Pull scheduler updates from Ingo Molnar:
- membarrier updates (Mathieu Desnoyers)
- SMP balancing optimizations (Mel Gorman)
- stats update optimizations (Peter Zijlstra)
- RT scheduler race fixes (Steven Rostedt)
- misc fixes and updates
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Use a recently used CPU as an idle candidate and the basis for SIS
sched/fair: Do not migrate if the prev_cpu is idle
sched/fair: Restructure wake_affine*() to return a CPU id
sched/fair: Remove unnecessary parameters from wake_affine_idle()
sched/rt: Make update_curr_rt() more accurate
sched/rt: Up the root domain ref count when passing it around via IPIs
sched/rt: Use container_of() to get root domain in rto_push_irq_work_func()
sched/core: Optimize update_stats_*()
sched/core: Optimize ttwu_stat()
membarrier/selftest: Test private expedited sync core command
membarrier/arm64: Provide core serializing command
membarrier/x86: Provide core serializing command
membarrier: Provide core serializing command, *_SYNC_CORE
lockin/x86: Implement sync_core_before_usermode()
locking: Introduce sync_core_before_usermode()
membarrier/selftest: Test global expedited command
membarrier: Provide GLOBAL_EXPEDITED command
membarrier: Document scheduler barrier requirements
powerpc, membarrier: Skip memory barrier in switch_mm()
membarrier/selftest: Test private expedited command
Pull networking fixes from David Miller:
1) Fix error path in netdevsim, from Jakub Kicinski.
2) Default values listed in tcp_wmem and tcp_rmem documentation were
inaccurate, from Tonghao Zhang.
3) Fix route leaks in SCTP, both for ipv4 and ipv6. From Alexey Kodanev
and Tommi Rantala.
4) Fix "MASK < Y" meant to be "MASK << Y" in xgbe driver, from Wolfram
Sang.
5) Use after free in u32_destroy_key(), from Paolo Abeni.
6) Fix two TX issues in be2net driver, from Suredh Reddy.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (25 commits)
be2net: Handle transmit completion errors in Lancer
be2net: Fix HW stall issue in Lancer
RDS: IB: Fix null pointer issue
nfp: fix kdoc warnings on nested structures
sample/bpf: fix erspan metadata
net: erspan: fix erspan config overwrite
net: erspan: fix metadata extraction
cls_u32: fix use after free in u32_destroy_key()
net: amd-xgbe: fix comparison to bitshift when dealing with a mask
net: phy: Handle not having GPIO enabled in the kernel
ibmvnic: fix empty firmware version and errors cleanup
sctp: fix dst refcnt leak in sctp_v4_get_dst
sctp: fix dst refcnt leak in sctp_v6_get_dst()
dwc-xlgmac: remove Jie Deng as co-maintainer
doc: Change the min default value of tcp_wmem/tcp_rmem.
samples/bpf: use bpf_set_link_xdp_fd
libbpf: add missing SPDX-License-Identifier
libbpf: add error reporting in XDP
libbpf: add function to setup XDP
tools: add netlink.h and if_link.h in tools uapi
...
Patch series "pipe: buffer limits fixes and cleanups", v2.
This series simplifies the sysctl handler for pipe-max-size and fixes
another set of bugs related to the pipe buffer limits:
- The root user wasn't allowed to exceed the limits when creating new
pipes.
- There was an off-by-one error when checking the limits, so a limit of
N was actually treated as N - 1.
- F_SETPIPE_SZ accepted values over UINT_MAX.
- Reading the pipe buffer limits could be racy.
This patch (of 7):
Before validating the given value against pipe_min_size,
do_proc_dopipe_max_size_conv() calls round_pipe_size(), which rounds the
value up to pipe_min_size. Therefore, the second check against
pipe_min_size is redundant. Remove it.
Link: http://lkml.kernel.org/r/20180111052902.14409-2-ebiggers3@gmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 92266d6ef6 ("async: simplify lowest_in_progress()")
which was simply wrong: In the case where domain is NULL, we now use the
wrong offsetof() in the list_first_entry macro, so we don't actually
fetch the ->cookie value, but rather the eight bytes located
sizeof(struct list_head) further into the struct async_entry.
On 64 bit, that's the data member, while on 32 bit, that's a u64 built
from func and data in some order.
I think the bug happens to be harmless in practice: It obviously only
affects callers which pass a NULL domain, and AFAICT the only such
caller is
async_synchronize_full() ->
async_synchronize_full_domain(NULL) ->
async_synchronize_cookie_domain(ASYNC_COOKIE_MAX, NULL)
and the ASYNC_COOKIE_MAX means that in practice we end up waiting for
the async_global_pending list to be empty - but it would break if
somebody happened to pass (void*)-1 as the data element to
async_schedule, and of course also if somebody ever does a
async_synchronize_cookie_domain(, NULL) with a "finite" cookie value.
Maybe the "harmless in practice" means this isn't -stable material. But
I'm not completely confident my quick git grep'ing is enough, and there
might be affected code in one of the earlier kernels that has since been
removed, so I'll leave the decision to the stable guys.
Link: http://lkml.kernel.org/r/20171128104938.3921-1-linux@rasmusvillemoes.dk
Fixes: 92266d6ef6 "async: simplify lowest_in_progress()"
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Adam Wallis <awallis@codeaurora.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nearly all modern compilers support a stack-protector option, and nearly
all modern distributions enable the kernel stack-protector, so enabling
this by default in kernel builds would make sense. However, Kconfig does
not have knowledge of available compiler features, so it isn't safe to
force on, as this would unconditionally break builds for the compilers or
architectures that don't have support. Instead, this introduces a new
option, CONFIG_CC_STACKPROTECTOR_AUTO, which attempts to discover the best
possible stack-protector available, and will allow builds to proceed even
if the compiler doesn't support any stack-protector.
This option is made the default so that kernels built with modern
compilers will be protected-by-default against stack buffer overflows,
avoiding things like the recent BlueBorne attack. Selection of a specific
stack-protector option remains available, including disabling it.
Additionally, tiny.config is adjusted to use CC_STACKPROTECTOR_NONE, since
that's the option with the least code size (and it used to be the default,
so we have to explicitly choose it there now).
Link: http://lkml.kernel.org/r/1510076320-69931-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull libnvdimm updates from Ross Zwisler:
- Require struct page by default for filesystem DAX to remove a number
of surprising failure cases. This includes failures with direct I/O,
gdb and fork(2).
- Add support for the new Platform Capabilities Structure added to the
NFIT in ACPI 6.2a. This new table tells us whether the platform
supports flushing of CPU and memory controller caches on unexpected
power loss events.
- Revamp vmem_altmap and dev_pagemap handling to clean up code and
better support future future PCI P2P uses.
- Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has
become out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL
spec, and instead rely on the generic ND_CMD_CALL approach used by
the two other IOCTL families, NVDIMM_FAMILY_{HPE,MSFT}.
- Enhance nfit_test so we can test some of the new things added in
version 1.6 of the DSM specification. This includes testing firmware
download and simulating the Last Shutdown State (LSS) status.
* tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (37 commits)
libnvdimm, namespace: remove redundant initialization of 'nd_mapping'
acpi, nfit: fix register dimm error handling
libnvdimm, namespace: make min namespace size 4K
tools/testing/nvdimm: force nfit_test to depend on instrumented modules
libnvdimm/nfit_test: adding support for unit testing enable LSS status
libnvdimm/nfit_test: add firmware download emulation
nfit-test: Add platform cap support from ACPI 6.2a to test
libnvdimm: expose platform persistence attribute for nd_region
acpi: nfit: add persistent memory control flag for nd_region
acpi: nfit: Add support for detect platform CPU cache flush on power loss
device-dax: Fix trailing semicolon
libnvdimm, btt: fix uninitialized err_lock
dax: require 'struct page' by default for filesystem dax
ext2: auto disable dax instead of failing mount
ext4: auto disable dax instead of failing mount
mm, dax: introduce pfn_t_special()
mm: Fix devm_memremap_pages() collision handling
mm: Fix memory size alignment in devm_memremap_pages_release()
memremap: merge find_dev_pagemap into get_dev_pagemap
memremap: change devm_memremap_pages interface to use struct dev_pagemap
...
Pull PCI updates from Bjorn Helgaas:
- skip AER driver error recovery callbacks for correctable errors
reported via ACPI APEI, as we already do for errors reported via the
native path (Tyler Baicar)
- fix DPC shared interrupt handling (Alex Williamson)
- print full DPC interrupt number (Keith Busch)
- enable DPC only if AER is available (Keith Busch)
- simplify DPC code (Bjorn Helgaas)
- calculate ASPM L1 substate parameter instead of hardcoding it (Bjorn
Helgaas)
- enable Latency Tolerance Reporting for ASPM L1 substates (Bjorn
Helgaas)
- move ASPM internal interfaces out of public header (Bjorn Helgaas)
- allow hot-removal of VGA devices (Mika Westerberg)
- speed up unplug and shutdown by assuming Thunderbolt controllers
don't support Command Completed events (Lukas Wunner)
- add AtomicOps support for GPU and Infiniband drivers (Felix Kuehling,
Jay Cornwall)
- expose "ari_enabled" in sysfs to help NIC naming (Stuart Hayes)
- clean up PCI DMA interface usage (Christoph Hellwig)
- remove PCI pool API (replaced with DMA pool) (Romain Perier)
- deprecate pci_get_bus_and_slot(), which assumed PCI domain 0 (Sinan
Kaya)
- move DT PCI code from drivers/of/ to drivers/pci/ (Rob Herring)
- add PCI-specific wrappers for dev_info(), etc (Frederick Lawler)
- remove warnings on sysfs mmap failure (Bjorn Helgaas)
- quiet ROM validation messages (Alex Deucher)
- remove redundant memory alloc failure messages (Markus Elfring)
- fill in types for compile-time VGA and other I/O port resources
(Bjorn Helgaas)
- make "pci=pcie_scan_all" work for Root Ports as well as Downstream
Ports to help AmigaOne X1000 (Bjorn Helgaas)
- add SPDX tags to all PCI files (Bjorn Helgaas)
- quirk Marvell 9128 DMA aliases (Alex Williamson)
- quirk broken INTx disable on Ceton InfiniTV4 (Bjorn Helgaas)
- fix CONFIG_PCI=n build by adding dummy pci_irqd_intx_xlate() (Niklas
Cassel)
- use DMA API to get MSI address for DesignWare IP (Niklas Cassel)
- fix endpoint-mode DMA mask configuration (Kishon Vijay Abraham I)
- fix ARTPEC-6 incorrect IS_ERR() usage (Wei Yongjun)
- add support for ARTPEC-7 SoC (Niklas Cassel)
- add endpoint-mode support for ARTPEC (Niklas Cassel)
- add Cadence PCIe host and endpoint controller driver (Cyrille
Pitchen)
- handle multiple INTx status bits being set in dra7xx (Vignesh R)
- translate dra7xx hwirq range to fix INTD handling (Vignesh R)
- remove deprecated Exynos PHY initialization code (Jaehoon Chung)
- fix MSI erratum workaround for HiSilicon Hip06/Hip07 (Dongdong Liu)
- fix NULL pointer dereference in iProc BCMA driver (Ray Jui)
- fix Keystone interrupt-controller-node lookup (Johan Hovold)
- constify qcom driver structures (Julia Lawall)
- rework Tegra config space mapping to increase space available for
endpoints (Vidya Sagar)
- simplify Tegra driver by using bus->sysdata (Manikanta Maddireddy)
- remove PCI_REASSIGN_ALL_BUS usage on Tegra (Manikanta Maddireddy)
- add support for Global Fabric Manager Server (GFMS) event to
Microsemi Switchtec switch driver (Logan Gunthorpe)
- add IDs for Switchtec PSX 24xG3 and PSX 48xG3 (Kelvin Cao)
* tag 'pci-v4.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (140 commits)
PCI: cadence: Add EndPoint Controller driver for Cadence PCIe controller
dt-bindings: PCI: cadence: Add DT bindings for Cadence PCIe endpoint controller
PCI: endpoint: Fix EPF device name to support multi-function devices
PCI: endpoint: Add the function number as argument to EPC ops
PCI: cadence: Add host driver for Cadence PCIe controller
dt-bindings: PCI: cadence: Add DT bindings for Cadence PCIe host controller
PCI: Add vendor ID for Cadence
PCI: Add generic function to probe PCI host controllers
PCI: generic: fix missing call of pci_free_resource_list()
PCI: OF: Add generic function to parse and allocate PCI resources
PCI: Regroup all PCI related entries into drivers/pci/Makefile
PCI/DPC: Reformat DPC register definitions
PCI/DPC: Add and use DPC Status register field definitions
PCI/DPC: Squash dpc_rp_pio_get_info() into dpc_process_rp_pio_error()
PCI/DPC: Remove unnecessary RP PIO register structs
PCI/DPC: Push dpc->rp_pio_status assignment into dpc_rp_pio_get_info()
PCI/DPC: Squash dpc_rp_pio_print_error() into dpc_rp_pio_get_info()
PCI/DPC: Make RP PIO log size check more generic
PCI/DPC: Rename local "status" to "dpc_status"
PCI/DPC: Squash dpc_rp_pio_print_tlp_header() into dpc_rp_pio_print_error()
...
The select_idle_sibling() (SIS) rewrite in commit:
10e2f1acd0 ("sched/core: Rewrite and improve select_idle_siblings()")
... replaced a domain iteration with a search that broadly speaking
does a wrapped walk of the scheduler domain sharing a last-level-cache.
While this had a number of improvements, one consequence is that two tasks
that share a waker/wakee relationship push each other around a socket. Even
though two tasks may be active, all cores are evenly used. This is great from
a search perspective and spreads a load across individual cores, but it has
adverse consequences for cpufreq. As each CPU has relatively low utilisation,
cpufreq may decide the utilisation is too low to used a higher P-state and
overall computation throughput suffers.
While individual cpufreq and cpuidle drivers may compensate by artifically
boosting P-state (at c0) or avoiding lower C-states (during idle), it does
not help if hardware-based cpufreq (e.g. HWP) is used.
This patch tracks a recently used CPU based on what CPU a task was running
on when it last was a waker a CPU it was recently using when a task is a
wakee. During SIS, the recently used CPU is used as a target if it's still
allowed by the task and is idle.
The benefit may be non-obvious so consider an example of two tasks
communicating back and forth. Task A may be an application doing IO where
task B is a kworker or kthread like journald. Task A may issue IO, wake
B and B wakes up A on completion. With the existing scheme this may look
like the following (potentially different IDs if SMT is in use but similar
principal applies).
A (cpu 0) wake B (wakes on cpu 1)
B (cpu 1) wake A (wakes on cpu 2)
A (cpu 2) wake B (wakes on cpu 3)
etc.
A careful reader may wonder why CPU 0 was not idle when B wakes A the
first time and it's simply due to the fact that A can be rescheduled to
another CPU and the pattern is that prev == target when B tries to wakeup A
and the information about CPU 0 has been lost.
With this patch, the pattern is more likely to be:
A (cpu 0) wake B (wakes on cpu 1)
B (cpu 1) wake A (wakes on cpu 0)
A (cpu 0) wake B (wakes on cpu 1)
etc
i.e. two communicating casts are more likely to use just two cores instead
of all available cores sharing a LLC.
The most dramatic speedup was noticed on dbench using the XFS filesystem on
UMA as clients interact heavily with workqueues in that configuration. Note
that a similar speedup is not observed on ext4 as the wakeup pattern
is different:
4.15.0-rc9 4.15.0-rc9
waprev-v1 biasancestor-v1
Hmean 1 287.54 ( 0.00%) 817.01 ( 184.14%)
Hmean 2 1268.12 ( 0.00%) 1781.24 ( 40.46%)
Hmean 4 1739.68 ( 0.00%) 1594.47 ( -8.35%)
Hmean 8 2464.12 ( 0.00%) 2479.56 ( 0.63%)
Hmean 64 1455.57 ( 0.00%) 1434.68 ( -1.44%)
The results can be less dramatic on NUMA where automatic balancing interferes
with the test. It's also known that network benchmarks running on localhost
also benefit quite a bit from this patch (roughly 10% on netperf RR for UDP
and TCP depending on the machine). Hackbench also seens small improvements
(6-11% depending on machine and thread count). The facebook schbench was also
tested but in most cases showed little or no different to wakeup latencies.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180130104555.4125-5-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
wake_affine_idle() prefers to move a task to the current CPU if the
wakeup is due to an interrupt. The expectation is that the interrupt
data is cache hot and relevant to the waking task as well as avoiding
a search. However, there is no way to determine if there was cache hot
data on the previous CPU that may exceed the interrupt data. Furthermore,
round-robin delivery of interrupts can migrate tasks around a socket where
each CPU is under-utilised. This can interact badly with cpufreq which
makes decisions based on per-cpu data. It has been observed on machines
with HWP that p-states are not boosted to their maximum levels even though
the workload is latency and throughput sensitive.
This patch uses the previous CPU for the task if it's idle and cache-affine
with the current CPU even if the current CPU is idle due to the wakup
being related to the interrupt. This reduces migrations at the cost of
the interrupt data not being cache hot when the task wakes.
A variety of workloads were tested on various machines and no adverse
impact was noticed that was outside noise. dbench on ext4 on UMA showed
roughly 10% reduction in the number of CPU migrations and it is a case
where interrupts are frequent for IO competions. In most cases, the
difference in performance is quite small but variability is often
reduced. For example, this is the result for pgbench running on a UMA
machine with different numbers of clients.
4.15.0-rc9 4.15.0-rc9
baseline waprev-v1
Hmean 1 22096.28 ( 0.00%) 22734.86 ( 2.89%)
Hmean 4 74633.42 ( 0.00%) 75496.77 ( 1.16%)
Hmean 7 115017.50 ( 0.00%) 113030.81 ( -1.73%)
Hmean 12 126209.63 ( 0.00%) 126613.40 ( 0.32%)
Hmean 16 131886.91 ( 0.00%) 130844.35 ( -0.79%)
Stddev 1 636.38 ( 0.00%) 417.11 ( 34.46%)
Stddev 4 614.64 ( 0.00%) 583.24 ( 5.11%)
Stddev 7 542.46 ( 0.00%) 435.45 ( 19.73%)
Stddev 12 173.93 ( 0.00%) 171.50 ( 1.40%)
Stddev 16 671.42 ( 0.00%) 680.30 ( -1.32%)
CoeffVar 1 2.88 ( 0.00%) 1.83 ( 36.26%)
Note that the different in performance is marginal but for low utilisation,
there is less variability.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180130104555.4125-4-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
