For each netns (except init_net), we initialize its null entry
in 3 places:
1) The template itself, as we use kmemdup()
2) Code around dst_init_metrics() in ip6_route_net_init()
3) ip6_route_dev_notify(), which is supposed to initialize it after
loopback registers
Unfortunately the last one still happens in a wrong order because
we expect to initialize net->ipv6.ip6_null_entry->rt6i_idev to
net->loopback_dev's idev, thus we have to do that after we add
idev to loopback. However, this notifier has priority == 0 same as
ipv6_dev_notf, and ipv6_dev_notf is registered after
ip6_route_dev_notifier so it is called actually after
ip6_route_dev_notifier. This is similar to commit 2f460933f5
("ipv6: initialize route null entry in addrconf_init()") which
fixes init_net.
Fix it by picking a smaller priority for ip6_route_dev_notifier.
Also, we have to release the refcnt accordingly when unregistering
loopback_dev because device exit functions are called before subsys
exit functions.
Acked-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Johannes Berg says:
====================
A couple more fixes:
* don't try to authenticate during reconfiguration, which causes
drivers to get confused
* fix a kernel-doc warning for a recently merged change
* fix MU-MIMO group configuration (relevant only for monitor mode)
* more rate flags fix: remove stray RX_ENC_FLAG_40MHZ
* fix IBSS probe response allocation size
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Congestion control modules that want full control over congestion
control behavior do not want the cwnd modifications controlled by
the sysctl_tcp_slow_start_after_idle code path.
So skip those code paths for CC modules that use the cong_control()
API.
As an example, those cwnd effects are not desired for the BBR congestion
control algorithm.
Fixes: c0402760f5 ("tcp: new CC hook to set sending rate with rate_sample in any CA state")
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv4 dst could use fi->fib_metrics to store metrics but fib_info
itself is refcnt'ed, so without taking a refcnt fi and
fi->fib_metrics could be freed while dst metrics still points to
it. This triggers use-after-free as reported by Andrey twice.
This patch reverts commit 2860583fe8 ("ipv4: Kill rt->fi") to
restore this reference counting. It is a quick fix for -net and
-stable, for -net-next, as Eric suggested, we can consider doing
reference counting for metrics itself instead of relying on fib_info.
IPv6 is very different, it copies or steals the metrics from mx6_config
in fib6_commit_metrics() so probably doesn't need a refcnt.
Decnet has already done the refcnt'ing, see dn_fib_semantic_match().
Fixes: 2860583fe8 ("ipv4: Kill rt->fi")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace @results_wk with @report_results, which was missed
in an earlier patch between revisions thereof.
Fixes: b34939b983 ("cfg80211: add request id to cfg80211_sched_scan_*() api")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Somehow I missed this in my RX rate cleanup series, causing some
drivers to not report correct bandwidth since this flag isn't
used by mac80211 anymore. Fix this, and make hwsim also report
higher bandwidths appropriately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Whole point of randomization was to hide server uptime, but an attacker
can simply start a syn flood and TCP generates 'old style' timestamps,
directly revealing server jiffies value.
Also, TSval sent by the server to a particular remote address vary
depending on syncookies being sent or not, potentially triggering PAWS
drops for innocent clients.
Lets implement proper randomization, including for SYNcookies.
Also we do not need to export sysctl_tcp_timestamps, since it is not
used from a module.
In v2, I added Florian feedback and contribution, adding tsoff to
tcp_get_cookie_sock().
v3 removed one unused variable in tcp_v4_connect() as Florian spotted.
Fixes: 95a22caee3 ("tcp: randomize tcp timestamp offsets for each connection")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Tested-by: Florian Westphal <fw@strlen.de>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull char/misc driver updates from Greg KH:
"Here is the big set of new char/misc driver drivers and features for
4.12-rc1.
There's lots of new drivers added this time around, new firmware
drivers from Google, more auxdisplay drivers, extcon drivers, fpga
drivers, and a bunch of other driver updates. Nothing major, except if
you happen to have the hardware for these drivers, and then you will
be happy :)
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits)
firmware: google memconsole: Fix return value check in platform_memconsole_init()
firmware: Google VPD: Fix return value check in vpd_platform_init()
goldfish_pipe: fix build warning about using too much stack.
goldfish_pipe: An implementation of more parallel pipe
fpga fr br: update supported version numbers
fpga: region: release FPGA region reference in error path
fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe()
mei: drop the TODO from samples
firmware: Google VPD sysfs driver
firmware: Google VPD: import lib_vpd source files
misc: lkdtm: Add volatile to intentional NULL pointer reference
eeprom: idt_89hpesx: Add OF device ID table
misc: ds1682: Add OF device ID table
misc: tsl2550: Add OF device ID table
w1: Remove unneeded use of assert() and remove w1_log.h
w1: Use kernel common min() implementation
uio_mf624: Align memory regions to page size and set correct offsets
uio_mf624: Refactor memory info initialization
uio: Allow handling of non page-aligned memory regions
hangcheck-timer: Fix typo in comment
...
Pull driver core updates from Greg KH:
"Very tiny pull request for 4.12-rc1 for the driver core this time
around.
There are some documentation fixes, an eventpoll.h fixup to make it
easier for the libc developers to take our header files directly, and
some very minor driver core fixes and changes.
All have been in linux-next for a very long time with no reported
issues"
* tag 'driver-core-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Revert "kref: double kref_put() in my_data_handler()"
driver core: don't initialize 'parent' in device_add()
drivers: base: dma-mapping: use nth_page helper
Documentation/ABI: add information about cpu_capacity
debugfs: set no_llseek in DEFINE_DEBUGFS_ATTRIBUTE
eventpoll.h: add missing epoll event masks
eventpoll.h: fix epoll event masks
Pull USB updates from Greg KH:
"Here is the big USB patchset for 4.12-rc1.
Lots of good stuff here, after many many many attempts, the kernel
finally has a working typeC interface, many thanks to Heikki and
Guenter and others who have taken the time to get this merged. It
wasn't an easy path for them at all.
There's also a staging driver that uses this new api, which is why
it's coming in through this tree.
Along with that, there's the usual huge number of changes for gadget
drivers, xhci, and other stuff. Johan also finally refactored pretty
much every driver that was looking at USB endpoints to do it in a
common way, which will help prevent any "badly-formed" devices from
causing problems in drivers. That too wasn't a simple task.
All of these have been in linux-next for a while with no reported
issues"
* tag 'usb-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (263 commits)
staging: typec: Fairchild FUSB302 Type-c chip driver
staging: typec: Type-C Port Controller Interface driver (tcpci)
staging: typec: USB Type-C Port Manager (tcpm)
usb: host: xhci: remove #ifdef around PM functions
usb: musb: don't mark of_dev_auxdata as initdata
usb: misc: legousbtower: Fix buffers on stack
USB: Revert "cdc-wdm: fix "out-of-sync" due to missing notifications"
usb: Make sure usb/phy/of gets built-in
USB: storage: e-mail update in drivers/usb/storage/unusual_devs.h
usb: host: xhci: print correct command ring address
usb: host: xhci: delete sp_dma_buffers for scratchpad
usb: host: xhci: using correct specification chapter reference for DCBAAP
xhci: switch to pci_alloc_irq_vectors
usb: host: xhci-plat: set resume_quirk() for R-Car controllers
usb: host: xhci-plat: add resume_quirk()
usb: host: xhci-plat: enable clk in resume timing
usb: host: plat: Enable xHCI plat runtime PM
USB: serial: ftdi_sio: add device ID for Microsemi/Arrow SF2PLUS Dev Kit
USB: serial: constify static arrays
usb: fix some references for /proc/bus/usb
...
Pull networking fixes from David Miller:
1) The wireless rate info fix from Johannes Berg.
2) When a RAW socket is in hdrincl mode, we need to make sure that the
user provided at least a minimally sized ipv4/ipv6 header. Fix from
Alexander Potapenko.
3) We must emit IFLA_PHYS_PORT_NAME netlink attributes using
nla_put_string() so that it is NULL terminated.
4) Fix a bug in TCP fastopen handling, wherein child sockets
erroneously inherit the fastopen_req from the parent, and later can
end up derefencing freed memory or doing a double free. From Eric
Dumazet.
5) Don't clear out netdev stats at close time in tg3 driver, from
YueHaibing.
6) Fix refcount leak in xt_CT, from Gao Feng.
7) In nft_set_bitmap() don't leak dummy elements, from Liping Zhang.
8) Fix deadlock due to taking the expectation lock twice, also from
Liping Zhang.
9) Make xt_socket work again with ipv6, from Peter Tirsek.
10) Don't allow IPV6 to be used with IPVS if ipv6.disable=1, from Paolo
Abeni.
11) Make the BPF loader more flexible wrt. changes to the bpf MAP entry
layout. From Jesper Dangaard Brouer.
12) Fix ethtool reported device name in aquantia driver, from Pavel
Belous.
13) Fix build failures due to the compile time size test not working in
netfilter conntrack. From Geert Uytterhoeven.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
cfg80211: make RATE_INFO_BW_20 the default
ipv6: initialize route null entry in addrconf_init()
qede: Fix possible misconfiguration of advertised autoneg value.
qed: Fix overriding of supported autoneg value.
qed*: Fix possible overflow for status block id field.
rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string
netvsc: make sure napi enabled before vmbus_open
aquantia: Fix driver name reported by ethtool
ipv4, ipv6: ensure raw socket message is big enough to hold an IP header
net/sched: remove redundant null check on head
tcp: do not inherit fastopen_req from parent
forcedeth: remove unnecessary carrier status check
ibmvnic: Move queue restarting in ibmvnic_tx_complete
ibmvnic: Record SKB RX queue during poll
ibmvnic: Continue skb processing after skb completion error
ibmvnic: Check for driver reset first in ibmvnic_xmit
ibmvnic: Wait for any pending scrqs entries at driver close
ibmvnic: Clean up tx pools when closing
ibmvnic: Whitespace correction in release_rx_pools
ibmvnic: Delete napi's when releasing driver resources
...
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.12 kernel cycle.
Core changes:
- Return NULL from gpiod_get_optional() when GPIOLIB is disabled.
This was a much discussed change. It affects use cases where people
write drivers that might or might not be using GPIO resources. I
have decided that this is the lesser evil right now.
- Make gpiod_count() behave consistently across different hardware
descriptions.
- Fix the syntax around open drain/open source to not infer active
high/low semantics.
New drivers:
- A new single-register fixed-direction framework driver for hardware
that have lines controlled by a single register that just work in
one direction (out or in), including IRQ support.
- Support the Fintek F71889A GPIO SuperIO controller.
- Support the National NI 169445 MMIO GPIO.
- Support for the X-Gene derivative of the DWC GPIO controller
- Support for the Rohm BD9571MWV-M PMIC GPIO controller.
- Refactor the Gemini GPIO driver to a generic Faraday FTGPIO driver
and replace both the Gemini and the Moxa ART custom drivers with
this driver.
Driver improvements:
- A whole slew of drivers have their spinlocks chaned to raw
spinlocks as they provide irqchips, and thus we are progressing on
realtime compliance.
- Use devm_irq_alloc_descs() in a slew of drivers, getting managed
resources.
- Support for the embedded PWM controller inside the MVEBU driver.
- Debounce, open source and open drain support for the Aspeed driver.
- Misc smaller fixes like spelling and syntax and whatnot"
* tag 'gpio-v4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (77 commits)
gpio: f7188x: Add a missing break
gpio: omap: return error if requested debounce time is not possible
gpio: Add ROHM BD9571MWV-M PMIC GPIO driver
gpio: gpio-wcove: fix GPIO IRQ status mask
gpio: DT bindings, move tca9554 from pcf857x to pca953x
gpio: move tca9554 from pcf857x to pca953x
gpio: arizona: Correct check whether the pin is an input
gpio: Add XRA1403 DTS binding documentation
dt-bindings: add exar to vendor prefixes list
gpio: gpio-wcove: fix irq pending status bit width
gpio: dwapb: use dwapb_read instead of readl_relaxed
gpio: aspeed: Add open-source and open-drain support
gpio: aspeed: Add debounce support
gpio: aspeed: dt: Add optional clocks property
gpio: aspeed: dt: Fix description alignment in bindings document
gpio: mvebu: Add limited PWM support
gpio: Use unsigned int for interrupt numbers
gpio: f7188x: Add F71889A GPIO support.
gpio: core: Decouple open drain/source flag with active low/high
gpio: arizona: Correct handling for reading input GPIOs
...
Pull x86 platform-drivers update from Darren Hart:
"This represents a significantly larger and more complex set of changes
than those of prior merge windows.
In particular, we had several changes with dependencies on other
subsystems which we felt were best managed through merges of immutable
branches, including one each from input, i2c, and leds. Two patches
for the watchdog subsystem are included after discussion with Wim and
Guenter following a collision in linux-next (this should be resolved
and you should only see these two appear in this pull request). These
are called out in the "External" section below.
Summary of changes:
- significant further cleanup of fujitsu-laptop and hp-wmi
- new model support for ideapad, asus, silead, and xiaomi
- new hotkeys for thinkpad and models using intel-vbtn
- dell keyboard backlight improvements
- build and dependency improvements
- intel * ipc fixes, cleanups, and api updates
- single isolated fixes noted below
External:
- watchdog: iTCO_wdt: Add PMC specific noreboot update api
- watchdog: iTCO_wdt: cleanup set/unset no_reboot_bit functions
- Merge branch 'ib/4.10-sparse-keymap-managed'
- Merge branch 'i2c/for-INT33FE'
- Merge branch 'linux-leds/dell-laptop-changes-for-4.12'
platform/x86:
- Add Intel Cherry Trail ACPI INT33FE device driver
- remove sparse_keymap_free() calls
- Make SILEAD_DMI depend on TOUCHSCREEN_SILEAD
asus-wmi:
- try to set als by default
- fix cpufv sysfs file permission
acer-wmi:
- setup accelerometer when ACPI device was found
ideapad-laptop:
- Add IdeaPad V310-15ISK to no_hw_rfkill
- Add IdeaPad 310-15IKB to no_hw_rfkill
intel_pmc_ipc:
- use gcr mem base for S0ix counter read
- Fix iTCO_wdt GCS memory mapping failure
- Add pmc gcr read/write/update api's
- fix gcr offset
dell-laptop:
- Add keyboard backlight timeout AC settings
- Handle return error form dell_get_intensity.
- Protect kbd_state against races
- Refactor kbd_led_triggers_store()
hp-wireless:
- reuse module_acpi_driver
- add Xiaomi's hardware id to the supported list
intel-vbtn:
- add volume up and down
INT33FE:
- add i2c dependency
hp-wmi:
- Cleanup exit paths
- Do not shadow errors in sysfs show functions
- Use DEVICE_ATTR_(RO|RW) helper macros
- Refactor dock and tablet state fetchers
- Cleanup wireless get_(hw|sw)state functions
- Refactor redundant HPWMI_READ functions
- Standardize enum usage for constants
- Cleanup local variable declarations
- Do not shadow error values
- Fix detection for dock and tablet mode
- Fix error value for hp_wmi_tablet_state
fujitsu-laptop:
- simplify error handling in acpi_fujitsu_laptop_add()
- do not log LED registration failures
- switch to managed LED class devices
- reorganize LED-related code
- refactor LED registration
- select LEDS_CLASS
- remove redundant fields from struct fujitsu_bl
- account for backlight power when determining brightness
- do not log set_lcd_level() failures in bl_update_status()
- ignore errors when setting backlight power
- make disable_brightness_adjust a boolean
- clean up use_alt_lcd_levels handling
- sync brightness in set_lcd_level()
- simplify set_lcd_level()
- merge set_lcd_level_alt() into set_lcd_level()
- switch to a managed backlight device
- only handle backlight when appropriate
- update debug message logged by call_fext_func()
- rename call_fext_func() arguments
- simplify call_fext_func()
- clean up local variables in call_fext_func()
- remove keycode fields from struct fujitsu_bl
- model-dependent sparse keymap overrides
- use a sparse keymap for hotkey event generation
- switch to a managed hotkey input device
- refactor hotkey input device setup
- use a sparse keymap for brightness key events
- switch to a managed backlight input device
- refactor backlight input device setup
- remove pf_device field from struct fujitsu_bl
- only register platform device if FUJ02E3 is present
- add and remove platform device in separate functions
- simplify platform device attribute definitions
- remove backlight-related attributes from the platform device
- cleanup error labels in fujitsu_init()
- only register backlight device if FUJ02B1 is present
- sync backlight power status in acpi_fujitsu_laptop_add()
- register backlight device in a separate function
- simplify brightness key event generation logic
- decrease indentation in acpi_fujitsu_bl_notify()
intel-hid:
- Add missing ->thaw callback
- do not set parents of input devices explicitly
- remove redundant set_bit() call
- use devm_input_allocate_device() for HID events input device
- make intel_hid_set_enable() take a boolean argument
- simplify enabling/disabling HID events
silead_dmi:
- Add touchscreen info for Surftab Wintron 7.0
- Abort early if DMI does not match
- Do not treat all devices as i2c_clients
- Add entry for Insyde 7W tablets
- Constify properties arrays
intel_scu_ipc:
- Introduce intel_scu_ipc_raw_command()
- Introduce SCU_DEVICE() macro
- Remove redundant subarch check
- Rearrange init sequence
- Platform data is mandatory
asus-nb-wmi:
- Add wapf4 quirk for the X302UA
dell-*:
- Call new led hw_changed API on kbd brightness change
- Add a generic dell-laptop notifier chain
eeepc-laptop:
- Skip unknown key messages 0x50 0x51
thinkpad_acpi:
- add mapping for new hotkeys
- guard generic hotkey case"
* tag 'platform-drivers-x86-v4.12-1' of git://git.infradead.org/linux-platform-drivers-x86: (108 commits)
platform/x86: Make SILEAD_DMI depend on TOUCHSCREEN_SILEAD
platform/x86: asus-wmi: try to set als by default
platform/x86: asus-wmi: fix cpufv sysfs file permission
platform/x86: acer-wmi: setup accelerometer when ACPI device was found
platform/x86: ideapad-laptop: Add IdeaPad V310-15ISK to no_hw_rfkill
platform/x86: intel_pmc_ipc: use gcr mem base for S0ix counter read
platform/x86: intel_pmc_ipc: Fix iTCO_wdt GCS memory mapping failure
watchdog: iTCO_wdt: Add PMC specific noreboot update api
watchdog: iTCO_wdt: cleanup set/unset no_reboot_bit functions
platform/x86: intel_pmc_ipc: Add pmc gcr read/write/update api's
platform/x86: intel_pmc_ipc: fix gcr offset
platform/x86: dell-laptop: Add keyboard backlight timeout AC settings
platform/x86: dell-laptop: Handle return error form dell_get_intensity.
platform/x86: hp-wireless: reuse module_acpi_driver
platform/x86: intel-vbtn: add volume up and down
platform/x86: INT33FE: add i2c dependency
platform/x86: hp-wmi: Cleanup exit paths
platform/x86: hp-wmi: Do not shadow errors in sysfs show functions
platform/x86: hp-wmi: Use DEVICE_ATTR_(RO|RW) helper macros
platform/x86: hp-wmi: Refactor dock and tablet state fetchers
...
Pull xen updates from Juergen Gross:
"Xen fixes and featrues for 4.12. The main changes are:
- enable building the kernel with Xen support but without enabling
paravirtualized mode (Vitaly Kuznetsov)
- add a new 9pfs xen frontend driver (Stefano Stabellini)
- simplify Xen's cpuid handling by making use of cpu capabilities
(Juergen Gross)
- add/modify some headers for new Xen paravirtualized devices
(Oleksandr Andrushchenko)
- EFI reset_system support under Xen (Julien Grall)
- and the usual cleanups and corrections"
* tag 'for-linus-4.12b-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (57 commits)
xen: Move xen_have_vector_callback definition to enlighten.c
xen: Implement EFI reset_system callback
arm/xen: Consolidate calls to shutdown hypercall in a single helper
xen: Export xen_reboot
xen/x86: Call xen_smp_intr_init_pv() on BSP
xen: Revert commits da72ff5bfc and 72a9b18629
xen/pvh: Do not fill kernel's e820 map in init_pvh_bootparams()
xen/scsifront: use offset_in_page() macro
xen/arm,arm64: rename __generic_dma_ops to xen_get_dma_ops
xen/arm,arm64: fix xen_dma_ops after 815dd18 "Consolidate get_dma_ops..."
xen/9pfs: select CONFIG_XEN_XENBUS_FRONTEND
x86/cpu: remove hypervisor specific set_cpu_features
vmware: set cpu capabilities during platform initialization
x86/xen: use capabilities instead of fake cpuid values for xsave
x86/xen: use capabilities instead of fake cpuid values for x2apic
x86/xen: use capabilities instead of fake cpuid values for mwait
x86/xen: use capabilities instead of fake cpuid values for acpi
x86/xen: use capabilities instead of fake cpuid values for acc
x86/xen: use capabilities instead of fake cpuid values for mtrr
x86/xen: use capabilities instead of fake cpuid values for aperf
...
Due to the way I did the RX bitrate conversions in mac80211 with
spatch, going setting flags to setting the value, many drivers now
don't set the bandwidth value for 20 MHz, since with the flags it
wasn't necessary to (there was no 20 MHz flag, only the others.)
Rather than go through and try to fix up all the drivers, instead
renumber the enum so that 20 MHz, which is the typical bandwidth,
actually has the value 0, making those drivers all work again.
If VHT was hit used with a driver not reporting it, e.g. iwlmvm,
this manifested in hitting the bandwidth warning in
cfg80211_calculate_bitrate_vht().
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Andrey reported a crash on init_net.ipv6.ip6_null_entry->rt6i_idev
since it is always NULL.
This is clearly wrong, we have code to initialize it to loopback_dev,
unfortunately the order is still not correct.
loopback_dev is registered very early during boot, we lose a chance
to re-initialize it in notifier. addrconf_init() is called after
ip6_route_init(), which means we have no chance to correct it.
Fix it by moving this initialization explicitly after
ipv6_add_dev(init_net.loopback_dev) in addrconf_init().
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Value for status block id could be more than 256 in 100G mode, need to
update its data type from u8 to u16.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull modules updates from Jessica Yu:
- Minor code cleanups
- Fix section alignment for .init_array
* tag 'modules-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
kallsyms: Use bounded strnchr() when parsing string
module: Unify the return value type of try_module_get
module: set .init_array alignment to 8
Pull tracing updates from Steven Rostedt:
"New features for this release:
- Pretty much a full rewrite of the processing of function plugins.
i.e. echo do_IRQ:stacktrace > set_ftrace_filter
- The rewrite was needed to add plugins to be unique to tracing
instances. i.e. mkdir instance/foo; cd instances/foo; echo
do_IRQ:stacktrace > set_ftrace_filter The old way was written very
hacky. This removes a lot of those hacks.
- New "function-fork" tracing option. When set, pids in the
set_ftrace_pid will have their children added when the processes
with their pids listed in the set_ftrace_pid file forks.
- Exposure of "maxactive" for kretprobe in kprobe_events
- Allow for builtin init functions to be traced by the function
tracer (via the kernel command line). Module init function tracing
will come in the next release.
- Added more selftests, and have selftests also test in an instance"
* tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits)
ring-buffer: Return reader page back into existing ring buffer
selftests: ftrace: Allow some event trigger tests to run in an instance
selftests: ftrace: Have some basic tests run in a tracing instance too
selftests: ftrace: Have event tests also run in an tracing instance
selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances
selftests: ftrace: Allow some tests to be run in a tracing instance
tracing/ftrace: Allow for instances to trigger their own stacktrace probes
tracing/ftrace: Allow for the traceonoff probe be unique to instances
tracing/ftrace: Enable snapshot function trigger to work with instances
tracing/ftrace: Allow instances to have their own function probes
tracing/ftrace: Add a better way to pass data via the probe functions
ftrace: Dynamically create the probe ftrace_ops for the trace_array
tracing: Pass the trace_array into ftrace_probe_ops functions
tracing: Have the trace_array hold the list of registered func probes
ftrace: If the hash for a probe fails to update then free what was initialized
ftrace: Have the function probes call their own function
ftrace: Have each function probe use its own ftrace_ops
ftrace: Have unregister_ftrace_function_probe_func() return a value
ftrace: Add helper function ftrace_hash_move_and_update_ops()
ftrace: Remove data field from ftrace_func_probe structure
...
Merge misc updates from Andrew Morton:
- a few misc things
- most of MM
- KASAN updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits)
kasan: separate report parts by empty lines
kasan: improve double-free report format
kasan: print page description after stacks
kasan: improve slab object description
kasan: change report header
kasan: simplify address description logic
kasan: change allocation and freeing stack traces headers
kasan: unify report headers
kasan: introduce helper functions for determining bug type
mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page
mm: hwpoison: call shake_page() unconditionally
mm/swapfile.c: fix swap space leak in error path of swap_free_entries()
mm/gup.c: fix access_ok() argument type
mm/truncate: avoid pointless cleancache_invalidate_inode() calls.
mm/truncate: bail out early from invalidate_inode_pages2_range() if mapping is empty
fs/block_dev: always invalidate cleancache in invalidate_bdev()
fs: fix data invalidation in the cleancache during direct IO
zram: reduce load operation in page_same_filled
zram: use zram_free_page instead of open-coded
zram: introduce zram data accessor
...
The memory controllers stat function names are awkwardly long and
arbitrarily different from the zone and node stat functions.
The current interface is named:
mem_cgroup_read_stat()
mem_cgroup_update_stat()
mem_cgroup_inc_stat()
mem_cgroup_dec_stat()
mem_cgroup_update_page_stat()
mem_cgroup_inc_page_stat()
mem_cgroup_dec_page_stat()
This patch renames it to match the corresponding node stat functions:
memcg_page_state() [node_page_state()]
mod_memcg_state() [mod_node_state()]
inc_memcg_state() [inc_node_state()]
dec_memcg_state() [dec_node_state()]
mod_memcg_page_state() [mod_node_page_state()]
inc_memcg_page_state() [inc_node_page_state()]
dec_memcg_page_state() [dec_node_page_state()]
Link: http://lkml.kernel.org/r/20170404220148.28338-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 59dc76b0d4 ("mm: vmscan: reduce size of inactive file
list") we noticed bigger IO spikes during changes in cache access
patterns.
The patch in question shrunk the inactive list size to leave more room
for the current workingset in the presence of streaming IO. However,
workingset transitions that previously happened on the inactive list are
now pushed out of memory and incur more refaults to complete.
This patch disables active list protection when refaults are being
observed. This accelerates workingset transitions, and allows more of
the new set to establish itself from memory, without eating into the
ability to protect the established workingset during stable periods.
The workloads that were measurably affected for us were hit pretty bad
by it, with refault/majfault rates doubling and tripling during cache
transitions, and the machines sustaining half-hour periods of 100% IO
utilization, where they'd previously have sub-minute peaks at 60-90%.
Stateful services that handle user data tend to be more conservative
with kernel upgrades. As a result we hit most page cache issues with
some delay, as was the case here.
The severity seemed to warrant a stable tag.
Fixes: 59dc76b0d4 ("mm: vmscan: reduce size of inactive file list")
Link: http://lkml.kernel.org/r/20170404220052.27593-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
GFP_NOFS context is used for the following 5 reasons currently:
- to prevent from deadlocks when the lock held by the allocation
context would be needed during the memory reclaim
- to prevent from stack overflows during the reclaim because the
allocation is performed from a deep context already
- to prevent lockups when the allocation context depends on other
reclaimers to make a forward progress indirectly
- just in case because this would be safe from the fs POV
- silence lockdep false positives
Unfortunately overuse of this allocation context brings some problems to
the MM. Memory reclaim is much weaker (especially during heavy FS
metadata workloads), OOM killer cannot be invoked because the MM layer
doesn't have enough information about how much memory is freeable by the
FS layer.
In many cases it is far from clear why the weaker context is even used
and so it might be used unnecessarily. We would like to get rid of
those as much as possible. One way to do that is to use the flag in
scopes rather than isolated cases. Such a scope is declared when really
necessary, tracked per task and all the allocation requests from within
the context will simply inherit the GFP_NOFS semantic.
Not only this is easier to understand and maintain because there are
much less problematic contexts than specific allocation requests, this
also helps code paths where FS layer interacts with other layers (e.g.
crypto, security modules, MM etc...) and there is no easy way to convey
the allocation context between the layers.
Introduce memalloc_nofs_{save,restore} API to control the scope of
GFP_NOFS allocation context. This is basically copying
memalloc_noio_{save,restore} API we have for other restricted allocation
context GFP_NOIO. The PF_MEMALLOC_NOFS flag already exists and it is
just an alias for PF_FSTRANS which has been xfs specific until recently.
There are no more PF_FSTRANS users anymore so let's just drop it.
PF_MEMALLOC_NOFS is now checked in the MM layer and drops __GFP_FS
implicitly same as PF_MEMALLOC_NOIO drops __GFP_IO. memalloc_noio_flags
is renamed to current_gfp_context because it now cares about both
PF_MEMALLOC_NOFS and PF_MEMALLOC_NOIO contexts. Xfs code paths preserve
their semantic. kmem_flags_convert() doesn't need to evaluate the flag
anymore.
This patch shouldn't introduce any functional changes.
Let's hope that filesystems will drop direct GFP_NOFS (resp. ~__GFP_FS)
usage as much as possible and only use a properly documented
memalloc_nofs_{save,restore} checkpoints where they are appropriate.
[akpm@linux-foundation.org: fix comment typo, reflow comment]
Link: http://lkml.kernel.org/r/20170306131408.9828-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current implementation of the reclaim lockup detection can lead to
false positives and those even happen and usually lead to tweak the code
to silence the lockdep by using GFP_NOFS even though the context can use
__GFP_FS just fine.
See
http://lkml.kernel.org/r/20160512080321.GA18496@dastard
as an example.
=================================
[ INFO: inconsistent lock state ]
4.5.0-rc2+ #4 Tainted: G O
---------------------------------
inconsistent {RECLAIM_FS-ON-R} -> {IN-RECLAIM_FS-W} usage.
kswapd0/543 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&xfs_nondir_ilock_class){++++-+}, at: xfs_ilock+0x177/0x200 [xfs]
{RECLAIM_FS-ON-R} state was registered at:
mark_held_locks+0x79/0xa0
lockdep_trace_alloc+0xb3/0x100
kmem_cache_alloc+0x33/0x230
kmem_zone_alloc+0x81/0x120 [xfs]
xfs_refcountbt_init_cursor+0x3e/0xa0 [xfs]
__xfs_refcount_find_shared+0x75/0x580 [xfs]
xfs_refcount_find_shared+0x84/0xb0 [xfs]
xfs_getbmap+0x608/0x8c0 [xfs]
xfs_vn_fiemap+0xab/0xc0 [xfs]
do_vfs_ioctl+0x498/0x670
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x12/0x6f
CPU0
----
lock(&xfs_nondir_ilock_class);
<Interrupt>
lock(&xfs_nondir_ilock_class);
*** DEADLOCK ***
3 locks held by kswapd0/543:
stack backtrace:
CPU: 0 PID: 543 Comm: kswapd0 Tainted: G O 4.5.0-rc2+ #4
Call Trace:
lock_acquire+0xd8/0x1e0
down_write_nested+0x5e/0xc0
xfs_ilock+0x177/0x200 [xfs]
xfs_reflink_cancel_cow_range+0x150/0x300 [xfs]
xfs_fs_evict_inode+0xdc/0x1e0 [xfs]
evict+0xc5/0x190
dispose_list+0x39/0x60
prune_icache_sb+0x4b/0x60
super_cache_scan+0x14f/0x1a0
shrink_slab.part.63.constprop.79+0x1e9/0x4e0
shrink_zone+0x15e/0x170
kswapd+0x4f1/0xa80
kthread+0xf2/0x110
ret_from_fork+0x3f/0x70
To quote Dave:
"Ignoring whether reflink should be doing anything or not, that's a
"xfs_refcountbt_init_cursor() gets called both outside and inside
transactions" lockdep false positive case. The problem here is lockdep
has seen this allocation from within a transaction, hence a GFP_NOFS
allocation, and now it's seeing it in a GFP_KERNEL context. Also note
that we have an active reference to this inode.
So, because the reclaim annotations overload the interrupt level
detections and it's seen the inode ilock been taken in reclaim
("interrupt") context, this triggers a reclaim context warning where
it thinks it is unsafe to do this allocation in GFP_KERNEL context
holding the inode ilock..."
This sounds like a fundamental problem of the reclaim lock detection.
It is really impossible to annotate such a special usecase IMHO unless
the reclaim lockup detection is reworked completely. Until then it is
much better to provide a way to add "I know what I am doing flag" and
mark problematic places. This would prevent from abusing GFP_NOFS flag
which has a runtime effect even on configurations which have lockdep
disabled.
Introduce __GFP_NOLOCKDEP flag which tells the lockdep gfp tracking to
skip the current allocation request.
While we are at it also make sure that the radix tree doesn't
accidentaly override tags stored in the upper part of the gfp_mask.
Link: http://lkml.kernel.org/r/20170306131408.9828-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
madv()'s MADV_FREE indicate pages are 'lazyfree'. They are still
anonymous pages, but they can be freed without pageout. To distinguish
these from normal anonymous pages, we clear their SwapBacked flag.
MADV_FREE pages could be freed without pageout, so they pretty much like
used once file pages. For such pages, we'd like to reclaim them once
there is memory pressure. Also it might be unfair reclaiming MADV_FREE
pages always before used once file pages and we definitively want to
reclaim the pages before other anonymous and file pages.
To speed up MADV_FREE pages reclaim, we put the pages into
LRU_INACTIVE_FILE list. The rationale is LRU_INACTIVE_FILE list is tiny
nowadays and should be full of used once file pages. Reclaiming
MADV_FREE pages will not have much interfere of anonymous and active
file pages. And the inactive file pages and MADV_FREE pages will be
reclaimed according to their age, so we don't reclaim too many MADV_FREE
pages too. Putting the MADV_FREE pages into LRU_INACTIVE_FILE_LIST also
means we can reclaim the pages without swap support. This idea is
suggested by Johannes.
This patch doesn't move MADV_FREE pages to LRU_INACTIVE_FILE list yet to
avoid bisect failure, next patch will do it.
The patch is based on Minchan's original patch.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/2f87063c1e9354677b7618c647abde77b07561e5.1487965799.git.shli@fb.com
Signed-off-by: Shaohua Li <shli@fb.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: fix some MADV_FREE issues", v5.
We are trying to use MADV_FREE in jemalloc. Several issues are found.
Without solving the issues, jemalloc can't use the MADV_FREE feature.
- Doesn't support system without swap enabled. Because if swap is off,
we can't or can't efficiently age anonymous pages. And since
MADV_FREE pages are mixed with other anonymous pages, we can't
reclaim MADV_FREE pages. In current implementation, MADV_FREE will
fallback to MADV_DONTNEED without swap enabled. But in our
environment, a lot of machines don't enable swap. This will prevent
our setup using MADV_FREE.
- Increases memory pressure. page reclaim bias file pages reclaim
against anonymous pages. This doesn't make sense for MADV_FREE pages,
because those pages could be freed easily and refilled with very
slight penality. Even page reclaim doesn't bias file pages, there is
still an issue, because MADV_FREE pages and other anonymous pages are
mixed together. To reclaim a MADV_FREE page, we probably must scan a
lot of other anonymous pages, which is inefficient. In our test, we
usually see oom with MADV_FREE enabled and nothing without it.
- Accounting. There are two accounting problems. We don't have a global
accounting. If the system is abnormal, we don't know if it's a
problem from MADV_FREE side. The other problem is RSS accounting.
MADV_FREE pages are accounted as normal anon pages and reclaimed
lazily, so application's RSS becomes bigger. This confuses our
workloads. We have monitoring daemon running and if it finds
applications' RSS becomes abnormal, the daemon will kill the
applications even kernel can reclaim the memory easily.
To address the first the two issues, we can either put MADV_FREE pages
into a separate LRU list (Minchan's previous patches and V1 patches), or
put them into LRU_INACTIVE_FILE list (suggested by Johannes). The
patchset use the second idea. The reason is LRU_INACTIVE_FILE list is
tiny nowadays and should be full of used once file pages. So we can
still efficiently reclaim MADV_FREE pages there without interference
with other anon and active file pages. Putting the pages into inactive
file list also has an advantage which allows page reclaim to prioritize
MADV_FREE pages and used once file pages. MADV_FREE pages are put into
the lru list and clear SwapBacked flag, so PageAnon(page) &&
!PageSwapBacked(page) will indicate a MADV_FREE pages. These pages will
directly freed without pageout if they are clean, otherwise normal swap
will reclaim them.
For the third issue, the previous post adds global accounting and a
separate RSS count for MADV_FREE pages. The problem is we never get
accurate accounting for MADV_FREE pages. The pages are mapped to
userspace, can be dirtied without notice from kernel side. To get
accurate accounting, we could write protect the page, but then there is
extra page fault overhead, which people don't want to pay. Jemalloc
guys have concerns about the inaccurate accounting, so this post drops
the accounting patches temporarily. The info exported to
/proc/pid/smaps for MADV_FREE pages are kept, which is the only place we
can get accurate accounting right now.
This patch (of 6):
Johannes pointed out TTU_LZFREE is unnecessary. It's true because we
always have the flag set if we want to do an unmap. For cases we don't
do an unmap, the TTU_LZFREE part of code should never run.
Also the TTU_UNMAP is unnecessary. If no other flags set (for example,
TTU_MIGRATION), an unmap is implied.
The patch includes Johannes's cleanup and dead TTU_ACTION macro removal
code
Link: http://lkml.kernel.org/r/4be3ea1bc56b26fd98a54d0a6f70bec63f6d8980.1487965799.git.shli@fb.com
Signed-off-by: Shaohua Li <shli@fb.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NR_PAGES_SCANNED counts number of pages scanned since the last page free
event in the allocator. This was used primarily to measure the
reclaimability of zones and nodes, and determine when reclaim should
give up on them. In that role, it has been replaced in the preceding
patches by a different mechanism.
Being implemented as an efficient vmstat counter, it was automatically
exported to userspace as well. It's however unlikely that anyone
outside the kernel is using this counter in any meaningful way.
Remove the counter and the unused pgdat_reclaimable().
Link: http://lkml.kernel.org/r/20170228214007.5621-8-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jia He <hejianet@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: kswapd spinning on unreclaimable nodes - fixes and
cleanups".
Jia reported a scenario in which the kswapd of a node indefinitely spins
at 100% CPU usage. We have seen similar cases at Facebook.
The kernel's current method of judging its ability to reclaim a node (or
whether to back off and sleep) is based on the amount of scanned pages
in proportion to the amount of reclaimable pages. In Jia's and our
scenarios, there are no reclaimable pages in the node, however, and the
condition for backing off is never met. Kswapd busyloops in an attempt
to restore the watermarks while having nothing to work with.
This series reworks the definition of an unreclaimable node based not on
scanning but on whether kswapd is able to actually reclaim pages in
MAX_RECLAIM_RETRIES (16) consecutive runs. This is the same criteria
the page allocator uses for giving up on direct reclaim and invoking the
OOM killer. If it cannot free any pages, kswapd will go to sleep and
leave further attempts to direct reclaim invocations, which will either
make progress and re-enable kswapd, or invoke the OOM killer.
Patch #1 fixes the immediate problem Jia reported, the remainder are
smaller fixlets, cleanups, and overall phasing out of the old method.
Patch #6 is the odd one out. It's a nice cleanup to get_scan_count(),
and directly related to #5, but in itself not relevant to the series.
If the whole series is too ambitious for 4.11, I would consider the
first three patches fixes, the rest cleanups.
This patch (of 9):
Jia He reports a problem with kswapd spinning at 100% CPU when
requesting more hugepages than memory available in the system:
$ echo 4000 >/proc/sys/vm/nr_hugepages
top - 13:42:59 up 3:37, 1 user, load average: 1.09, 1.03, 1.01
Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.0 us, 12.5 sy, 0.0 ni, 85.5 id, 2.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem: 31371520 total, 30915136 used, 456384 free, 320 buffers
KiB Swap: 6284224 total, 115712 used, 6168512 free. 48192 cached Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
76 root 20 0 0 0 0 R 100.0 0.000 217:17.29 kswapd3
At that time, there are no reclaimable pages left in the node, but as
kswapd fails to restore the high watermarks it refuses to go to sleep.
Kswapd needs to back away from nodes that fail to balance. Up until
commit 1d82de618d ("mm, vmscan: make kswapd reclaim in terms of
nodes") kswapd had such a mechanism. It considered zones whose
theoretically reclaimable pages it had reclaimed six times over as
unreclaimable and backed away from them. This guard was erroneously
removed as the patch changed the definition of a balanced node.
However, simply restoring this code wouldn't help in the case reported
here: there *are* no reclaimable pages that could be scanned until the
threshold is met. Kswapd would stay awake anyway.
Introduce a new and much simpler way of backing off. If kswapd runs
through MAX_RECLAIM_RETRIES (16) cycles without reclaiming a single
page, make it back off from the node. This is the same number of shots
direct reclaim takes before declaring OOM. Kswapd will go to sleep on
that node until a direct reclaimer manages to reclaim some pages, thus
proving the node reclaimable again.
[hannes@cmpxchg.org: check kswapd failure against the cumulative nr_reclaimed count]
Link: http://lkml.kernel.org/r/20170306162410.GB2090@cmpxchg.org
[shakeelb@google.com: fix condition for throttle_direct_reclaim]
Link: http://lkml.kernel.org/r/20170314183228.20152-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20170228214007.5621-2-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Jia He <hejianet@gmail.com>
Tested-by: Jia He <hejianet@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
