqueue based idle thread allocation.
In future we can move the idle thread area into the percpu area too.[ tglx: Moved the loop into smpboot.c and added an error check when
the init code failed to allocate an idle thread for a cpu which
should be onlined ]Signed-off-by: Suresh Siddha
Cc: Peter Zijlstra
Cc: Rusty Russell
Cc: Paul E. McKenney
Cc: Srivatsa S. Bhat
Cc: Tejun Heo
Cc: David Rientjes
Cc: venki@google.com
Link: http://lkml.kernel.org/r/1334966930.28674.245.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Thomas Gleixner
26 Apr, 2012
3 commits
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All SMP architectures have magic to fork the idle task and to store it
for reusage when cpu hotplug is enabled. Provide a generic
infrastructure for it.Create/reinit the idle thread for the cpu which is brought up in the
generic code and hand the thread pointer to the architecture code via
__cpu_up().Note, that fork_idle() is called via a workqueue, because this
guarantees that the idle thread does not get a reference to a user
space VM. This can happen when the boot process did not bring up all
possible cpus and a later cpu_up() is initiated via the sysfs
interface. In that case fork_idle() would be called in the context of
the user space task and take a reference on the user space VM.Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Rusty Russell
Cc: Paul E. McKenney
Cc: Srivatsa S. Bhat
Cc: Matt Turner
Cc: Russell King
Cc: Mike Frysinger
Cc: Jesper Nilsson
Cc: Richard Kuo
Cc: Tony Luck
Cc: Hirokazu Takata
Cc: Ralf Baechle
Cc: David Howells
Cc: James E.J. Bottomley
Cc: Benjamin Herrenschmidt
Cc: Martin Schwidefsky
Cc: Paul Mundt
Cc: David S. Miller
Cc: Chris Metcalf
Cc: Richard Weinberger
Cc: x86@kernel.org
Acked-by: Venkatesh Pallipadi
Link: http://lkml.kernel.org/r/20120420124557.102478630@linutronix.de -
Start a new file, which will hold SMP and CPU hotplug related generic
infrastructure.Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Rusty Russell
Cc: Paul E. McKenney
Cc: Srivatsa S. Bhat
Cc: Matt Turner
Cc: Russell King
Cc: Mike Frysinger
Cc: Jesper Nilsson
Cc: Richard Kuo
Cc: Tony Luck
Cc: Hirokazu Takata
Cc: Ralf Baechle
Cc: David Howells
Cc: James E.J. Bottomley
Cc: Benjamin Herrenschmidt
Cc: Martin Schwidefsky
Cc: Paul Mundt
Cc: David S. Miller
Cc: Chris Metcalf
Cc: Richard Weinberger
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124557.035417523@linutronix.de -
Preparatory patch to make the idle thread allocation for secondary
cpus generic.Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Rusty Russell
Cc: Paul E. McKenney
Cc: Srivatsa S. Bhat
Cc: Matt Turner
Cc: Russell King
Cc: Mike Frysinger
Cc: Jesper Nilsson
Cc: Richard Kuo
Cc: Tony Luck
Cc: Hirokazu Takata
Cc: Ralf Baechle
Cc: David Howells
Cc: James E.J. Bottomley
Cc: Benjamin Herrenschmidt
Cc: Martin Schwidefsky
Cc: Paul Mundt
Cc: David S. Miller
Cc: Chris Metcalf
Cc: Richard Weinberger
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124556.964170564@linutronix.de
09 Jan, 2012
1 commit
-
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
PM / Hibernate: Implement compat_ioctl for /dev/snapshot
PM / Freezer: fix return value of freezable_schedule_timeout_killable()
PM / shmobile: Allow the A4R domain to be turned off at run time
PM / input / touchscreen: Make st1232 use device PM QoS constraints
PM / QoS: Introduce dev_pm_qos_add_ancestor_request()
PM / shmobile: Remove the stay_on flag from SH7372's PM domains
PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume
PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode
PM: Drop generic_subsys_pm_ops
PM / Sleep: Remove forward-only callbacks from AMBA bus type
PM / Sleep: Remove forward-only callbacks from platform bus type
PM: Run the driver callback directly if the subsystem one is not there
PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
PM / Sleep: Merge internal functions in generic_ops.c
PM / Sleep: Simplify generic system suspend callbacks
PM / Hibernate: Remove deprecated hibernation snapshot ioctls
PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
ARM: S3C64XX: Implement basic power domain support
PM / shmobile: Use common always on power domain governor
...Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused
XBT_FORCE_SLEEP bit
07 Jan, 2012
1 commit
-
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
sched/tracing: Add a new tracepoint for sleeptime
sched: Disable scheduler warnings during oopses
sched: Fix cgroup movement of waking process
sched: Fix cgroup movement of newly created process
sched: Fix cgroup movement of forking process
sched: Remove cfs bandwidth period check in tg_set_cfs_period()
sched: Fix load-balance lock-breaking
sched: Replace all_pinned with a generic flags field
sched: Only queue remote wakeups when crossing cache boundaries
sched: Add missing rcu_dereference() around ->real_parent usage
[S390] fix cputime overflow in uptime_proc_show
[S390] cputime: add sparse checking and cleanup
sched: Mark parent and real_parent as __rcu
sched, nohz: Fix missing RCU read lock
sched, nohz: Set the NOHZ_BALANCE_KICK flag for idle load balancer
sched, nohz: Fix the idle cpu check in nohz_idle_balance
sched: Use jump_labels for sched_feat
sched/accounting: Fix parameter passing in task_group_account_field
sched/accounting: Fix user/system tick double accounting
sched/accounting: Re-use scheduler statistics for the root cgroup
...Fix up conflicts in
- arch/ia64/include/asm/cputime.h, include/asm-generic/cputime.h
usecs_to_cputime64() vs the sparse cleanups
- kernel/sched/fair.c, kernel/time/tick-sched.c
scheduler changes in multiple branches
15 Dec, 2011
1 commit
-
Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.Signed-off-by: Martin Schwidefsky
13 Dec, 2011
1 commit
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Building rcutorture as a module requires cpu_up() as well as cpu_down()
exported, so apply EXPORT_SYMBOL_GPL().Signed-off-by: Paul E. McKenney
Signed-off-by: Paul E. McKenney
24 Nov, 2011
1 commit
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Add __init for functions alloc_frozen_cpus() and cpu_hotplug_pm_sync_init()
because they are only called during boot time.Add static for function cpu_hotplug_pm_sync_init() because its scope is limited
in this file only.Signed-off-by: Fenghua Yu
Acked-by: Srivatsa S. Bhat
Signed-off-by: Rafael J. Wysocki
07 Nov, 2011
1 commit
-
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include
net: sch_generic remove redundant use of
net: inet_timewait_sock doesnt need
...Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
05 Nov, 2011
1 commit
-
The CPU hotplug notifications sent out by the _cpu_up() and _cpu_down()
functions depend on the value of the 'tasks_frozen' argument passed to them
(which indicates whether tasks have been frozen or not).
(Examples for such CPU hotplug notifications: CPU_ONLINE, CPU_ONLINE_FROZEN,
CPU_DEAD, CPU_DEAD_FROZEN).Thus, it is essential that while the callbacks for those notifications are
running, the state of the system with respect to the tasks being frozen or
not remains unchanged, *throughout that duration*. Hence there is a need for
synchronizing the CPU hotplug code with the freezer subsystem.Since the freezer is involved only in the Suspend/Hibernate call paths, this
patch hooks the CPU hotplug code to the suspend/hibernate notifiers
PM_[SUSPEND|HIBERNATE]_PREPARE and PM_POST_[SUSPEND|HIBERNATE] to prevent
the race between CPU hotplug and freezer, thus ensuring that CPU hotplug
notifications will always be run with the state of the system really being
what the notifications indicate, _throughout_ their execution time.Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Rafael J. Wysocki
31 Oct, 2011
1 commit
-
The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else. Revector them
onto the isolated export header for faster compile times.Nothing to see here but a whole lot of instances of:
-#include
+#includeThis commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.Signed-off-by: Paul Gortmaker
31 Mar, 2011
1 commit
-
Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
23 Mar, 2011
1 commit
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Change the printk() calls to have the KERN_INFO/KERN_ERROR stuff, and
fixes other coding style errors. Not _all_ of them are gone, though.[akpm@linux-foundation.org: revert the bits I disagree with]
Signed-off-by: Michael Rodriguez
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Jan, 2011
1 commit
-
…-linus', 'x86-paravirt-for-linus', 'core-locking-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, suspend: Avoid unnecessary smp alternatives switch during suspend/resume* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-64, asm: Use fxsaveq/fxrestorq in more places* 'x86-hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hwmon: Add core threshold notification to therm_throt.c* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, paravirt: Use native_halt on a halt, not native_safe_halt* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
locking, lockdep: Convert sprintf_symbol to %pS* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
irq: Better struct irqaction layout
14 Dec, 2010
1 commit
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During suspend, we disable all the non boot cpus. And during resume we bring
them all back again. So no need to do alternatives_smp_switch() in between.On my core 2 based laptop, this speeds up the suspend path by 15msec and the
resume path by 5 msec (suspend/resume speed up differences can be attributed
to the different P-states that the cpu is in during suspend/resume).Signed-off-by: Suresh Siddha
LKML-Reference:
Cc: Rafael J. Wysocki
Signed-off-by: H. Peter Anvin
23 Nov, 2010
2 commits
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Oleg mentioned that there is no actual guarantee the dying cpu's
migration thread is actually finished running when we get there, so
replace the BUG_ON() with a spinloop waiting for it.Reported-by: Oleg Nesterov
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
GCC warns us about:
kernel/cpu.c: In function ‘take_cpu_down’:
kernel/cpu.c:200:15: warning: unused variable ‘cpu’This variable is unused since param->hcpu is directly
used later on in cpu_notify.Signed-off-by: Dhaval Giani
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar
18 Nov, 2010
1 commit
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While discussing the need for sched_idle_next(), Oleg remarked that
since try_to_wake_up() ensures sleeping tasks will end up running on a
sane cpu, we can do away with migrate_live_tasks().If we then extend the existing hack of migrating current from
CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the
need for the sched_idle_next() abomination disappears as well, since
idle will be the only possible thread left after the migration thread
stops.This greatly simplifies the hot-unplug task migration path, as can be
seen from the resulting code reduction (and about half the new lines
are comments).Suggested-by: Oleg Nesterov
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar
09 Jun, 2010
1 commit
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Currently, when a cpu goes down, cpu_active is cleared before
CPU_DOWN_PREPARE starts and cpuset configuration is updated from a
default priority cpu notifier. When a cpu is coming up, it's set
before CPU_ONLINE but cpuset configuration again is updated from the
same cpu notifier.For cpu notifiers, this presents an inconsistent state. Threads which
a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be
migrated to other cpus because the cpu is no more inactive.Fix it by updating cpu_active in the highest priority cpu notifier and
cpuset configuration in the second highest when a cpu is coming up.
Down path is updated similarly. This guarantees that all other cpu
notifiers see consistent cpu_active and cpuset configuration.cpuset_track_online_cpus() notifier is converted to
cpuset_update_active_cpus() which just updates the configuration and
now called from cpuset_cpu_[in]active() notifiers registered from
sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus()
degenerates into partition_sched_domains() making separate notifier
for !CONFIG_CPUSETS unnecessary.This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug
callback creates a kthread and kthread_bind()s it to the target cpu,
and the thread is expected to run on that cpu.* Ingo's test discovered __cpuinit/exit markups were incorrect.
Fixed.Signed-off-by: Tejun Heo
Acked-by: Peter Zijlstra
Cc: Rusty Russell
Cc: Ingo Molnar
Cc: Paul Menage
02 Jun, 2010
1 commit
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In commit e9fb7631ebcd ("cpu-hotplug: introduce cpu_notify(),
__cpu_notify(), cpu_notify_nofail()") the new helper functions access
cpu_chain. As a result, it shouldn't be marked __cpuinitdata (via
section mismatch warning).Alternatively, the helper functions should be forced inline, or marked
__ref or __cpuinit. In the meantime, this patch silences the warning
the trivial way.Signed-off-by: Daniel J Blueman
Signed-off-by: Linus Torvalds
31 May, 2010
1 commit
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If there's only one CPU online when disable_nonboot_cpus() is called,
the error variable will not be initialized and that may lead to
erroneous behavior. Fix this issue by initializing error in
disable_nonboot_cpus() as appropriate.Signed-off-by: Rafael J. Wysocki
Signed-off-by: Linus Torvalds
28 May, 2010
3 commits
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Commit e9fb7631ebcd ("cpu-hotplug: introduce cpu_notify(),
__cpu_notify(), cpu_notify_nofail()") also introduced this annoying
warning:kernel/cpu.c:157: warning: 'cpu_notify_nofail' defined but not used
when CONFIG_HOTPLUG_CPU wasn't set.
So move that helper inside the #ifdef CONFIG_HOTPLUG_CPU region, and
simplify it while at it.Signed-off-by: Linus Torvalds
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Since when CONFIG_HOTPLUG_CPU=n, get_online_cpus() do nothing, so we don't
need cpu_hotplug_begin() either.This patch moves cpu_hotplug_begin()/cpu_hotplug_done() into the code
block of CONFIG_HOTPLUG_CPU=y.Signed-off-by: Lai Jiangshan
Cc: Gautham R Shenoy
Cc: Ingo MolnarSigned-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, onlining or offlining a CPU failure by one of the cpu notifiers
error always cause -EINVAL error. (i.e. writing 0 or 1 to
/sys/devices/system/cpu/cpuX/online gets EINVAL)To get better error reporting rather than always getting -EINVAL, This
changes cpu_notify() to return -errno value with notifier_to_errno() and
fix the callers. Now that cpu notifiers can return encapsulate errno
value.Currently, all cpu hotplug notifiers return NOTIFY_OK, NOTIFY_BAD, or
NOTIFY_DONE. So cpu_notify() can returns 0 or -EPERM with this change for
now.(notifier_to_errno(NOTIFY_OK) == 0, notifier_to_errno(NOTIFY_DONE) == 0,
notifier_to_errno(NOTIFY_BAD) == -EPERM)Forthcoming patches convert several cpu notifiers to return encapsulate
errno value with notifier_from_errno().Signed-off-by: Akinobu Mita
Cc: Rusty Russell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
