When taking a CPU down for suspend and resume, a tracepoint may be called
when the CPU has been designated offline. As tracepoints require RCU for
protection, they must not be called if the current CPU is offline.
Unfortunately, trace_tlb_flush() is called in this scenario as was noted
by LOCKDEP:
...
Disabling non-boot CPUs ...
intel_pstate CPU 1 exiting
===============================
smpboot: CPU 1 didn't die...
[ INFO: suspicious RCU usage. ]
3.19.0-rc7-next-20150204.1-iniza-small #1 Not tainted
-------------------------------
include/trace/events/tlb.h:35 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 0
no locks held by swapper/1/0.
stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.19.0-rc7-next-20150204.1-iniza-small #1
Hardware name: SAMSUNG ELECTRONICS CO., LTD. 530U3BI/530U4BI/530U4BH/530U3BI/530U4BI/530U4BH, BIOS 13XK 03/28/2013
0000000000000001 ffff88011a44fe18 ffffffff817e370d 0000000000000011
ffff88011a448290 ffff88011a44fe48 ffffffff810d6847 ffff8800c66b9600
0000000000000001 ffff88011a44c000 ffffffff81cb3900 ffff88011a44fe78
Call Trace:
[<ffffffff817e370d>] dump_stack+0x4c/0x65
[<ffffffff810d6847>] lockdep_rcu_suspicious+0xe7/0x120
[<ffffffff810b71a5>] idle_task_exit+0x205/0x2c0
[<ffffffff81054c4e>] play_dead_common+0xe/0x50
[<ffffffff81054ca5>] native_play_dead+0x15/0x140
[<ffffffff8102963f>] arch_cpu_idle_dead+0xf/0x20
[<ffffffff810cd89e>] cpu_startup_entry+0x37e/0x580
[<ffffffff81053e20>] start_secondary+0x140/0x150
intel_pstate CPU 2 exiting
...
By converting the tlb_flush tracepoint to a TRACE_EVENT_CONDITION where the
condition is cpu_online(smp_processor_id()), we can avoid calling RCU protected
code when the CPU is offline.
Link: http://lkml.kernel.org/r/CA+icZUUGiGDoL5NU8RuxKzFjoLjEKRtUWx=JB8B9a0EQv-eGzQ@mail.gmail.com
Cc: stable@vger.kernel.org # 3.17+
Fixes: d17d8f9ded "x86/mm: Add tracepoints for TLB flushes"
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The trace_tlb_flush() tracepoint can be called when a CPU is going offline.
When a CPU is offline, RCU is no longer watching that CPU and since the
tracepoint is protected by RCU, it must not be called. To prevent the
tlb_flush tracepoint from being called when the CPU is offline, it was
converted to a TRACE_EVENT_CONDITION where the condition checks if the
CPU is online before calling the tracepoint.
Unfortunately, this was not enough to stop lockdep from complaining about
it. Even though the RCU protected code of the tracepoint will never be
called, the condition is hidden within the tracepoint, and even though the
condition prevents RCU code from being called, the lockdep checks are
outside the tracepoint (this is to test tracepoints even when they are not
enabled).
Even though tracepoints should be checked to be RCU safe when they are not
enabled, the condition should still be considered when checking RCU.
Link: http://lkml.kernel.org/r/CA+icZUUGiGDoL5NU8RuxKzFjoLjEKRtUWx=JB8B9a0EQv-eGzQ@mail.gmail.com
Fixes: 3a630178fd "tracing: generate RCU warnings even when tracepoints are disabled"
Cc: stable@vger.kernel.org # 3.18+
Acked-by: Dave Hansen <dave@sr71.net>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
- Yann realized that the previous revert of new userspace ABI did not
go far enough, and we're still exposing a change that we don't want.
Revert even closer to 3.18 interface to make sure we get things right
in the long run.
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Merge tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband
Pull one more infiniband revert from Roland Dreier:
"One more last-second RDMA change for 3.19: Yann realized that the
previous revert of new userspace ABI did not go far enough, and we're
still exposing a change that we don't want. Revert even closer to
3.18 interface to make sure we get things right in the long run"
Yann Droneaud pipes up:
"I hope this could go in v3.19 as, at this stage, we don't want to
expose any bits of this ABI in a released kernel"
* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
Revert "IB/core: Add support for extended query device caps"
Pull btrfs fix from Chris Mason:
"Forrest Liu tracked down a missing blk_finish_plug in the btrfs
logging code. This isn't a new bug, and it's hard to hit. But, it's
safe enough for inclusion now, and in my for-linus branch"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: add missing blk_finish_plug in btrfs_sync_log()
Commit 28c8331d38 ("ARM: S5PV210: Remove support for board files")
removed the Kconfig symbols MACH_GONI and MACH_AQUILA. As a result the
dependencies of SND_SOC_GONI_AQUILA_WM8994 can never be met. So remove
the unbuildable "SoC I2S Audio support for AQUILA/GONI - WM8994".
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Mark Brown <broonie@kernel.org>
There's no %px extension. From the context I think the intention was to
dump the five bytes which were not as expected, and for that one should use
%ph.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
The remove logic properly searched the remaining chain for a matching
entry with an identical hash but it did this while searching from both
the old and new table. Instead in order to not leave stale references
behind we need to:
1. When growing and searching from the new table:
Search remaining chain for entry with same hash to avoid having
the new table directly point to a entry with a different hash.
2. When shrinking and searching from the old table:
Check if the element after the removed would create a cross
reference and avoid it if so.
These bugs were present from the beginning in nft_hash.
Also, both insert functions calculated the hash based on the mask of
the new table. This worked while growing. Wwhile shrinking, the mask
of the inew table is smaller than the mask of the old table. This lead
to a bit not being taken into account when selecting the bucket lock
and thus caused the wrong bucket to be locked eventually.
Fixes: 7e1e77636e ("lib: Resizable, Scalable, Concurrent Hash Table")
Fixes: 97defe1ecf ("rhashtable: Per bucket locks & deferred expansion/shrinking")
Reported-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Graf says:
====================
rhashtable fixes
This series fixes all remaining known issues with rhashtable that
have been reported. In particular the race condition reported by
Ying Xue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
During a resize, when two buckets in the larger table map to
a single bucket in the smaller table and the new table has already
been (partially) linked to the old table. Removal of an element
may result the bucket in the larger table to point to entries
which all hash to a different value than the bucket index. Thus
causing two buckets to point to the same sub chain after unzipping.
This is not illegal *during* the resize phase but after it has
completed.
Keep the old table around until all of the unzipping is done to
allow the removal code to only search for matching hashed entries
during this special period.
Reported-by: Ying Xue <ying.xue@windriver.com>
Fixes: 97defe1ecf ("rhashtable: Per bucket locks & deferred expansion/shrinking")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Catch hash miscalculations which result in hard to track down race
conditions.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This simplifies debugging of locking violations if compiled with
CONFIG_PROVE_LOCKING.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to wait for all RCU readers to complete after the last bit of
unzipping has been completed. Otherwise the old table is freed up
prematurely.
Fixes: 7e1e77636e ("lib: Resizable, Scalable, Concurrent Hash Table")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
rhashtable currently allows to use a bucket lock per bucket. This
requires multiple levels of complicated nested locking because when
resizing, a single bucket of the smaller table will map to two
buckets in the larger table. So far rhashtable has explicitly locked
both buckets in the larger table.
By excluding the highest bit of the hash from the bucket lock map and
thus only allowing locks to buckets in a ratio of 1:2, the locking
can be simplified a lot without losing the benefits of multiple locks.
Larger tables which benefit from multiple locks will not have a single
lock per bucket anyway.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The value computed by key_hashfn() is used by rhashtable_lookup_compare()
to traverse both tables during a resize. key_hashfn() must therefore
return the hash value without the buckets mask applied so it can be
masked to the size of each individual table.
Fixes: 97defe1ecf ("rhashtable: Per bucket locks & deferred expansion/shrinking")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add codec driver for the Maxim MAX98357A DAC.
Signed-off-by: Kenneth Westfield <kwestfie@codeaurora.org>
Acked-by: Banajit Goswami <bgoswami@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add documentation to the sound directory of the
device-tree bindings for the Maxim MAX98357A audio
DAC.
Signed-off-by: Kenneth Westfield <kwestfie@codeaurora.org>
Acked-by: Banajit Goswami <bgoswami@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Pull timer and x86 fix from Ingo Molnar:
"A CLOCK_TAI early expiry fix and an x86 microcode driver oops fix"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimer: Fix incorrect tai offset calculation for non high-res timer systems
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, microcode: Return error from driver init code when loader is disabled
Allow users the option to disable the driver for any hardware
which does not support HWP.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull scheduler fixes from Ingo Molnar:
"Misc fixes"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Fix deadline parameter modification handling
sched/wait: Remove might_sleep() from wait_event_cmd()
sched: Fix crash if cpuset_cpumask_can_shrink() is passed an empty cpumask
sched/fair: Avoid using uninitialized variable in preferred_group_nid()
We still need a validate_link_af() handler with an appropriate nla policy,
similarly as we have in IPv4 case, otherwise size validations are not being
done properly in that case.
Fixes: f53adae4ea ("net: ipv6: add tokenized interface identifier support")
Fixes: bc91b0f07a ("ipv6: addrconf: implement address generation modes")
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hopefully the final pull request for 3.19: this ended up with a
slightly higher volume than wished, but I put them all as they are
either stable or 3.19 regression fixes.
Most of commits are from ASoC, and have been stewed for a while in
linux-next. The only change in the common code is the regression
fixes for ASoC AC97 stuff wrt device registrations. The rest are
device-specific, mostly small fixes in various ASoC drivers and
ak411x on ice1724 boards.
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Merge tag 'sound-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Hopefully the final pull request for 3.19: this ended up with a
slightly higher volume than wished, but I put them all as they are
either stable or 3.19 regression fixes.
Most of commits are from ASoC, and have been stewed for a while in
linux-next. The only change in the common code is the regression
fixes for ASoC AC97 stuff wrt device registrations. The rest are
device-specific, mostly small fixes in various ASoC drivers and ak411x
on ice1724 boards"
* tag 'sound-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ASoC: Intel: fix sst firmware path for cht-bsw-rt5672
ARM: dts: Fix I2S1, I2S2 compatible for exynos4 SoCs
ASoC: sgtl5000: add delay before first I2C access
MAINTAINERS: ASoC: add maintainer for Intel BDW/HSW ASoC driver
ASoC: atmel_ssc_dai: fix the setting for DSP mode
ASoC: sgtl5000: Use shift mask when setting codec mode
ASoC: tlv320aic3x: Fix data delay configuration
ALSA: ak411x: Fix stall in work callback
ASoC: Intel: Used lock version to update shim registers
ASoC: wm8731: init mutex in i2c init path
ASoC: atmel_ssc_dai: fix start event for I2S mode
ASoC: rt5640: Add RT5642 ACPI ID for Intel Baytrail
ASoC: wm97xx: Reset AC'97 device before registering it
ASoC: Add support for allocating AC'97 device before registering it
There are a couple bugs with the error handling in this function.
1) If we can't allocate "rx_ring->rx_skbuff" then we should call
dma_free_coherent() but we don't.
2) free_rx_ring() frees "rx_ring->rx_skbuff_dma" and "rx_ring->rx_skbuff"
so calling it in a loop causes a double free.
Also it was a bit confusing how we sometimes freed things before doing
the goto. I've cleaned it up so it does error handling in normal kernel
style.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The aurora_inv_range(), aurora_clean_range() and aurora_flush_range()
functions are highly redundant, both in source and in object code, and
they are harder to understand than necessary.
By moving the range loop into the aurora_pa_range() function, they
become trivial wrappers, and the object code start looking like what
one would expect for an optimal implementation.
Further optimization may be possible by using the per-CPU "virtual"
registers to avoid the spinlocks in most cases.
(on Armada 370 RD and Armada XP GP, boot tested, plus a little bit of
DMA traffic by reading data from a SD card)
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The aurora cache controller is the only remaining user of a couple
of functions in this file and are completely unused when that is
disabled, leading to build warnings:
arch/arm/mm/cache-l2x0.c:167:13: warning: 'l2x0_cache_sync' defined but not used [-Wunused-function]
arch/arm/mm/cache-l2x0.c:184:13: warning: 'l2x0_flush_all' defined but not used [-Wunused-function]
arch/arm/mm/cache-l2x0.c:194:13: warning: 'l2x0_disable' defined but not used [-Wunused-function]
With the knowledge that the code is now aurora-specific, we can
simplify it noticeably:
- The pl310 errata workarounds are not needed on aurora and can be removed
- As confirmed by Thomas Petazzoni from the data sheet, the cache_wait()
macro is never needed.
- No need to hold the lock across atomic cache sync
- We can load the l2x0_base into a local variable across operations
There should be no functional change in this patch, but readability
and the generated object code improves, along with avoiding the
warnings.
(on Armada 370 RD and Armada XP GP, boot tested, plus a little bit of
DMA traffic by reading data from a SD card)
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge misc fixes from Andrew Morton:
"7 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/debug_pagealloc: fix build failure on ppc and some other archs
nilfs2: fix deadlock of segment constructor over I_SYNC flag
MAINTAINERS: remove SUPERH website
memcg, shmem: fix shmem migration to use lrucare
mm: export "high_memory" symbol on !MMU
.mailmap: update Konstantin Khlebnikov's email address
mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
Pull MIPS fixes from Ralf Baechle:
"The pending MIPS fixes for 3.19. All across the field and nothing
particularly severe or dramatic"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (23 commits)
IRQCHIP: mips-gic: Avoid rerouting timer IRQs for smp-cmp
MIPS: Fix syscall_get_nr for the syscall exit tracing.
MIPS: elf2ecoff: Ignore PT_MIPS_ABIFLAGS program headers.
MIPS: elf2ecoff: Rewrite main processing loop to switch.
MIPS: fork: Fix MSA/FPU/DSP context duplication race
MIPS: Fix C0_Pagegrain[IEC] support.
MIPS: traps: Fix inline asm ctc1 missing .set hardfloat
MIPS: mipsregs.h: Add write_32bit_cp1_register()
MIPS: Fix kernel lockup or crash after CPU offline/online
MIPS: OCTEON: fix kernel crash when offlining a CPU
MIPS: ARC: Fix build error.
MIPS: IRQ: Fix disable_irq on CPU IRQs
MIPS: smp-mt,smp-cmp: Enable all HW IRQs on secondary CPUs
MIPS: Fix restart of indirect syscalls
MIPS: ELF: fix loading o32 binaries on 64-bit kernels
MIPS: mips-cm: Fix sparse warnings
MIPS: Kconfig: Fix recursive dependency.
MIPS: Compat: Fix build error if CONFIG_MIPS32_COMPAT but no compat ABI.
MIPS: JZ4740: Fixup #include's (sparse)
MIPS: Wire up execveat(2).
...
This patch enhances debugging with the GPE reference count messages added.
No functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch implementes the QR_EC flushing support.
Grace periods are implemented from the detection of an SCI_EVT to the
submission/completion of the QR_EC transaction. During this period, all
EC command transactions are allowed to be submitted.
Note that query periods and event periods are intentionally distiguished to
allow further improvements.
1. Query period: from the detection of an SCI_EVT to the sumission of the
QR_EC command. This period is used for storming prevention, as currently
QR_EC is deferred to a work queue rather than directly issued from the
IRQ context even there is no other transactions pending, so malicous
SCI_EVT GPE can act like "level triggered" to trigger a GPE storm. We
need to be prepared for this. And in the future, we may change it to be
a part of the advance_transaction() where we will try QR_EC submission
in appropriate positions to avoid such GPE storming.
2. Event period: from the detection of an SCI_EVT to the completion of the
QR_EC command. We may extend it to the completion of _Qxx evaluation.
This is actually a grace period for event flushing, but we only flush
queries due to the reason stated in known issue 1. That's also why we
use EC_FLAGS_EVENT_xxx. During this period, QR_EC transactions need to
pass the flushable submission check.
In this patch, the following flags are implemented:
1. EC_FLAGS_EVENT_ENABLED: this is derived from the old
EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT handlings.
With this flag, the logics implemented by the original flag are
extended:
1. Old logic: unless both of the flags are set, the event poller will
not be scheduled, and
2. New logic: as soon as both of the flags are set, the evet poller will
be scheduled.
2. EC_FLAGS_EVENT_DETECTED: this is also derived from the old
EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT detection. It thus
can be used to indicate the storming prevention period for query
submission.
acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to
implement this period so that acpi_set_gpe() can be invoked under the
"reference count > 0" condition.
3. EC_FLAGS_EVENT_PENDING: this is newly added to indicate the grace period
for event flushing (query flushing for now).
acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to
implement this period so that the flushing process can wait until the
event handling (query transaction for now) to be completed.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch refines EC command storm prevention support.
Current command storming code is wrong, when the storming condition is
detected, it only flags the condition without doing anything for the
current command but performing storming prevention for the follow-up
commands. So:
1. The first command which suffers from the storming still suffers from
storming.
2. The follow-up commands which may not suffer from the storming are
unconditionally forced into the storming prevention mode.
Ideally, we should only enable storm prevention immediately after detection
for the current command so that the next command can try the
power/performance efficient interrupt mode again.
This patch improves the command storm prevention by disabling GPE right
after the detection and re-enabling it right before completing the command
transaction using the GPE storming prevention APIs. This thus deploys the
following GPE handling model:
1. acpi_enable_gpe()/acpi_disable_gpe() for reference count changes:
This set of APIs are used for EC usage reference counting.
2. acpi_set_gpe(ACPI_GPE_ENABLE)/acpi_set_gpe(ACPI_GPE_DISABLE):
This set of APIs are used for preventing GPE storm. They must be invoked
when the reference count > 0.
Note that as the storming prevention should always happen when there is
an outstanding request, or GPE enabling value will be messed up by the
races. This patch also adds BUG_ON() to enforces this rule to prevent
future bugs.
The msleep(1) used after completing a transaction is useless now as this
sounds like a guard time only useful for platforms that need the
EC_FLAGS_MSI quirks while we have fixed GPE race issues using the previous
raw handler mode enabling. It is kept to avoid regressions. A seperate
patch which deletes EC_FLAGS_MSI quirks should take care of deleting it.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch implements the EC command flushing support.
During the grace period indicated by EC_FLAGS_STARTED and EC_FLAGS_STOPPED,
all submitted EC command transactions can be completed and new submissions
are prevented before suspending so that the EC hardware can be ensured to
be in the idle state when the system is resumed.
There is a good indicator for flush support:
All acpi_ec_submit_request() is invoked after checking driver state with
acpi_ec_started() except the first one. This means all code paths can be
flushed as fast as possible by discarding the requests occurred after the
flush operation. The reference increased for such kind of code path is
wrapped by acpi_ec_submit_flushable_request().
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
By using the 2 flags, we can indicate an inter-mediate state where the
current transactions should be completed while the new transactions should
be dropped.
The comparison of the old flag and the new flags:
Old New
about to set BLOCKED STOPPED set / STARTED set
BLOCKED set STOPPED clear / STARTED clear
BLOCKED clear STOPPED clear / STARTED set
A new period can be indicated by the 2 flags. The new period is between the
point where we are about to set BLOCKED and the point when the BLOCKED is
set. The new flags facilitate us with acpi_ec_started() check to allow the
EC transaction to be submitted during the new period. This period thus can
be used as a grace period for the EC transaction flushing.
The only functional change after applying this patch is:
1. The GPE enabling/disabling is protected by the EC specific lock. We can
do this because of recent ACPICA GPE API enhancement. This is reasonable
as the GPE disabling/enabling state should only be determined by the EC
driver's state machine which is protected by the EC spinlock.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This new feature is to interpret AMD specific ACPI device to
platform device such as I2C, UART, GPIO found on AMD CZ and
later chipsets. It based on example intel LPSS. Now, it can
support AMD I2C, UART and GPIO.
Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch introduces a new module parameter for the KVM module; when it
is present, KVM attempts a bit of polling on every HLT before scheduling
itself out via kvm_vcpu_block.
This parameter helps a lot for latency-bound workloads---in particular
I tested it with O_DSYNC writes with a battery-backed disk in the host.
In this case, writes are fast (because the data doesn't have to go all
the way to the platters) but they cannot be merged by either the host or
the guest. KVM's performance here is usually around 30% of bare metal,
or 50% if you use cache=directsync or cache=writethrough (these
parameters avoid that the guest sends pointless flush requests, and
at the same time they are not slow because of the battery-backed cache).
The bad performance happens because on every halt the host CPU decides
to halt itself too. When the interrupt comes, the vCPU thread is then
migrated to a new physical CPU, and in general the latency is horrible
because the vCPU thread has to be scheduled back in.
With this patch performance reaches 60-65% of bare metal and, more
important, 99% of what you get if you use idle=poll in the guest. This
means that the tunable gets rid of this particular bottleneck, and more
work can be done to improve performance in the kernel or QEMU.
Of course there is some price to pay; every time an otherwise idle vCPUs
is interrupted by an interrupt, it will poll unnecessarily and thus
impose a little load on the host. The above results were obtained with
a mostly random value of the parameter (500000), and the load was around
1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU.
The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll,
that can be used to tune the parameter. It counts how many HLT
instructions received an interrupt during the polling period; each
successful poll avoids that Linux schedules the VCPU thread out and back
in, and may also avoid a likely trip to C1 and back for the physical CPU.
While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second.
Of these halts, almost all are failed polls. During the benchmark,
instead, basically all halts end within the polling period, except a more
or less constant stream of 50 per second coming from vCPUs that are not
running the benchmark. The wasted time is thus very low. Things may
be slightly different for Windows VMs, which have a ~10 ms timer tick.
The effect is also visible on Marcelo's recently-introduced latency
test for the TSC deadline timer. Though of course a non-RT kernel has
awful latency bounds, the latency of the timer is around 8000-10000 clock
cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC
deadline timer, thus, the effect is both a smaller average latency and
a smaller variance.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For assigning sysfs entries for a card device from the driver,
introduce a new helper function, snd_card_add_dev_attr(). In this
way, we can avoid the possible race between the device registration
and the sysfs addition / removal.
The driver can pass a new attribute group to add freely. This has to
be called before snd_card_register().
Currently, up to two extra groups can be added. More than that, it'll
return an error.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
While commit 7e36ef8205 ("IB/core: Temporarily disable
ex_query_device uverb") is correct as it makes the extended
QUERY_DEVICE uverb (which came as part of commit 5a77abf9a9
("IB/core: Add support for extended query device caps") and commit
860f10a799 ("IB/core: Add flags for on demand paging support")) not
available to userspace, it doesn't address the initial issue regarding
ib_copy_to_udata() [1][2].
Additionally, further discussions around this new uverb seems to
conclude it would require a different data structure than the one
currently described in <rdma/ib_user_verbs.h> [3].
Both of these issues require a revert of the changes, so this patch
partially reverts commit 8cdd312cfe ("IB/mlx5: Implement the ODP
capability query verb") and commit 860f10a799 ("IB/core: Add flags
for on demand paging support") and fully reverts commit 5a77abf9a9
("IB/core: Add support for extended query device caps").
[1] "Re: [PATCH v3 06/17] IB/core: Add support for extended query device caps"
http://mid.gmane.org/1418733236.2779.26.camel@opteya.com
[2] "Re: [PATCH] IB/core: Temporarily disable ex_query_device uverb"
http://mid.gmane.org/1423067503.3030.83.camel@opteya.com
[3] "RE: [PATCH v1 1/5] IB/uverbs: ex_query_device: answer must not depend on request's comp_mask"
http://mid.gmane.org/2807E5FD2F6FDA4886F6618EAC48510E0CC12C30@CRSMSX101.amr.corp.intel.com
Cc: Eli Cohen <eli@mellanox.com>
Cc: Haggai Eran <haggaie@mellanox.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
* Enable stuck queue detection for iwlmvm
* A few fixes for EBS scan
* Fixes for various failure paths
* Improvements for TDLS Offchannel
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Merge tag 'iwlwifi-next-for-kalle-2015-02-03' of https://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-next
* Add support for beamforming
* Enable stuck queue detection for iwlmvm
* A few fixes for EBS scan
* Fixes for various failure paths
* Improvements for TDLS Offchannel
The functions brcmu_pkt_buf_free_skb() and usb_free_urb() test whether
their argument is NULL and then return immediately. Thus the test around
the call is not needed.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
The relay_close() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
The functions kfree() and release_firmware() were called in a few cases
by the cw1200_load_firmware_cw1200() function during error handling even if
the passed variables contained still a null pointer.
Corresponding implementation details could be improved by adjustments for
jump targets.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
The release_firmware() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
