13 Mar, 2014
1 commit
-
Commit 73f7d1ca3263 (ACPI / init: Run acpi_early_init() before
timekeeping_init()) optimistically moved the early ACPI initialization
before timekeeping_init(), but that didn't work, because it broke fast
TSC calibration for Julian Wollrath on Thinkpad x121e (and most likely
for others too). The reason is that acpi_early_init() enables the SCI
and that interferes with the fast TSC calibration mechanism.Thus follow the original idea to execute acpi_early_init() before
efi_enter_virtual_mode() to help the EFI people for now and we can
revisit the other problem that commit 73f7d1ca3263 attempted to
address in the future (if really necessary).Fixes: 73f7d1ca3263 (ACPI / init: Run acpi_early_init() before timekeeping_init())
Reported-by: Julian Wollrath
Reviewed-by: Thomas Gleixner
Signed-off-by: Rafael J. Wysocki
06 Feb, 2014
1 commit
-
This changes 'do_execve()' to get the executable name as a 'struct
filename', and to free it when it is done. This is what the normal
users want, and it simplifies and streamlines their error handling.The controlled lifetime of the executable name also fixes a
use-after-free problem with the trace_sched_process_exec tracepoint: the
lifetime of the passed-in string for kernel users was not at all
obvious, and the user-mode helper code used UMH_WAIT_EXEC to serialize
the pathname allocation lifetime with the execve() having finished,
which in turn meant that the trace point that happened after
mm_release() of the old process VM ended up using already free'd memory.To solve the kernel string lifetime issue, this simply introduces
"getname_kernel()" that works like the normal user-space getname()
function, except with the source coming from kernel memory.As Oleg points out, this also means that we could drop the tcomm[] array
from 'struct linux_binprm', since the pathname lifetime now covers
setup_new_exec(). That would be a separate cleanup.Reported-by: Igor Zhbanov
Tested-by: Steven Rostedt
Cc: Oleg Nesterov
Cc: Al Viro
Signed-off-by: Linus Torvalds
28 Jan, 2014
1 commit
-
mca_init() no longer exists.
sbus_init() is defined in arch/sparc/kernel/sbus.c and is a subsys_initcall.
both are not needed in main.c any more.Signed-off-by: Kang Hu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Jan, 2014
1 commit
-
Pull ACPI and power management updates from Rafael Wysocki:
"As far as the number of commits goes, the top spot belongs to ACPI
this time with cpufreq in the second position and a handful of PM
core, PNP and cpuidle updates. They are fixes and cleanups mostly, as
usual, with a couple of new features in the mix.The most visible change is probably that we will create struct
acpi_device objects (visible in sysfs) for all devices represented in
the ACPI tables regardless of their status and there will be a new
sysfs attribute under those objects allowing user space to check that
status via _STA.Consequently, ACPI device eject or generally hot-removal will not
delete those objects, unless the table containing the corresponding
namespace nodes is unloaded, which is extremely rare. Also ACPI
container hotplug will be handled quite a bit differently and cpufreq
will support CPU boost ("turbo") generically and not only in the
acpi-cpufreq driver.Specifics:
- ACPI core changes to make it create a struct acpi_device object for
every device represented in the ACPI tables during all namespace
scans regardless of the current status of that device. In
accordance with this, ACPI hotplug operations will not delete those
objects, unless the underlying ACPI tables go away.- On top of the above, new sysfs attribute for ACPI device objects
allowing user space to check device status by triggering the
execution of _STA for its ACPI object. From Srinivas Pandruvada.- ACPI core hotplug changes reducing code duplication, integrating
the PCI root hotplug with the core and reworking container hotplug.- ACPI core simplifications making it use ACPI_COMPANION() in the
code "glueing" ACPI device objects to "physical" devices.- ACPICA update to upstream version 20131218. This adds support for
the DBG2 and PCCT tables to ACPICA, fixes some bugs and improves
debug facilities. From Bob Moore, Lv Zheng and Betty Dall.- Init code change to carry out the early ACPI initialization
earlier. That should allow us to use ACPI during the timekeeping
initialization and possibly to simplify the EFI initialization too.
From Chun-Yi Lee.- Clenups of the inclusions of ACPI headers in many places all over
from Lv Zheng and Rashika Kheria (work in progress).- New helper for ACPI _DSM execution and rework of the code in
drivers that uses _DSM to execute it via the new helper. From
Jiang Liu.- New Win8 OSI blacklist entries from Takashi Iwai.
- Assorted ACPI fixes and cleanups from Al Stone, Emil Goode, Hanjun
Guo, Lan Tianyu, Masanari Iida, Oliver Neukum, Prarit Bhargava,
Rashika Kheria, Tang Chen, Zhang Rui.- intel_pstate driver updates, including proper Baytrail support,
from Dirk Brandewie and intel_pstate documentation from Ramkumar
Ramachandra.- Generic CPU boost ("turbo") support for cpufreq from Lukasz
Majewski.- powernow-k6 cpufreq driver fixes from Mikulas Patocka.
- cpufreq core fixes and cleanups from Viresh Kumar, Jane Li, Mark
Brown.- Assorted cpufreq drivers fixes and cleanups from Anson Huang, John
Tobias, Paul Bolle, Paul Walmsley, Sachin Kamat, Shawn Guo, Viresh
Kumar.- cpuidle cleanups from Bartlomiej Zolnierkiewicz.
- Support for hibernation APM events from Bin Shi.
- Hibernation fix to avoid bringing up nonboot CPUs with ACPI EC
disabled during thaw transitions from Bjørn Mork.- PM core fixes and cleanups from Ben Dooks, Leonardo Potenza, Ulf
Hansson.- PNP subsystem fixes and cleanups from Dmitry Torokhov, Levente
Kurusa, Rashika Kheria.- New tool for profiling system suspend from Todd E Brandt and a
cpupower tool cleanup from One Thousand Gnomes"* tag 'pm+acpi-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (153 commits)
thermal: exynos: boost: Automatic enable/disable of BOOST feature (at Exynos4412)
cpufreq: exynos4x12: Change L0 driver data to CPUFREQ_BOOST_FREQ
Documentation: cpufreq / boost: Update BOOST documentation
cpufreq: exynos: Extend Exynos cpufreq driver to support boost
cpufreq / boost: Kconfig: Support for software-managed BOOST
acpi-cpufreq: Adjust the code to use the common boost attribute
cpufreq: Add boost frequency support in core
intel_pstate: Add trace point to report internal state.
cpufreq: introduce cpufreq_generic_get() routine
ARM: SA1100: Create dummy clk_get_rate() to avoid build failures
cpufreq: stats: create sysfs entries when cpufreq_stats is a module
cpufreq: stats: free table and remove sysfs entry in a single routine
cpufreq: stats: remove hotplug notifiers
cpufreq: stats: handle cpufreq_unregister_driver() and suspend/resume properly
cpufreq: speedstep: remove unused speedstep_get_state
platform: introduce OF style 'modalias' support for platform bus
PM / tools: new tool for suspend/resume performance optimization
ACPI: fix module autoloading for ACPI enumerated devices
ACPI: add module autoloading support for ACPI enumerated devices
ACPI: fix create_modalias() return value handling
...
24 Jan, 2014
2 commits
-
Use constant format string in case message changes.
Signed-off-by: Tetsuo Handa
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Its user was removed in v2.5.2.4.
Signed-off-by: Geert Uytterhoeven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Jan, 2014
2 commits
-
Switch to memblock interfaces for early memory allocator instead of
bootmem allocator. No functional change in beahvior than what it is in
current code from bootmem users points of view.Archs already converted to NO_BOOTMEM now directly use memblock
interfaces instead of bootmem wrappers build on top of memblock. And
the archs which still uses bootmem, these new apis just fall back to
exiting bootmem APIs.Signed-off-by: Santosh Shilimkar
Cc: Yinghai Lu
Cc: Tejun Heo
Cc: "Rafael J. Wysocki"
Cc: Arnd Bergmann
Cc: Christoph Lameter
Cc: Greg Kroah-Hartman
Cc: Grygorii Strashko
Cc: H. Peter Anvin
Cc: Johannes Weiner
Cc: KAMEZAWA Hiroyuki
Cc: Konrad Rzeszutek Wilk
Cc: Michal Hocko
Cc: Paul Walmsley
Cc: Pavel Machek
Cc: Russell King
Cc: Tony Lindgren
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
is 72 bytes. For page->ptl they will be allocated from kmalloc-96 slab,
so we loose 24 on each. An average system can easily allocate few tens
thousands of page->ptl and overhead is significant.Let's create a separate slab for page->ptl allocation to solve this.
To make sure that it really works this time, some numbers from my test
machine (just booted, no load):Before:
# grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
kmalloc-96 31987 32190 128 30 1 : tunables 120 60 8 : slabdata 1073 1073 92
After:
# grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
page->ptl 27516 28143 72 53 1 : tunables 120 60 8 : slabdata 531 531 9
kmalloc-96 3853 5280 128 30 1 : tunables 120 60 8 : slabdata 176 176 0Note that the patch is useful not only for debug case, but also for
PREEMPT_RT, where spinlock_t is always bloated.Signed-off-by: Kirill A. Shutemov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Jan, 2014
1 commit
-
This is a variant patch from Rafael J. Wysocki's
ACPI / init: Run acpi_early_init() before efi_enter_virtual_mode()According to Matt Fleming, if acpi_early_init() was executed before
efi_enter_virtual_mode(), the EFI initialization could benefit from
it, so Rafael's patch makes that happen.And, we want accessing ACPI TAD device to set system clock, so move
acpi_early_init() before timekeeping_init(). This final position is
also before efi_enter_virtual_mode().Tested-by: Toshi Kani
Signed-off-by: Lee, Chun-Yi
Signed-off-by: Rafael J. Wysocki
21 Nov, 2013
1 commit
-
This reverts commit ea1e7ed33708c7a760419ff9ded0a6cb90586a50.
Al points out that while the commit *does* actually create a separate
slab for the page->ptl allocation, that slab is never actually used, and
the code continues to use kmalloc/kfree.Damien Wyart points out that the original patch did have the conversion
to use kmem_cache_alloc/free, so it got lost somewhere on its way to me.Revert the half-arsed attempt that didn't do anything. If we really do
want the special slab (remember: this is all relevant just for debug
builds, so it's not necessarily all that critical) we might as well redo
the patch fully.Reported-by: Al Viro
Acked-by: Andrew Morton
Cc: Kirill A Shutemov
Signed-off-by: Linus Torvalds
15 Nov, 2013
2 commits
-
Pull module updates from Rusty Russell:
"Mainly boring here, too. rmmod --wait finally removed, though"* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
modpost: fix bogus 'exported twice' warnings.
init: fix in-place parameter modification regression
asmlinkage, module: Make ksymtab and kcrctab symbols and __this_module __visible
kernel: add support for init_array constructors
modpost: Optionally ignore secondary errors seen if a single module build fails
module: remove rmmod --wait option. -
If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
is 72 bytes. For page->ptl they will be allocated from kmalloc-96 slab,
so we loose 24 on each. An average system can easily allocate few tens
thousands of page->ptl and overhead is significant.Let's create a separate slab for page->ptl allocation to solve this.
Signed-off-by: Kirill A. Shutemov
Cc: Peter Zijlstra
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Nov, 2013
3 commits
-
Pull networking updates from David Miller:
1) The addition of nftables. No longer will we need protocol aware
firewall filtering modules, it can all live in userspace.At the core of nftables is a, for lack of a better term, virtual
machine that executes byte codes to inspect packet or metadata
(arriving interface index, etc.) and make verdict decisions.Besides support for loading packet contents and comparing them, the
interpreter supports lookups in various datastructures as
fundamental operations. For example sets are supports, and
therefore one could create a set of whitelist IP address entries
which have ACCEPT verdicts attached to them, and use the appropriate
byte codes to do such lookups.Since the interpreted code is composed in userspace, userspace can
do things like optimize things before giving it to the kernel.Another major improvement is the capability of atomically updating
portions of the ruleset. In the existing netfilter implementation,
one has to update the entire rule set in order to make a change and
this is very expensive.Userspace tools exist to create nftables rules using existing
netfilter rule sets, but both kernel implementations will need to
co-exist for quite some time as we transition from the old to the
new stuff.Kudos to Patrick McHardy, Pablo Neira Ayuso, and others who have
worked so hard on this.2) Daniel Borkmann and Hannes Frederic Sowa made several improvements
to our pseudo-random number generator, mostly used for things like
UDP port randomization and netfitler, amongst other things.In particular the taus88 generater is updated to taus113, and test
cases are added.3) Support 64-bit rates in HTB and TBF schedulers, from Eric Dumazet
and Yang Yingliang.4) Add support for new 577xx tigon3 chips to tg3 driver, from Nithin
Sujir.5) Fix two fatal flaws in TCP dynamic right sizing, from Eric Dumazet,
Neal Cardwell, and Yuchung Cheng.6) Allow IP_TOS and IP_TTL to be specified in sendmsg() ancillary
control message data, much like other socket option attributes.
From Francesco Fusco.7) Allow applications to specify a cap on the rate computed
automatically by the kernel for pacing flows, via a new
SO_MAX_PACING_RATE socket option. From Eric Dumazet.8) Make the initial autotuned send buffer sizing in TCP more closely
reflect actual needs, from Eric Dumazet.9) Currently early socket demux only happens for TCP sockets, but we
can do it for connected UDP sockets too. Implementation from Shawn
Bohrer.10) Refactor inet socket demux with the goal of improving hash demux
performance for listening sockets. With the main goals being able
to use RCU lookups on even request sockets, and eliminating the
listening lock contention. From Eric Dumazet.11) The bonding layer has many demuxes in it's fast path, and an RCU
conversion was started back in 3.11, several changes here extend the
RCU usage to even more locations. From Ding Tianhong and Wang
Yufen, based upon suggestions by Nikolay Aleksandrov and Veaceslav
Falico.12) Allow stackability of segmentation offloads to, in particular, allow
segmentation offloading over tunnels. From Eric Dumazet.13) Significantly improve the handling of secret keys we input into the
various hash functions in the inet hashtables, TCP fast open, as
well as syncookies. From Hannes Frederic Sowa. The key fundamental
operation is "net_get_random_once()" which uses static keys.Hannes even extended this to ipv4/ipv6 fragmentation handling and
our generic flow dissector.14) The generic driver layer takes care now to set the driver data to
NULL on device removal, so it's no longer necessary for drivers to
explicitly set it to NULL any more. Many drivers have been cleaned
up in this way, from Jingoo Han.15) Add a BPF based packet scheduler classifier, from Daniel Borkmann.
16) Improve CRC32 interfaces and generic SKB checksum iterators so that
SCTP's checksumming can more cleanly be handled. Also from Daniel
Borkmann.17) Add a new PMTU discovery mode, IP_PMTUDISC_INTERFACE, which forces
using the interface MTU value. This helps avoid PMTU attacks,
particularly on DNS servers. From Hannes Frederic Sowa.18) Use generic XPS for transmit queue steering rather than internal
(re-)implementation in virtio-net. From Jason Wang.* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits)
random32: add test cases for taus113 implementation
random32: upgrade taus88 generator to taus113 from errata paper
random32: move rnd_state to linux/random.h
random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized
random32: add periodic reseeding
random32: fix off-by-one in seeding requirement
PHY: Add RTL8201CP phy_driver to realtek
xtsonic: add missing platform_set_drvdata() in xtsonic_probe()
macmace: add missing platform_set_drvdata() in mace_probe()
ethernet/arc/arc_emac: add missing platform_set_drvdata() in arc_emac_probe()
ipv6: protect for_each_sk_fl_rcu in mem_check with rcu_read_lock_bh
vlan: Implement vlan_dev_get_egress_qos_mask as an inline.
ixgbe: add warning when max_vfs is out of range.
igb: Update link modes display in ethtool
netfilter: push reasm skb through instead of original frag skbs
ip6_output: fragment outgoing reassembled skb properly
MAINTAINERS: mv643xx_eth: take over maintainership from Lennart
net_sched: tbf: support of 64bit rates
ixgbe: deleting dfwd stations out of order can cause null ptr deref
ixgbe: fix build err, num_rx_queues is only available with CONFIG_RPS
... -
This patch proposes to make init failures more explicit.
Before this, the "No init found" message didn't help much. It could
sometimes be misleading and actually mean "No *working* init found".This message could hide many different issues:
- no init program candidates found at all
- some init program candidates exist but can't be executed (missing
execute permissions, failed to load shared libraries, executable
compiled for an unknown architecture...)This patch notifies the kernel user when a candidate init program is found
but can't be executed. In each failure situation, the error code is
displayed, to quickly find the root cause. "No init found" is also
replaced by "No working init found", which is more correct.This will help embedded Linux developers (especially the newcomers),
regularly making and debugging new root filesystems.Credits to Geert Uytterhoeven and Janne Karhunen for their improvement
suggestions.Signed-off-by: Michael Opdenacker
Cc: Geert Uytterhoeven
Tested-by: Janne Karhunen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It's already available in
Signed-off-by: Geert Uytterhoeven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Oct, 2013
1 commit
-
Before commit 026cee0086fe1df4cf74691cf273062cc769617d
("params: _initcall-like kernel parameters") the __setup
parameter parsing code could modify parameter in the
static_command_line buffer and such modifications were kept. After
that commit such modifications are destroyed during per-initcall level
parameter parsing because the same static_command_line buffer is used
and only parameters for appropriate initcall level are parsed.That change broke at least parsing "ubd" parameter in the ubd driver
when the COW file is used.Now the separate buffer is used for per-initcall parameter parsing.
Signed-off-by: Krzysztof Mazur
Signed-off-by: Rusty Russell
24 Oct, 2013
1 commit
-
Conflicts:
drivers/net/usb/qmi_wwan.c
include/net/dst.hTrivial merge conflicts, both were overlapping changes.
Signed-off-by: David S. Miller
20 Oct, 2013
1 commit
-
Usage of the static key primitives to toggle a branch must not be used
before jump_label_init() is called from init/main.c. jump_label_init
reorganizes and wires up the jump_entries so usage before that could
have unforeseen consequences.Following primitives are now checked for correct use:
* static_key_slow_inc
* static_key_slow_dec
* static_key_slow_dec_deferred
* jump_label_rate_limitThe x86 architecture already checks this by testing if the default_nop
was already replaced with an optimal nop or with a branch instruction. It
will panic then. Other architectures don't check for this.Because we need to relax this check for the x86 arch to allow code to
transition from default_nop to the enabled state and other architectures
did not check for this at all this patch introduces checking on the
static_key primitives in a non-arch dependent manner.All checked functions are considered slow-path so the additional check
does no harm to performance.The warnings are best observed with earlyprintk.
Based on a patch from Andi Kleen.
Cc: Steven Rostedt
Cc: Peter Zijlstra
Cc: Andi Kleen
Signed-off-by: Hannes Frederic Sowa
Signed-off-by: David S. Miller
11 Oct, 2013
2 commits
-
Merge in asm goto fix, to be able to apply the asm/rmwcc.h fix.
Signed-off-by: Ingo Molnar
-
Pull /dev/random changes from Ted Ts'o:
"These patches are designed to enable improvements to /dev/random for
non-x86 platforms, in particular MIPS and ARM"* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: allow architectures to optionally define random_get_entropy()
random: run random_int_secret_init() run after all late_initcalls
25 Sep, 2013
1 commit
-
Replace the single preempt_count() 'function' that's an lvalue with
two proper functions:preempt_count() - returns the preempt_count value as rvalue
preempt_count_set() - Allows setting the preempt-count valueAlso provide preempt_count_ptr() as a convenience wrapper to implement
all modifying operations.Signed-off-by: Peter Zijlstra
Link: http://lkml.kernel.org/n/tip-orxrbycjozopqfhb4dxdkdvb@git.kernel.org
[ Fixed build failure. ]
Signed-off-by: Ingo Molnar
23 Sep, 2013
1 commit
-
The some platforms (e.g., ARM) initializes their clocks as
late_initcalls for some unknown reason. So make sure
random_int_secret_init() is run after all of the late_initcalls are
run.Cc: stable@vger.kernel.org
Signed-off-by: "Theodore Ts'o"
14 Aug, 2013
1 commit
-
Prepare for using a static key in the context tracking subsystem.
This will help optimizing the off case on its many users:* user_enter, user_exit, exception_enter, exception_exit, guest_enter,
guest_exit, vtime_*()Signed-off-by: Frederic Weisbecker
Cc: Steven Rostedt
Cc: Paul E. McKenney
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Borislav Petkov
Cc: Li Zhong
Cc: Mike Galbraith
Cc: Kevin Hilman
07 Jul, 2013
1 commit
-
Pull timer core updates from Thomas Gleixner:
"The timer changes contain:- posix timer code consolidation and fixes for odd corner cases
- sched_clock implementation moved from ARM to core code to avoid
duplication by other architectures- alarm timer updates
- clocksource and clockevents unregistration facilities
- clocksource/events support for new hardware
- precise nanoseconds RTC readout (Xen feature)
- generic support for Xen suspend/resume oddities
- the usual lot of fixes and cleanups all over the place
The parts which touch other areas (ARM/XEN) have been coordinated with
the relevant maintainers. Though this results in an handful of
trivial to solve merge conflicts, which we preferred over nasty cross
tree merge dependencies.The patches which have been committed in the last few days are bug
fixes plus the posix timer lot. The latter was in akpms queue and
next for quite some time; they just got forgotten and Frederic
collected them last minute."* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits)
hrtimer: Remove unused variable
hrtimers: Move SMP function call to thread context
clocksource: Reselect clocksource when watchdog validated high-res capability
posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting
posix_timers: fix racy timer delta caching on task exit
posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule()
selftests: add basic posix timers selftests
posix_cpu_timers: consolidate expired timers check
posix_cpu_timers: consolidate timer list cleanups
posix_cpu_timer: consolidate expiry time type
tick: Sanitize broadcast control logic
tick: Prevent uncontrolled switch to oneshot mode
tick: Make oneshot broadcast robust vs. CPU offlining
x86: xen: Sync the CMOS RTC as well as the Xen wallclock
x86: xen: Sync the wallclock when the system time is set
timekeeping: Indicate that clock was set in the pvclock gtod notifier
timekeeping: Pass flags instead of multiple bools to timekeeping_update()
xen: Remove clock_was_set() call in the resume path
hrtimers: Support resuming with two or more CPUs online (but stopped)
timer: Fix jiffies wrap behavior of round_jiffies_common()
...
04 Jul, 2013
1 commit
-
do_one_initcall() uses a 64 byte string buffer to save a message. This
buffer is declared static and is only used at boot up and when a module
is loaded. As 64 bytes is very small, and this function has very limited
scope, there's no reason to waste permanent memory with this string and
not just simply put it on the stack.Signed-off-by: Steven Rostedt
Cc: Geert Uytterhoeven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Jun, 2013
1 commit
-
Nothing about the sched_clock implementation in the ARM port is
specific to the architecture. Generalize the code so that other
architectures can use it by selecting GENERIC_SCHED_CLOCK.Signed-off-by: Stephen Boyd
[jstultz: Merge minor collisions with other patches in my tree]
Signed-off-by: John Stultz
28 May, 2013
1 commit
-
The current scheme of using the timer tick was fine for per-thread
events. However, it was causing bias issues in system-wide mode
(including for uncore PMUs). Event groups would not get their fair
share of runtime on the PMU. With tickless kernels, if a core is idle
there is no timer tick, and thus no event rotation (multiplexing).
However, there are events (especially uncore events) which do count
even though cores are asleep.This patch changes the timer source for multiplexing. It introduces a
per-PMU per-cpu hrtimer. The advantage is that even when a core goes
idle, it will come back to service the hrtimer, thus multiplexing on
system-wide events works much better.The per-PMU implementation (suggested by PeterZ) enables adjusting the
multiplexing interval per PMU. The preferred interval is stashed into
the struct pmu. If not set, it will be forced to the default interval
value.In order to minimize the impact of the hrtimer, it is turned on and
off on demand. When the PMU on a CPU is overcommited, the hrtimer is
activated. It is stopped when the PMU is not overcommitted.In order for this to work properly, we had to change the order of
initialization in start_kernel() such that hrtimer_init() is run
before perf_event_init().The default interval in milliseconds is set to a timer tick just like
with the old code. We will provide a sysctl to tune this in another
patch.Signed-off-by: Stephane Eranian
Signed-off-by: Peter Zijlstra
Cc: Frederic Weisbecker
Cc: Arnaldo Carvalho de Melo
Link: http://lkml.kernel.org/r/1364991694-5876-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar
06 May, 2013
1 commit
-
Pull 'full dynticks' support from Ingo Molnar:
"This tree from Frederic Weisbecker adds a new, (exciting! :-) core
kernel feature to the timer and scheduler subsystems: 'full dynticks',
or CONFIG_NO_HZ_FULL=y.This feature extends the nohz variable-size timer tick feature from
idle to busy CPUs (running at most one task) as well, potentially
reducing the number of timer interrupts significantly.This feature got motivated by real-time folks and the -rt tree, but
the general utility and motivation of full-dynticks runs wider than
that:- HPC workloads get faster: CPUs running a single task should be able
to utilize a maximum amount of CPU power. A periodic timer tick at
HZ=1000 can cause a constant overhead of up to 1.0%. This feature
removes that overhead - and speeds up the system by 0.5%-1.0% on
typical distro configs even on modern systems.- Real-time workload latency reduction: CPUs running critical tasks
should experience as little jitter as possible. The last remaining
source of kernel-related jitter was the periodic timer tick.- A single task executing on a CPU is a pretty common situation,
especially with an increasing number of cores/CPUs, so this feature
helps desktop and mobile workloads as well.The cost of the feature is mainly related to increased timer
reprogramming overhead when a CPU switches its tick period, and thus
slightly longer to-idle and from-idle latency.Configuration-wise a third mode of operation is added to the existing
two NOHZ kconfig modes:- CONFIG_HZ_PERIODIC: [formerly !CONFIG_NO_HZ], now explicitly named
as a config option. This is the traditional Linux periodic tick
design: there's a HZ tick going on all the time, regardless of
whether a CPU is idle or not.- CONFIG_NO_HZ_IDLE: [formerly CONFIG_NO_HZ=y], this turns off the
periodic tick when a CPU enters idle mode.- CONFIG_NO_HZ_FULL: this new mode, in addition to turning off the
tick when a CPU is idle, also slows the tick down to 1 Hz (one
timer interrupt per second) when only a single task is running on a
CPU.The .config behavior is compatible: existing !CONFIG_NO_HZ and
CONFIG_NO_HZ=y settings get translated to the new values, without the
user having to configure anything. CONFIG_NO_HZ_FULL is turned off by
default.This feature is based on a lot of infrastructure work that has been
steadily going upstream in the last 2-3 cycles: related RCU support
and non-periodic cputime support in particular is upstream already.This tree adds the final pieces and activates the feature. The pull
request is marked RFC because:- it's marked 64-bit only at the moment - the 32-bit support patch is
small but did not get ready in time.- it has a number of fresh commits that came in after the merge
window. The overwhelming majority of commits are from before the
merge window, but still some aspects of the tree are fresh and so I
marked it RFC.- it's a pretty wide-reaching feature with lots of effects - and
while the components have been in testing for some time, the full
combination is still not very widely used. That it's default-off
should reduce its regression abilities and obviously there are no
known regressions with CONFIG_NO_HZ_FULL=y enabled either.- the feature is not completely idempotent: there is no 100%
equivalent replacement for a periodic scheduler/timer tick. In
particular there's ongoing work to map out and reduce its effects
on scheduler load-balancing and statistics. This should not impact
correctness though, there are no known regressions related to this
feature at this point.- it's a pretty ambitious feature that with time will likely be
enabled by most Linux distros, and we'd like you to make input on
its design/implementation, if you dislike some aspect we missed.
Without flaming us to crisp! :-)Future plans:
- there's ongoing work to reduce 1Hz to 0Hz, to essentially shut off
the periodic tick altogether when there's a single busy task on a
CPU. We'd first like 1 Hz to be exposed more widely before we go
for the 0 Hz target though.- once we reach 0 Hz we can remove the periodic tick assumption from
nr_running>=2 as well, by essentially interrupting busy tasks only
as frequently as the sched_latency constraints require us to do -
once every 4-40 msecs, depending on nr_running.I am personally leaning towards biting the bullet and doing this in
v3.10, like the -rt tree this effort has been going on for too long -
but the final word is up to you as usual.More technical details can be found in Documentation/timers/NO_HZ.txt"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
sched: Keep at least 1 tick per second for active dynticks tasks
rcu: Fix full dynticks' dependency on wide RCU nocb mode
nohz: Protect smp_processor_id() in tick_nohz_task_switch()
nohz_full: Add documentation.
cputime_nsecs: use math64.h for nsec resolution conversion helpers
nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config
nohz: Reduce overhead under high-freq idling patterns
nohz: Remove full dynticks' superfluous dependency on RCU tree
nohz: Fix unavailable tick_stop tracepoint in dynticks idle
nohz: Add basic tracing
nohz: Select wide RCU nocb for full dynticks
nohz: Disable the tick when irq resume in full dynticks CPU
nohz: Re-evaluate the tick for the new task after a context switch
nohz: Prepare to stop the tick on irq exit
nohz: Implement full dynticks kick
nohz: Re-evaluate the tick from the scheduler IPI
sched: New helper to prevent from stopping the tick in full dynticks
sched: Kick full dynticks CPU that have more than one task enqueued.
perf: New helper to prevent full dynticks CPUs from stopping tick
perf: Kick full dynticks CPU if events rotation is needed
...
02 May, 2013
2 commits
-
The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.Merge a common upstream merge point that has these
updates.Conflicts:
include/linux/perf_event.h
kernel/rcutree.h
kernel/rcutree_plugin.hSigned-off-by: Frederic Weisbecker
-
Commit f91eb62f71b3 ("init: scream bloody murder if interrupts are
enabled too early") added three new warnings. The first two seemed
reasonable, but the third included a warning when an initcall returned
non-zero. Although, the third WARN() does include an imbalanced preempt
disabled, or irqs disable, it shouldn't warn if it only had an initcall
that just returns non-zero.In fact, according to Linus, it shouldn't print at all. As it only
prints with initcall_debug set, and that already shows enough
information to fix things.Link: http://lkml.kernel.org/r/CA+55aFzaBC5SFi7=F2mfm+KWY5qTsBmOqgbbs8E+LUS8JK-sBg@mail.gmail.com
Suggested-by: Linus Torvalds
Reported-by: Konrad Rzeszutek Wilk
Signed-off-by: Steven Rostedt
Signed-off-by: Linus Torvalds
30 Apr, 2013
5 commits
-
Pull core timer updates from Ingo Molnar:
"The main changes in this cycle's merge are:- Implement shadow timekeeper to shorten in kernel reader side
blocking, by Thomas Gleixner.- Posix timers enhancements by Pavel Emelyanov:
- allocate timer ID per process, so that exact timer ID allocations
can be re-created be checkpoint/restore code.- debuggability and tooling (/proc/PID/timers, etc.) improvements.
- suspend/resume enhancements by Feng Tang: on certain new Intel Atom
processors (Penwell and Cloverview), there is a feature that the
TSC won't stop in S3 state, so the TSC value won't be reset to 0
after resume. This can be taken advantage of by the generic via
the CLOCK_SOURCE_SUSPEND_NONSTOP flag: instead of using the RTC to
recover/approximate sleep time, the main (and precise) clocksource
can be used.- Fix /proc/timer_list for 4096 CPUs by Nathan Zimmer: on so many
CPUs the file goes beyond 4MB of size and thus the current
simplistic seqfile approach fails. Convert /proc/timer_list to a
proper seq_file with its own iterator.- Cleanups and refactorings of the core timekeeping code by John
Stultz.- International Atomic Clock time is managed by the NTP code
internally currently but not exposed externally. Separate the TAI
code out and add CLOCK_TAI support and TAI support to the hrtimer
and posix-timer code, by John Stultz.- Add deep idle support enhacement to the broadcast clockevents core
timer code, by Daniel Lezcano: add an opt-in CLOCK_EVT_FEAT_DYNIRQ
clockevents feature (which will be utilized by future clockevents
driver updates), which allows the use of IRQ affinities to avoid
spurious wakeups of idle CPUs - the right CPU with an expiring
timer will be woken.- Add new ARM bcm281xx clocksource driver, by Christian Daudt
- ... various other fixes and cleanups"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
clockevents: Set dummy handler on CPU_DEAD shutdown
timekeeping: Update tk->cycle_last in resume
posix-timers: Remove unused variable
clockevents: Switch into oneshot mode even if broadcast registered late
timer_list: Convert timer list to be a proper seq_file
timer_list: Split timer_list_show_tickdevices
posix-timers: Show sigevent info in proc file
posix-timers: Introduce /proc/PID/timers file
posix timers: Allocate timer id per process (v2)
timekeeping: Make sure to notify hrtimers when TAI offset changes
hrtimer: Fix ktime_add_ns() overflow on 32bit architectures
hrtimer: Add expiry time overflow check in hrtimer_interrupt
timekeeping: Shorten seq_count region
timekeeping: Implement a shadow timekeeper
timekeeping: Delay update of clock->cycle_last
timekeeping: Store cycle_last value in timekeeper struct as well
ntp: Remove ntp_lock, using the timekeeping locks to protect ntp state
timekeeping: Simplify tai updating from do_adjtimex
timekeeping: Hold timekeepering locks in do_adjtimex and hardpps
timekeeping: Move ADJ_SETOFFSET to top level do_adjtimex()
... -
Pull SMP/hotplug changes from Ingo Molnar:
"This is a pretty large, multi-arch series unifying and generalizing
the various disjunct pieces of idle routines that architectures have
historically copied from each other and have grown in random, wildly
inconsistent and sometimes buggy directions:101 files changed, 455 insertions(+), 1328 deletions(-)
this went through a number of review and test iterations before it was
committed, it was tested on various architectures, was exposed to
linux-next for quite some time - nevertheless it might cause problems
on architectures that don't read the mailing lists and don't regularly
test linux-next.This cat herding excercise was motivated by the -rt kernel, and was
brought to you by Thomas "the Whip" Gleixner."* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
idle: Remove GENERIC_IDLE_LOOP config switch
um: Use generic idle loop
ia64: Make sure interrupts enabled when we "safe_halt()"
sparc: Use generic idle loop
idle: Remove unused ARCH_HAS_DEFAULT_IDLE
bfin: Fix typo in arch_cpu_idle()
xtensa: Use generic idle loop
x86: Use generic idle loop
unicore: Use generic idle loop
tile: Use generic idle loop
tile: Enter idle with preemption disabled
sh: Use generic idle loop
score: Use generic idle loop
s390: Use generic idle loop
powerpc: Use generic idle loop
parisc: Use generic idle loop
openrisc: Use generic idle loop
mn10300: Use generic idle loop
mips: Use generic idle loop
microblaze: Use generic idle loop
... -
Also enables cleanup of some 80-col trickery.
Cc: Richard Weinberger
Cc: Uwe Kleine-König
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If the kernel was booted with the "quiet" boot option we have currently no
chance to see why an initrd fails. Change KERN_WARNING to KERN_ERR to see
what is going on.Signed-off-by: Richard Weinberger
Cc: "H. Peter Anvin"
Cc: Rusty Russell
Cc: Jim Cromie
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
As I was testing a lot of my code recently, and having several
"successes", I accidentally noticed in the dmesg this little line:start_kernel(): bug: interrupts were enabled *very* early, fixing it
Sure enough, one of my patches two commits ago enabled interrupts early.
The sad part here is that I never noticed it, and I ran several tests with
ktest too, and ktest did not notice this line.What ktest looks for (and so does many other automated testing scripts) is
a back trace produced by a WARN_ON() or BUG(). As a back trace was never
produced, my buggy patch could have slipped into linux-next, or even
worse, mainline.Adding a WARN(!irqs_disabled()) makes this bug a little more obvious:
PID hash table entries: 4096 (order: 3, 32768 bytes)
__ex_table already sorted, skipping sort
Checking aperture...
No AGP bridge found
Calgary: detecting Calgary via BIOS EBDA area
Calgary: Unable to locate Rio Grande table in EBDA - bailing!
Memory: 2003252k/2054848k available (4857k kernel code, 460k absent, 51136k reserved, 6210k data, 1096k init)
------------[ cut here ]------------
WARNING: at /home/rostedt/work/git/linux-trace.git/init/main.c:543 start_kernel+0x21e/0x415()
Hardware name: To Be Filled By O.E.M.
Interrupts were enabled *very* early, fixing it
Modules linked in:
Pid: 0, comm: swapper/0 Not tainted 3.8.0-test+ #286
Call Trace:
warn_slowpath_common+0x83/0x9b
warn_slowpath_fmt+0x46/0x48
start_kernel+0x21e/0x415
x86_64_start_reservations+0x10e/0x112
x86_64_start_kernel+0x102/0x111
---[ end trace 007d8b0491b4f5d8 ]---
Preemptible hierarchical RCU implementation.
RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
NR_IRQS:4352 nr_irqs:712 16
Console: colour VGA+ 80x25
console [ttyS0] enabled, bootconsole disabledDo you see it?
The original version of this patch just slapped a WARN_ON() in there and
kept the printk(). Ard van Breemen suggested using the WARN() interface,
which makes the code a bit cleaner.Also, while examining other warnings in init/main.c, I found two other
locations that deserve a bloody murder scream if their conditions are hit,
and updated them accordingly.Signed-off-by: Steven Rostedt
Cc: Ard van Breemen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Apr, 2013
1 commit
-
We need full dynticks CPU to also be RCU nocb so
that we don't have to keep the tick to handle RCU
callbacks.Make sure the range passed to nohz_full= boot
parameter is a subset of rcu_nocbs=The CPUs that fail to meet this requirement will be
excluded from the nohz_full range. This is checked
early in boot time, before any CPU has the opportunity
to stop its tick.Suggested-by: Steven Rostedt
Reviewed-by: Paul E. McKenney
Signed-off-by: Frederic Weisbecker
Cc: Andrew Morton
Cc: Chris Metcalf
Cc: Christoph Lameter
Cc: Geoff Levand
Cc: Gilad Ben Yossef
Cc: Hakan Akkan
Cc: Ingo Molnar
Cc: Kevin Hilman
Cc: Li Zhong
Cc: Paul E. McKenney
Cc: Paul Gortmaker
Cc: Peter Zijlstra
Cc: Steven Rostedt
Cc: Thomas Gleixner
08 Apr, 2013
1 commit
-
For now this calls cpu_idle(), but in the long run we want to move the
cpu bringup code to the core and therefor we add a state argument.Signed-off-by: Thomas Gleixner
Cc: Linus Torvalds
Cc: Rusty Russell
Cc: Paul McKenney
Cc: Peter Zijlstra
Reviewed-by: Cc: Srivatsa S. Bhat
Cc: Magnus Damm
Link: http://lkml.kernel.org/r/20130321215233.583190032@linutronix.de
Signed-off-by: Thomas Gleixner
07 Mar, 2013
1 commit
-
To convert the clockevents code to cpumask_var_t we need to move the
init call after the allocator setup.Clockevents are earliest registered from time_init() as they need
interrupts being set up, so this is safe.Signed-off-by: Thomas Gleixner
Link: http://lkml.kernel.org/r/20130306111537.304379448@linutronix.de
Cc: Rusty Russell
20 Feb, 2013
1 commit
-
Pull async changes from Tejun Heo:
"These are followups for the earlier deadlock issue involving async
ending up waiting for itself through block requesting module[1]. The
following changes are made by these commits.- Instead of requesting default elevator on each request_queue init,
block now requests it once early during boot.- Kmod triggers warning if invoked from an async worker.
- Async synchronization implementation has been reimplemented. It's
a lot simpler now."* 'for-3.9-async' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
async: initialise list heads to fix crash
async: replace list of active domains with global list of pending items
async: keep pending tasks on async_domain and remove async_pending
async: use ULLONG_MAX for infinity cookie value
async: bring sanity to the use of words domain and running
async, kmod: warn on synchronous request_module() from async workers
block: don't request module during elevator init
init, block: try to load default elevator module early during boot
31 Jan, 2013
1 commit
-
Pull x86 fixes from Peter Anvin:
"This is a collection of miscellaneous fixes, the most important one is
the fix for the Samsung laptop bricking issue (auto-blacklisting the
samsung-laptop driver); the efi_enabled() changes you see below are
prerequisites for that fix.The other issues fixed are booting on OLPC XO-1.5, an UV fix, NMI
debugging, and requiring CAP_SYS_RAWIO for MSR references, just as
with I/O port references."* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
samsung-laptop: Disable on EFI hardware
efi: Make 'efi_enabled' a function to query EFI facilities
smp: Fix SMP function call empty cpu mask race
x86/msr: Add capabilities check
x86/dma-debug: Bump PREALLOC_DMA_DEBUG_ENTRIES
x86/olpc: Fix olpc-xo1-sci.c build errors
arch/x86/platform/uv: Fix incorrect tlb flush all issue
x86-64: Fix unwind annotations in recent NMI changes
x86-32: Start out cr0 clean, disable paging before modifying cr3/4