Actually a nice symmetric startup/teardown pair which fits properly into
the state machine concept. In the long run we should be able to invoke
the startup callback for the boot CPU via the state machine and get
rid of the init function which invokes it on the boot CPU.
Note: This comes actually before the perf hardware callbacks. In the notifier
model the hardware callbacks have a higher priority than the core
callback. But that's solely for CPU offline so that hardware migration of
events happens before the core is notified about the outgoing CPU.
With the symetric state array model we have the following ordering:
UP: core -> hardware
DOWN: hardware -> core
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153333.587514098@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull ACPI fixes from Rafael Wysocki:
"All of these fix recent regressions in ACPICA, in the ACPI PCI IRQ
management code and in the ACPI AML debugger.
Specifics:
- Fix a lock ordering issue in ACPICA introduced by a recent commit
that attempted to fix a deadlock in the dynamic table loading code
which in turn appeared after changes related to the handling of
module-level AML also made in this cycle (Lv Zheng).
- Fix a recent regression in the ACPI IRQ management code that may
cause PCI drivers to be unable to register an IRQ if that IRQ
happens to be shared with a device on the ISA bus, like the
parallel port, by reverting one commit entirely and restoring the
previous behavior in two other places (Sinan Kaya).
- Fix a recent regression in the ACPI AML debugger introduced by the
commit that removed incorrect usage of IS_ERR_VALUE() from multiple
places (Lv Zheng)"
* tag 'acpi-4.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / debugger: Fix regression introduced by IS_ERR_VALUE() removal
ACPICA: Namespace: Fix namespace/interpreter lock ordering
ACPI,PCI,IRQ: separate ISA penalty calculation
Revert "ACPI, PCI, IRQ: remove redundant code in acpi_irq_penalty_init()"
ACPI,PCI,IRQ: factor in PCI possible
Pull the clockevents/clocksource tree from Daniel Lezcano:
- Convert the clocksource-probe init functions to return a value in order to
prepare the consolidation of the drivers using the DT. It is a big patchset
but went through 01.org (kbuild bot), linux next and kernel-ci (continuous
integration) (Daniel Lezcano)
- Fix a bad error handling by returning the right value for cadence_ttc
(Christophe Jaillet)
- Fix typo in the Kconfig for the Samsung pwm (Alexandre Belloni)
- Change functions to static for armada-370-xp and digicolor (Ben Dooks)
- Add support for the rk3399 SoC timer by adding bindings and a slight
change in the base address. Take the opportunity to add the DYNIRQ flag
(Huang Tao)
- Fix endian accessors for the Samsung pwm timer (Matthew Leach)
- Add Oxford Semiconductor RPS Dual Timer driver (Neil Armstrong)
- Add a kernel parameter to swich on/off the event stream feature of the arch
arm timer (Will Deacon)
The current timer wheel has some drawbacks:
1) Cascading:
Cascading can be an unbound operation and is completely pointless in most
cases because the vast majority of the timer wheel timers are canceled or
rearmed before expiration. (They are used as timeout safeguards, not as
real timers to measure time.)
2) No fast lookup of the next expiring timer:
In NOHZ scenarios the first timer soft interrupt after a long NOHZ period
must fast forward the base time to the current value of jiffies. As we
have no way to find the next expiring timer fast, the code loops linearly
and increments the base time one by one and checks for expired timers
in each step. This causes unbound overhead spikes exactly in the moment
when we should wake up as fast as possible.
After a thorough analysis of real world data gathered on laptops,
workstations, webservers and other machines (thanks Chris!) I came to the
conclusion that the current 'classic' timer wheel implementation can be
modified to address the above issues.
The vast majority of timer wheel timers is canceled or rearmed before
expiry. Most of them are timeouts for networking and other I/O tasks. The
nature of timeouts is to catch the exception from normal operation (TCP ack
timed out, disk does not respond, etc.). For these kinds of timeouts the
accuracy of the timeout is not really a concern. Timeouts are very often
approximate worst-case values and in case the timeout fires, we already
waited for a long time and performance is down the drain already.
The few timers which actually expire can be split into two categories:
1) Short expiry times which expect halfways accurate expiry
2) Long term expiry times are inaccurate today already due to the
batching which is done for NOHZ automatically and also via the
set_timer_slack() API.
So for long term expiry timers we can avoid the cascading property and just
leave them in the less granular outer wheels until expiry or
cancelation. Timers which are armed with a timeout larger than the wheel
capacity are no longer cascaded. We expire them with the longest possible
timeout (6+ days). We have not observed such timeouts in our data collection,
but at least we handle them, applying the rule of the least surprise.
To avoid extending the wheel levels for HZ=1000 so we can accomodate the
longest observed timeouts (5 days in the network conntrack code) we reduce the
first level granularity on HZ=1000 to 4ms, which effectively is the same as
the HZ=250 behaviour. From our data analysis there is nothing which relies on
that 1ms granularity and as a side effect we get better batching and timer
locality for the networking code as well.
Contrary to the classic wheel the granularity of the next wheel is not the
capacity of the first wheel. The granularities of the wheels are in the
currently chosen setting 8 times the granularity of the previous wheel.
So for HZ=250 we end up with the following granularity levels:
Level Offset Granularity Range
0 0 4 ms 0 ms - 252 ms
1 64 32 ms 256 ms - 2044 ms (256ms - ~2s)
2 128 256 ms 2048 ms - 16380 ms (~2s - ~16s)
3 192 2048 ms (~2s) 16384 ms - 131068 ms (~16s - ~2m)
4 256 16384 ms (~16s) 131072 ms - 1048572 ms (~2m - ~17m)
5 320 131072 ms (~2m) 1048576 ms - 8388604 ms (~17m - ~2h)
6 384 1048576 ms (~17m) 8388608 ms - 67108863 ms (~2h - ~18h)
7 448 8388608 ms (~2h) 67108864 ms - 536870911 ms (~18h - ~6d)
That's a worst case inaccuracy of 12.5% for the timers which are queued at the
beginning of a level.
So the new wheel concept addresses the old issues:
1) Cascading is avoided completely
2) By keeping the timers in the bucket until expiry/cancelation we can track
the buckets which have timers enqueued in a bucket bitmap and therefore can
look up the next expiring timer very fast and O(1).
A further benefit of the concept is that the slack calculation which is done
on every timer start is no longer necessary because the granularity levels
provide natural batching already.
Our extensive testing with various loads did not show any performance
degradation vs. the current wheel implementation.
This patch does not address the 'fast lookup' issue as we wanted to make sure
that there is no regression introduced by the wheel redesign. The
optimizations are in follow up patches.
This patch contains fixes from Anna-Maria Gleixner and Richard Cochran.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094342.108621834@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We want to move the timer migration logic from a 'push' to a 'pull' model.
Under the current 'push' model pinned timers are handled via
a runtime API variant: mod_timer_pinned().
The 'pull' model requires us to store the pinned attribute of a timer
in the timer_list structure itself, as a new TIMER_PINNED bit in
timer->flags.
This flag must be set at initialization time and the timer APIs
recognize the flag.
This patch:
- Implements the new flag and associated new-style initialization
methods
- makes mod_timer() recognize new-style pinned timers,
- and adds some migration helper facility to allow
step by step conversion of old-style to new-style
pinned timers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094341.049338558@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull networking fixes from David Miller:
1) All users of AF_PACKET's fanout feature want a symmetric packet
header hash for load balancing purposes, so give it to them.
2) Fix vlan state synchronization in e1000e, from Jarod Wilson.
3) Use correct socket pointer in ip_skb_dst_mtu(), from Shmulik
Ladkani.
4) mlx5 bug fixes from Mohamad Haj Yahia, Daniel Jurgens, Matthew
Finlay, Rana Shahout, and Shaker Daibes. Mostly to do with
operation timeouts and PCI error handling.
5) Fix checksum handling in mirred packet action, from WANG Cong.
6) Set skb->dev correctly when transmitting in !protect_frames case of
macsec driver, from Daniel Borkmann.
7) Fix MTU calculation in geneve driver, from Haishuang Yan.
8) Missing netif_napi_del() in unregister path of qeth driver, from
Ursula Braun.
9) Handle malformed route netlink messages in decnet properly, from
Vergard Nossum.
10) Memory leak of percpu data in ipv6 routing code, from Martin KaFai
Lau.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (41 commits)
ipv6: Fix mem leak in rt6i_pcpu
net: fix decnet rtnexthop parsing
cxgb4: update latest firmware version supported
net/mlx5: Avoid setting unused var when modifying vport node GUID
bonding: fix enslavement slave link notifications
r8152: fix runtime function for RTL8152
qeth: delete napi struct when removing a qeth device
Revert "fsl/fman: fix error handling"
fsl/fman: fix error handling
cdc_ncm: workaround for EM7455 "silent" data interface
RDS: fix rds_tcp_init() error path
geneve: fix max_mtu setting
net: phy: dp83867: Fix initialization of PHYCR register
enc28j60: Fix race condition in enc28j60 driver
net: stmmac: Fix null-function call in ISR on stmmac1000
tipc: fix nl compat regression for link statistics
net: bcmsysport: Device stats are unsigned long
macsec: set actual real device for xmit when !protect_frames
net_sched: fix mirrored packets checksum
packet: Use symmetric hash for PACKET_FANOUT_HASH.
...
Pull fuse fix from Miklos Szeredi:
"This makes sure userspace filesystems are not broken by the parallel
lookups and readdir feature"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: serialize dirops by default
here's a batch of i915 fixes for 4.7.
* tag 'drm-intel-fixes-2016-06-30' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Fix missing unlock on error in i915_ppgtt_info()
drm/i915: Removing PCI IDs that are no longer listed as Kabylake.
drm/i915: Add more Kabylake PCI IDs.
drm/i915: Avoid early timeout during AUX transfers
drm/i915/hsw: Avoid early timeout during LCPLL disable/restore
drm/i915/lpt: Avoid early timeout during FDI PHY reset
drm/i915/bxt: Avoid early timeout during PLL enable
drm/i915: Refresh cached DP port register value on resume
Trying to make the ISA and PCI init functionality common turned out
to be a bad idea, because the ISA path depends on external
functionality.
Restore the previous behavior and limit the refactoring to PCI
interrupts only.
Fixes: 1fcb6a813c "ACPI,PCI,IRQ: remove redundant code in acpi_irq_penalty_init()"
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Tested-by: Wim Osterholt <wim@djo.tudelft.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Similar to commit 9b368814b3 ("net: fix bridge multicast packet checksum validation")
we need to fixup the checksum for CHECKSUM_COMPLETE when
pushing skb on RX path. Otherwise we get similar splats.
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
