NXP LPC SoCs family, which includes LPC18xx/LPC43xx, provides a State
Configurable Timer (SCT) which can be configured as a Pulse Width
Modulator. Other SoCs in that family may share the same hardware.
The PWM supports a total of 16 channels, but only 15 can be simultaneously
requested. There's only one period, global to all the channels, thus PWM
driver will refuse setting different values to it, unless there's only one
channel requested.
Chris Wilson [Tue, 8 Sep 2015 13:17:13 +0000 (14:17 +0100)]
drm/i915: Limit the number of loops for reading a split 64bit register
In I915_READ64_2x32 we attempt to read a 64bit register using 2 32bit
reads. Due to the nature of the registers we try to read in this manner,
they may increment between the two instruction (e.g. a timestamp
counter). To keep the result accurate, we repeat the read if we detect
an overflow (i.e. the upper value varies). However, some hardware is just
plain flaky and may endless loop as the the upper 32bits are not stable.
Just give up after a couple of tries and report whatever we read last.
v2: Use the most recent values when erring out on an unstable register.
When readahead encounters file holes, osd reply returns error -ENOENT,
finish_read() skips adding pages to the the page cache. So readahead
does not work for file holes. The fix is adding zero pages to the
page cache when -ENOENT is returned.
Only ->alloc_msg() should check data_len of the incoming message
against the preallocated ceph_msg, doing it in the messenger is not
right. The contract is that either ->alloc_msg() returns a ceph_msg
which will fit all of the portions of the incoming message, or it
returns NULL and possibly sets skip, signaling whether NULL is due to
an -ENOMEM. ->alloc_msg() should be the only place where we make the
skip/no-skip decision.
I stumbled upon this while looking at con/osd ref counting. Right now,
if we get a non-extent message with a larger data portion than we are
prepared for, ->alloc_msg() returns a ceph_msg, and then, when we skip
it in the messenger, we don't put the con/osd ref acquired in
ceph_con_in_msg_alloc() (which is normally put in process_message()),
so this also fixes a memory leak.
An existing BUG_ON in ceph_msg_data_cursor_init() ensures we don't
corrupt random memory should a buggy ->alloc_msg() return an unfit
ceph_msg.
While at it, I changed the "unknown tid" dout() to a pr_warn() to make
sure all skips are seen and unified format strings.
net: tipc: fix stall during bclink wakeup procedure
If an attempt to wake up users of broadcast link is made when there is
no enough place in send queue than it may hang up inside the
tipc_sk_rcv() function since the loop breaks only after the wake up
queue becomes empty. This can lead to complete CPU stall with the
following message generated by RCU:
The issue occurs only when tipc_sk_rcv() is used to wake up postponed
senders:
tipc_bclink_wakeup_users()
// wakeupq - is a queue which consists of special
// messages with SOCK_WAKEUP type.
tipc_sk_rcv(wakeupq)
...
while (skb_queue_len(inputq)) {
filter_rcv(skb)
// Here the type of message is checked
// and if it is SOCK_WAKEUP then
// it tries to wake up a sender.
tipc_write_space(sk)
wake_up_interruptible_sync_poll()
}
After the sender thread is woke up it can gather control and perform
an attempt to send a message. But if there is no enough place in send
queue it will call link_schedule_user() function which puts a message
of type SOCK_WAKEUP to the wakeup queue and put the sender to sleep.
Thus the size of the queue actually is not changed and the while()
loop never exits.
The approach I proposed is to wake up only senders for which there is
enough place in send queue so the described issue can't occur.
Moreover the same approach is already used to wake up senders on
unicast links.
I have got into the issue on our product code but to reproduce the
issue I changed a benchmark test application (from
tipcutils/demos/benchmark) to perform the following scenario:
1. Run 64 instances of test application (nodes). It can be done
on the one physical machine.
2. Each application connects to all other using TIPC sockets in
RDM mode.
3. When setup is done all nodes start simultaneously send
broadcast messages.
4. Everything hangs up.
The issue is reproducible only when a congestion on broadcast link
occurs. For example, when there are only 8 nodes it works fine since
congestion doesn't occur. Send queue limit is 40 in my case (I use a
critical importance level) and when 64 nodes send a message at the
same moment a congestion occurs every time.
net: dsa: bcm_sf2: Fix ageing conditions and operation
The comparison check between cur_hw_state and hw_state is currently
invalid because cur_hw_state is right shifted by G_MISTP_SHIFT, while
hw_state is not, so we end-up comparing bits 2:0 with bits 7:5, which is
going to cause an additional aging to occur. Fix this by not shifting
cur_hw_state while reading it, but instead, mask the value with the
appropriately shitfted bitmask.
The other problem with the fast-ageing process is that we did not set
the EN_AGE_DYNAMIC bit to request the ageing to occur for dynamically
learned MAC addresses. Finally, write back 0 to the FAST_AGE_CTRL
register to avoid leaving spurious bits sets from one operation to the
other.
Fixes: 12f460f23423 ("net: dsa: bcm_sf2: add HW bridging support") Signed-off-by: Florian Fainelli <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Merge tag 'for-linus-4.3' of git://git.code.sf.net/p/openipmi/linux-ipmi
Pull IPMI updates from Corey Minyard:
"Most of these have been sitting in linux-next for more than a release,
particularly commit 0fbcf4af7c83 ("ipmi: Convert the IPMI SI ACPI
handling to a platform device") which is probably the most complex
patch.
That is also the one that changes drivers/acpi/acpi_pnp.c. The change
in that file is only removing IPMI from a "special platform devices"
list, since I convert it to the standard PNP interface. I posted this
one to the ACPI list twice and got no response, and it seems to work
well in my testing, so I'm hoping it's good.
Hidehiro Kawai posted a set of changes that improves the panic time
handling in the IPMI driver.
The rest of the changes are minor bug fixes or cleanups and some
documentation"
* tag 'for-linus-4.3' of git://git.code.sf.net/p/openipmi/linux-ipmi:
ipmi:ssif: Add a module parm to specify that SMBus alerts don't work
ipmi: add of_device_id in MODULE_DEVICE_TABLE
ipmi: Compensate for BMCs that wont set the irq enable bit
ipmi: Don't call receive handler in the panic context
ipmi: Avoid touching possible corrupted lists in the panic context
ipmi: Don't flush messages in sender() in run-to-completion mode
ipmi: Factor out message flushing procedure
ipmi: Remove unneeded set_run_to_completion call
ipmi: Make some data const that was only read
ipmi: constify SSIF ACPI device ids
ipmi: Delete an unnecessary check before the function call "cleanup_one_si"
char:ipmi - Change 1 to true for bool type variables during initialization.
impi:Remove unneeded setting of module owner to THIS_MODULE in the platform structure, powernv_ipmi_driver
ipmi: Add a comment in how messages are delivered from the lower layer
ipmi/powernv: Fix potential invalid pointer dereference
ipmi: Convert the IPMI SI ACPI handling to a platform device
ipmi: Add device tree bindings information
Merge second patch-bomb from Andrew Morton:
"Almost all of the rest of MM. There was an unusually large amount of
MM material this time"
* emailed patches from Andrew Morton <[email protected]>: (141 commits)
zpool: remove no-op module init/exit
mm: zbud: constify the zbud_ops
mm: zpool: constify the zpool_ops
mm: swap: zswap: maybe_preload & refactoring
zram: unify error reporting
zsmalloc: remove null check from destroy_handle_cache()
zsmalloc: do not take class lock in zs_shrinker_count()
zsmalloc: use class->pages_per_zspage
zsmalloc: consider ZS_ALMOST_FULL as migrate source
zsmalloc: partial page ordering within a fullness_list
zsmalloc: use shrinker to trigger auto-compaction
zsmalloc: account the number of compacted pages
zsmalloc/zram: introduce zs_pool_stats api
zsmalloc: cosmetic compaction code adjustments
zsmalloc: introduce zs_can_compact() function
zsmalloc: always keep per-class stats
zsmalloc: drop unused variable `nr_to_migrate'
mm/memblock.c: fix comment in __next_mem_range()
mm/page_alloc.c: fix type information of memoryless node
memory-hotplug: fix comments in zone_spanned_pages_in_node() and zone_spanned_pages_in_node()
...
Merge branch 'parisc-4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc updates from Helge Deller:
"The most important changes in this patchset are:
- re-enable 64bit PCI bus addresses which were temporarily disabled
for PA-RISC in kernel 4.2
- fix the 64bit CAS operation in the LWS path which now enables us to
enable the 64bit gcc atomic builtins even on 32bit userspace with
64bit kernel
- fix a long-standing bug which sometimes crashed kernel at bootup
while serial interrupt wasn't registered yet"
* 'parisc-4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Use platform_device_register_simple("rtc-generic")
parisc: Drop CONFIG_SMP around update_cr16_clocksource()
parisc: Use double word condition in 64bit CAS operation
parisc: Filter out spurious interrupts in PA-RISC irq handler
parisc: Additionally check for in_atomic() in page fault handler
PCI,parisc: Enable 64-bit bus addresses on PA-RISC
parisc: Define ioremap_uc and ioremap_wc
Merge tag 'linux-kselftest-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest update from Shuah Khan:
"This update adds new zram test and fixes to problems found during
testing this new zram test. In addition, there are a few bug fixes
and ksefltest improvement patches from Linaro developers.
I will send another update later on this week to fix kselftest
breakage due to commit 2bf9e0ab08c6 ("locking/static_keys: Provide a
selftest") after the fix soaks in next for a couple of days"
* tag 'linux-kselftest-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests/zram: Makefile fix
selftests/zram: must be run as root
selftests: breakpoints: fix installing error on the architecture except x86
selftests: check before install
selftests/zram: Adding zram tests
Add suspend frequency support and if needed set it to
the frequency obtained from the suspend opp (can be defined
using opp-v2 bindings and is optional).
cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency
Some cpufreq drivers may set suspend frequency only for
selected setups but still would like to use the generic
suspend handler. Thus don't treat !policy->suspend_freq
condition as an incorrect one.
Merge tag 'iommu-updates-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull iommu updates for from Joerg Roedel:
"This time the IOMMU updates are mostly cleanups or fixes. No big new
features or drivers this time. In particular the changes include:
- Bigger cleanup of the Domain<->IOMMU data structures and the code
that manages them in the Intel VT-d driver. This makes the code
easier to understand and maintain, and also easier to keep the data
structures in sync. It is also a preparation step to make use of
default domains from the IOMMU core in the Intel VT-d driver.
- Fixes for a couple of DMA-API misuses in ARM IOMMU drivers, namely
in the ARM and Tegra SMMU drivers.
- Fix for a potential buffer overflow in the OMAP iommu driver's
debug code
- A couple of smaller fixes and cleanups in various drivers
- One small new feature: Report domain-id usage in the Intel VT-d
driver to easier detect bugs where these are leaked"
* tag 'iommu-updates-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (83 commits)
iommu/vt-d: Really use upper context table when necessary
x86/vt-d: Fix documentation of DRHD
iommu/fsl: Really fix init section(s) content
iommu/io-pgtable-arm: Unmap and free table when overwriting with block
iommu/io-pgtable-arm: Move init-fn declarations to io-pgtable.h
iommu/msm: Use BUG_ON instead of if () BUG()
iommu/vt-d: Access iomem correctly
iommu/vt-d: Make two functions static
iommu/vt-d: Use BUG_ON instead of if () BUG()
iommu/vt-d: Return false instead of 0 in irq_remapping_cap()
iommu/amd: Use BUG_ON instead of if () BUG()
iommu/amd: Make a symbol static
iommu/amd: Simplify allocation in irq_remapping_alloc()
iommu/tegra-smmu: Parameterize number of TLB lines
iommu/tegra-smmu: Factor out tegra_smmu_set_pde()
iommu/tegra-smmu: Extract tegra_smmu_pte_get_use()
iommu/tegra-smmu: Use __GFP_ZERO to allocate zeroed pages
iommu/tegra-smmu: Remove PageReserved manipulation
iommu/tegra-smmu: Convert to use DMA API
iommu/tegra-smmu: smmu_flush_ptc() wants device addresses
...
Merge tag 'regmap-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Pull regmap updates from Mark Brown:
"This has been a busy release for regmap.
By far the biggest set of changes here are those from Markus Pargmann
which implement support for block transfers in smbus devices. This
required quite a bit of refactoring but leaves us better able to
handle odd restrictions that controllers may have and with better
performance on smbus.
Other new features include:
- Fix interactions with lockdep for nested regmaps (eg, when a device
using regmap is connected to a bus where the bus controller has a
separate regmap). Lockdep's default class identification is too
crude to work without help.
- Support for must write bitfield operations, useful for operations
which require writing a bit to trigger them from Kuniori Morimoto.
- Support for delaying during register patch application from Nariman
Poushin.
- Support for overriding cache state via the debugfs implementation
from Richard Fitzgerald"
* tag 'regmap-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap: (25 commits)
regmap: fix a NULL pointer dereference in __regmap_init
regmap: Support bulk reads for devices without raw formatting
regmap-i2c: Add smbus i2c block support
regmap: Add raw_write/read checks for max_raw_write/read sizes
regmap: regmap max_raw_read/write getter functions
regmap: Introduce max_raw_read/write for regmap_bulk_read/write
regmap: Add missing comments about struct regmap_bus
regmap: No multi_write support if bus->write does not exist
regmap: Split use_single_rw internally into use_single_read/write
regmap: Fix regmap_bulk_write for bus writes
regmap: regmap_raw_read return error on !bus->read
regulator: core: Print at debug level on debugfs creation failure
regmap: Fix regmap_can_raw_write check
regmap: fix typos in regmap.c
regmap: Fix integertypes for register address and value
regmap: Move documentation to regmap.h
regmap: Use different lockdep class for each regmap init call
thermal: sti: Add parentheses around bridge->ops->regmap_init call
mfd: vexpress: Add parentheses around bridge->ops->regmap_init call
regmap: debugfs: Fix misuse of IS_ENABLED
...
Merge tag 'fbdev-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux
Pull fbdev updates from Tomi Valkeinen:
"Minor fixes and cleanups"
* tag 'fbdev-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
video: fbdev: atmel_lcdfb: remove useless include
video: fbdev: pxa168fb: Use devm_clk_get
fbdev: ssd1307fb: fix error return code
fbdev: fix snprintf() limit in show_bl_curve()
video: fbdev: s3c-fb: Constify platform_device_id
video: fbdev: atmel: fix warning for const return value
video: fbdev: Drop owner assignment from platform_driver
video: fbdev: Drop owner assignment from i2c_driver
fbdev: remove unnecessary memset in vfb
framebuffer: disable vgacon on microblaze arch
fbdev: udlfb: remove unneeded initialization in few places
fbdev: Allow compile test of GPIO consumers if !GPIOLIB
fbdev: fix cea_modes array size
Aristeu Rozanski [Fri, 12 Jun 2015 19:08:17 +0000 (15:08 -0400)]
sb_edac: correctly fetch DIMM width on Ivy Bridge and Haswell
dimm_dev_type has been incorrectly determined in sb_edac. This patch fixes it
for Ivy Bridge and Haswell only since nothing like exists for Sandy Bridge.
We tested this patch in multiple systems matching the results with the
installed memory modules.
Merge tag 'mmc-v4.3' of git://git.linaro.org/people/ulf.hansson/mmc
Pull MMC updates from Ulf Hansson:
"MMC core:
- Fix a race condition in the request handling
- Skip trim commands for some buggy kingston eMMCs
- An optimization and a correction for erase groups
- Set CMD23 quirk for some Sandisk cards
MMC host:
- sdhci: Give GPIO CD higher precedence and don't poll when it's used
- sdhci: Fix DMA memory leakage
- sdhci: Some updates for clock management
- sdhci-of-at91: introduce driver for the Atmel SDMMC
- sdhci-of-arasan: Add support for sdhci-5.1
- sdhci-esdhc-imx: Add support for imx7d which also supports HS400
- sdhci: A collection of fixes and improvements for various sdhci hosts
- omap_hsmmc: Modernization of the regulator code
- dw_mmc: A couple of fixes for DMA and PIO mode
- usdhi6rol0: A few fixes and support probe deferral for regulators
- pxamci: Convert to use dmaengine
- sh_mmcif: Fix the suspend process in a short term solution
- tmio: Adjust timeout for commands
- sunxi: Fix timeout while gating/ungating clock"
* tag 'mmc-v4.3' of git://git.linaro.org/people/ulf.hansson/mmc: (67 commits)
mmc: android-goldfish: remove incorrect __iomem annotation
mmc: core: fix race condition in mmc_wait_data_done
mmc: host: omap_hsmmc: remove CONFIG_REGULATOR check
mmc: host: omap_hsmmc: use ios->vdd for setting vmmc voltage
mmc: host: omap_hsmmc: use regulator_is_enabled to find pbias status
mmc: host: omap_hsmmc: enable/disable vmmc_aux regulator based on previous state
mmc: host: omap_hsmmc: don't use ->set_power to set initial regulator state
mmc: host: omap_hsmmc: avoid pbias regulator enable on power off
mmc: host: omap_hsmmc: add separate function to set pbias
mmc: host: omap_hsmmc: add separate functions for enable/disable supply
mmc: host: omap_hsmmc: return error if any of the regulator APIs fail
mmc: host: omap_hsmmc: remove unnecessary pbias set_voltage
mmc: host: omap_hsmmc: use mmc_host's vmmc and vqmmc
mmc: host: omap_hsmmc: use the ocrmask provided by the vmmc regulator
mmc: host: omap_hsmmc: cleanup omap_hsmmc_reg_get()
mmc: host: omap_hsmmc: return on fatal errors from omap_hsmmc_reg_get
mmc: host: omap_hsmmc: use devm_regulator_get_optional() for vmmc
mmc: sdhci-of-at91: fix platform_no_drv_owner.cocci warnings
mmc: sh_mmcif: Fix suspend process
mmc: usdhi6rol0: fix error return code
...
Aristeu Rozanski [Fri, 12 Jun 2015 13:44:52 +0000 (09:44 -0400)]
sb_edac: look harder for DDRIO on Haswell systems
In case the memory banks are populated so the first channel isn't used, the
DDRIO PCI device won't be visible and it won't be possible to determine the
memory type.
Merge tag 'platform-drivers-x86-v4.3-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86
Pull x86 platform driver updates from Darren Hart:
"Significant work on toshiba_acpi, including new hardware support,
refactoring, and cleanups. Extend device support for asus, ideapad,
and acer systems. New surface pro 3 buttons driver. Misc minor
cleanups for thinkpad and hp-wireless.
acer-wmi:
- No rfkill on HP Omen 15 wifi
thinkpad_acpi:
- Remove side effects from vdbg_printk -> no_printk macro
surface pro 3:
- Add support driver for Surface Pro 3 buttons
hp-wireless:
- remove unneeded goto/label in hpwl_init
ideapad-laptop:
- add alternative representation for Yoga 2 to DMI table
- Add Lenovo Yoga 3 14 to no_hw_rfkill dmi list
asus-laptop:
- Add key found on Asus F3M
MAINTAINERS:
- Remove Toshiba Linux mailing list address
toshiba_acpi:
- Bump driver version to 0.23
- Remove unnecessary checks and returns in HCI/SCI functions
- Refactor *{get, set} functions return value
- Remove "*not supported" feature prints
- Change *available functions return type
- Add set_fan_status function
- Change some variables to avoid warnings from ninja-check
- Reorder toshiba_acpi_alt_keymap entries
- Remove unused wireless defines
- Transflective backlight updates
- Avoid registering input device on WMI event laptops
- Add /dev/toshiba_acpi device
- Adapt /proc/acpi/toshiba/keys to TOS1900 devices"
* tag 'platform-drivers-x86-v4.3-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86: (21 commits)
acer-wmi: No rfkill on HP Omen 15 wifi
thinkpad_acpi: Remove side effects from vdbg_printk -> no_printk macro
surface pro 3: Add support driver for Surface Pro 3 buttons
hp-wireless: remove unneeded goto/label in hpwl_init
ideapad-laptop: add alternative representation for Yoga 2 to DMI table
asus-laptop: Add key found on Asus F3M
MAINTAINERS: Remove Toshiba Linux mailing list address
ideapad-laptop: Add Lenovo Yoga 3 14 to no_hw_rfkill dmi list
toshiba_acpi: Bump driver version to 0.23
toshiba_acpi: Remove unnecessary checks and returns in HCI/SCI functions
toshiba_acpi: Refactor *{get, set} functions return value
toshiba_acpi: Remove "*not supported" feature prints
toshiba_acpi: Change *available functions return type
toshiba_acpi: Add set_fan_status function
toshiba_acpi: Change some variables to avoid warnings from ninja-check
toshiba_acpi: Reorder toshiba_acpi_alt_keymap entries
toshiba_acpi: Remove unused wireless defines
toshiba_acpi: Transflective backlight updates
toshiba_acpi: Avoid registering input device on WMI event laptops
toshiba_acpi: Add /dev/toshiba_acpi device
...
Merge branch 'i2c/for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"Features:
- new drivers: Renesas EMEV2, register based MUX, NXP LPC2xxx
- core: scans DT and assigns wakeup interrupts. no driver changes needed.
- core: some refcouting issues fixed and better API for that
- core: new helper function for best effort block read emulation
- slave framework: proper DT bindings and userspace instantiation
- some bigger work for xiic, pxa, omap drivers
.. and quite a number of smaller driver fixes, cleanups, improvements"
* 'i2c/for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (65 commits)
i2c: mux: reg Change ioread endianness for readback
i2c: mux: reg: fix compilation warnings
i2c: mux: reg: simplify register size checking
i2c: muxes: fix leaked i2c adapter device node references
i2c: allow specifying separate wakeup interrupt in device tree
of/irq: export of_get_irq_byname()
i2c: xgene-slimpro: dma_mapping_error() doesn't return an error code
i2c: Replace I2C_CROS_EC_TUNNEL dependency
eeprom: at24: use i2c_smbus_read_i2c_block_data_or_emulated
i2c: core: Add support for best effort block read emulation
i2c: lpc2k: add driver
i2c: mux: Add register-based mux i2c-mux-reg
i2c: dt: describe generic bindings
i2c: slave: print warning if slave flag not set
i2c: support 10 bit and slave addresses in sysfs 'new_device'
i2c: take address space into account when checking for used addresses
i2c: apply DT flags when probing
i2c: make address check indpendent from client struct
i2c: rename address check functions
i2c: apply address offset for slaves, too
...
Merge tag 'rtc-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
"Core:
- use is_visible() to control sysfs attributes
- switch wakealarm attribute to DEVICE_ATTR_RW
- make rtc_does_wakealarm() return boolean
- properly manage lifetime of dev and cdev in rtc device
- remove unnecessary device_get() in rtc_device_unregister
- fix double free in rtc_register_device() error path
Subsystem wide cleanups:
- fix drivers that consider 0 as a valid IRQ in client->irq
- Drop (un)likely before IS_ERR(_OR_NULL)
- drop the remaining owner assignment for i2c_driver and
platform_driver
- module autoload fixes
Drivers:
- 88pm80x: add device tree support
- abx80x: fix RTC write bit
- ab8500: Add a sentinel to ab85xx_rtc_ids[]
- armada38x: Align RTC set time procedure with the official errata
- as3722: correct month value
- at91sam9: cleanups
- at91rm9200: get and use slow clock and cleanups
- bq32k: remove redundant check
- cmos: century support, proper fix for the spurious wakeup
- ds1307: cleanups and wakeup irq support
- ds1374: Remove unused variable
- ds1685: Use module_platform_driver
- ds3232: fix WARNING trace in resume function
- gemini: fix ptr_ret.cocci warnings
- mt6397: implement suspend/resume
- omap: support internal and external clock enabling
- opal: Enable alarms only when opal supports tpo
- pcf2127: use OFS flag to detect unreliable date and warn the user
- pl031: fix typo for author email
- rx8025: huge cleanup and fixes
- sa1100/pxa: share common code
- s5m: fix to update ctrl register
- s3c: fix clocks and wakeup, cleanup
- sirfsoc: use regmap
- nvram_read()/nvram_write() functions for cmos, ds1305, ds1307,
ds1343, ds1511, ds1553, ds1742, m48t59, rp5c01, stk17ta8, tx4939
- use rtc_valid_tm() error code when reading date/time instead of 0
for isl12022, pcf2123, pcf2127"
* tag 'rtc-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (90 commits)
rtc: abx80x: fix RTC write bit
rtc: ab8500: Add a sentinel to ab85xx_rtc_ids[]
rtc: ds1374: Remove unused variable
rtc: Fix module autoload for OF platform drivers
rtc: Fix module autoload for rtc-{ab8500,max8997,s5m} drivers
rtc: omap: Add external clock enabling support
rtc: omap: Add internal clock enabling support
ARM: dts: AM437x: Add the internal and external clock nodes for rtc
rtc: s5m: fix to update ctrl register
rtc: add xilinx zynqmp rtc driver
devicetree: bindings: rtc: add bindings for xilinx zynqmp rtc
rtc: as3722: correct month value
ARM: config: Switch PXA27x platforms to use PXA RTC driver
ARM: mmp: remove unused RTC register definitions
ARM: sa1100: remove unused RTC register definitions
rtc: sa1100/pxa: convert to run-time register mapping
ARM: pxa: add memory resource to SA1100 RTC device
rtc: pxa: convert to use shared sa1100 functions
rtc: sa1100: prepare to share sa1100_rtc_ops
rtc: ds3232: fix WARNING trace in resume function
...
zswap_get_swap_cache_page and read_swap_cache_async have pretty much the
same code with only significant difference in return value and usage of
swap_readpage.
I a helper __read_swap_cache_async() with the common code. Behavior
change: now zswap_get_swap_cache_page will use radix_tree_maybe_preload
instead radix_tree_preload. Looks like, this wasn't changed only by the
reason of code duplication.
Make zram syslog error reporting more consistent. We have random
error levels in some places. For example, critical errors like
"Error allocating memory for compressed page"
and
"Unable to allocate temp memory"
are reported as KERN_INFO messages.
a) Reassign error levels
Error messages that directly affect zram
functionality -- pr_err():
Error allocating zram address table
Error creating memory pool
Decompression failed! err=%d, page=%u
Unable to allocate temp memory
Compression failed! err=%d
Error allocating memory for compressed page: %u, size=%zu
Cannot initialise %s compressing backend
Error allocating disk queue for device %d
Error allocating disk structure for device %d
Error creating sysfs group for device %d
Unable to register zram-control class
Unable to get major number
Messages that do not affect functionality, but user
must be warned (because sysfs attrs will be removed in
this particular case) -- pr_warn():
%d (%s) Attribute %s (and others) will be removed. %s
Messages that do not affect functionality and mostly are
informative -- pr_info():
Cannot change max compression streams
Can't change algorithm for initialized device
Cannot change disksize for initialized device
Added device: %s
Removed device: %s
b) Update sysfs_create_group() error message
First, it lacks a trailing new line; add it. Second, every error message
in zram_add() has a "for device %d" part, which makes errors more
informative. Add missing part to "Error creating sysfs group" message.
zsmalloc: do not take class lock in zs_shrinker_count()
We can avoid taking class ->lock around zs_can_compact() in
zs_shrinker_count(), because the number that we return back is outdated
in general case, by design. We have different sources that are able to
change class's state right after we return from zs_can_compact() --
ongoing I/O operations, manually triggered compaction, or two of them
happening simultaneously.
We re-do this calculations during compaction on a per class basis
anyway.
zs_unregister_shrinker() will not return until we have an active
shrinker, so classes won't unexpectedly disappear while
zs_shrinker_count() iterates them.
zsmalloc: partial page ordering within a fullness_list
We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY}
pages. Put a page with higher ->inuse count first within its
->fullness_list, which will give us better chances to fill up this page
with new objects (find_get_zspage() return ->fullness_list head for new
object allocation), so some zspages will become ZS_ALMOST_FULL/ZS_FULL
quicker.
It performs a trivial and cheap ->inuse compare which does not slow down
zsmalloc and in the worst case keeps the list pages in no particular
order.
A more expensive solution could sort fullness_list by ->inuse count.
Perform automatic pool compaction by a shrinker when system is getting
tight on memory.
User-space has a very little knowledge regarding zsmalloc fragmentation
and basically has no mechanism to tell whether compaction will result in
any memory gain. Another issue is that user space is not always aware
of the fact that system is getting tight on memory. Which leads to very
uncomfortable scenarios when user space may start issuing compaction
'randomly' or from crontab (for example). Fragmentation is not always
necessarily bad, allocated and unused objects, after all, may be filled
with the data later, w/o the need of allocating a new zspage. On the
other hand, we obviously don't want to waste memory when the system
needs it.
Compaction now has a relatively quick pool scan so we are able to
estimate the number of pages that will be freed easily, which makes it
possible to call this function from a shrinker->count_objects()
callback. We also abort compaction as soon as we detect that we can't
free any pages any more, preventing wasteful objects migrations.
Compaction returns back to zram the number of migrated objects, which is
quite uninformative -- we have objects of different sizes so user space
cannot obtain any valuable data from that number. Change compaction to
operate in terms of pages and return back to compaction issuer the
number of pages that were freed during compaction. So from now on we
will export more meaningful value in zram<id>/mm_stat -- the number of
freed (compacted) pages.
This requires:
(a) a rename of `num_migrated' to 'pages_compacted'
(b) a internal API change -- return first_page's fullness_group from
putback_zspage(), so we know when putback_zspage() did
free_zspage(). It helps us to account compaction stats correctly.
`zs_compact_control' accounts the number of migrated objects but it has
a limited lifespan -- we lose it as soon as zs_compaction() returns back
to zram. It worked fine, because (a) zram had it's own counter of
migrated objects and (b) only zram could trigger compaction. However,
this does not work for automatic pool compaction (not issued by zram).
To account objects migrated during auto-compaction (issued by the
shrinker) we need to store this number in zs_pool.
Define a new `struct zs_pool_stats' structure to keep zs_pool's stats
there. It provides only `num_migrated', as of this writing, but it
surely can be extended.
A new zsmalloc zs_pool_stats() symbol exports zs_pool's stats back to
caller.
Use zs_pool_stats() in zram and remove `num_migrated' from zram_stats.
Change zs_object_copy() argument order to be (DST, SRC) rather than
(SRC, DST). copy/move functions usually have (to, from) arguments
order.
Rename alloc_target_page() to isolate_target_page(). This function
doesn't allocate anything, it isolates target page, pretty much like
isolate_source_page().
This function checks if class compaction will free any pages.
Rephrasing -- do we have enough unused objects to form at least one
ZS_EMPTY page and free it. It aborts compaction if class compaction
will not result in any (further) savings.
EXAMPLE (this debug output is not part of this patch set):
- class size
- number of allocated objects
- number of used objects
- max objects per zspage
- pages per zspage
- estimated number of pages that will be freed
Every "compaction is useless" indicates that we saved CPU cycles.
class-512 has
544 object allocated
540 objects used
8 objects per-page
Even if we have a ALMOST_EMPTY zspage, we still don't have enough room to
migrate all of its objects and free this zspage; so compaction will not
make a lot of sense, it's better to just leave it as is.
Always account per-class `zs_size_stat' stats. This data will help us
make better decisions during compaction. We are especially interested
in OBJ_ALLOCATED and OBJ_USED, which can tell us if class compaction
will result in any memory gain.
For instance, we know the number of allocated objects in the class, the
number of objects being used (so we also know how many objects are not
used) and the number of objects per-page. So we can ensure if we have
enough unused objects to form at least one ZS_EMPTY zspage during
compaction.
We calculate this value on per-class basis so we can calculate a total
number of zspages that can be released. Which is exactly what a
shrinker wants to know.
This patchset tweaks compaction and makes it possible to trigger pool
compaction automatically when system is getting low on memory.
zsmalloc in some cases can suffer from a notable fragmentation and
compaction can release some considerable amount of memory. The problem
here is that currently we fully rely on user space to perform compaction
when needed. However, performing zsmalloc compaction is not always an
obvious thing to do. For example, suppose we have a `idle' fragmented
(compaction was never performed) zram device and system is getting low
on memory due to some 3rd party user processes (gcc LTO, or firefox,
etc.). It's quite unlikely that user space will issue zpool compaction
in this case. Besides, user space cannot tell for sure how badly pool
is fragmented; however, this info is known to zsmalloc and, hence, to a
shrinker.
This patch (of 7):
__zs_compact() does not use `nr_to_migrate', drop it.
memory-hotplug: fix comments in zone_spanned_pages_in_node() and zone_spanned_pages_in_node()
When hot adding a node from add_memory(), we will add memblock first, so
the node is not empty. But when called from cpu_up(), the node should
be empty.
Yaowei Bai [Tue, 8 Sep 2015 22:04:13 +0000 (15:04 -0700)]
mm/page_alloc.c: change sysctl_lower_zone_reserve_ratio to sysctl_lowmem_reserve_ratio in comments
We use sysctl_lowmem_reserve_ratio rather than
sysctl_lower_zone_reserve_ratio to determine how aggressive the kernel
is in defending lowmem from the possibility of being captured into
pinned user memory. To avoid misleading, correct it in some comments.
Yaowei Bai [Tue, 8 Sep 2015 22:04:10 +0000 (15:04 -0700)]
mm/page_alloc.c: fix a misleading comment
The comment says that the per-cpu batchsize and zone watermarks are
determined by present_pages which is definitely wrong, they are both
calculated from managed_pages. Fix it.
Petr Mladek [Tue, 8 Sep 2015 22:04:05 +0000 (15:04 -0700)]
mm/khugepaged: allow interruption of allocation sleep again
Commit 1dfb059b9438 ("thp: reduce khugepaged freezing latency") fixed
khugepaged to do not block a system suspend. But the result is that it
could not get interrupted before the given timeout because the condition
for the wait event is "false".
This patch puts back the original approach but it uses
freezable_schedule_timeout_interruptible() instead of
schedule_timeout_interruptible(). It does the right thing. I am pretty
sure that the freezable variant was not used in the original fix only
because it was not available at that time.
The regression has been there for ages. It was not critical. It just
did the allocation throttling a little bit more aggressively.
I found this problem when converting the kthread to kthread worker API
and trying to understand the code.
This bug is thought to have minimal userspace-visible impact. Somebody
could set a high alloc_sleep value by mistake, and then try to fix it
back, but khugepaged would keep sleeping until the high value expires.
Joonsoo Kim [Tue, 8 Sep 2015 22:03:59 +0000 (15:03 -0700)]
mm/compaction: correct to flush migrated pages if pageblock skip happens
We cache isolate_start_pfn before entering isolate_migratepages(). If
pageblock is skipped in isolate_migratepages() due to whatever reason,
cc->migrate_pfn can be far from isolate_start_pfn hence we flush pages
that were freed. For example, the following scenario can be possible:
- assume order-9 compaction, pageblock order is 9
- start_isolate_pfn is 0x200
- isolate_migratepages()
- skip a number of pageblocks
- start to isolate from pfn 0x600
- cc->migrate_pfn = 0x620
- return
- last_migrated_pfn is set to 0x200
- check flushing condition
- current_block_start is set to 0x600
- last_migrated_pfn < current_block_start then do useless flush
This wrong flush would not help the performance and success rate so this
patch tries to fix it. One simple way to know the exact position where
we start to isolate migratable pages is that we cache it in
isolate_migratepages() before entering actual isolation. This patch
implements that and fixes the problem.
alloc_pages_node() might fail when called with NUMA_NO_NODE and
__GFP_THISNODE on a CPU belonging to a memoryless node. To make the
local-node fallback more robust and prevent such situations, use
numa_mem_id(), which was introduced for similar scenarios in the slab
context.
mm: unify checks in alloc_pages_node() and __alloc_pages_node()
Perform the same debug checks in alloc_pages_node() as are done in
__alloc_pages_node(), by making the former function a wrapper of the
latter one.
In addition to better diagnostics in DEBUG_VM builds for situations
which have been already fatal (e.g. out-of-bounds node id), there are
two visible changes for potential existing buggy callers of
alloc_pages_node():
- calling alloc_pages_node() with any negative nid (e.g. due to arithmetic
overflow) was treated as passing NUMA_NO_NODE and fallback to local node was
applied. This will now be fatal.
- calling alloc_pages_node() with an offline node will now be checked for
DEBUG_VM builds. Since it's not fatal if the node has been previously online,
and this patch may expose some existing buggy callers, change the VM_BUG_ON
in __alloc_pages_node() to VM_WARN_ON.
mm: rename alloc_pages_exact_node() to __alloc_pages_node()
alloc_pages_exact_node() was introduced in commit 6484eb3e2a81 ("page
allocator: do not check NUMA node ID when the caller knows the node is
valid") as an optimized variant of alloc_pages_node(), that doesn't
fallback to current node for nid == NUMA_NO_NODE. Unfortunately the
name of the function can easily suggest that the allocation is
restricted to the given node and fails otherwise. In truth, the node is
only preferred, unless __GFP_THISNODE is passed among the gfp flags.
The misleading name has lead to mistakes in the past, see for example
commits 5265047ac301 ("mm, thp: really limit transparent hugepage
allocation to local node") and b360edb43f8e ("mm, mempolicy:
migrate_to_node should only migrate to node").
Another issue with the name is that there's a family of
alloc_pages_exact*() functions where 'exact' means exact size (instead
of page order), which leads to more confusion.
To prevent further mistakes, this patch effectively renames
alloc_pages_exact_node() to __alloc_pages_node() to better convey that
it's an optimized variant of alloc_pages_node() not intended for general
usage. Both functions get described in comments.
It has been also considered to really provide a convenience function for
allocations restricted to a node, but the major opinion seems to be that
__GFP_THISNODE already provides that functionality and we shouldn't
duplicate the API needlessly. The number of users would be small
anyway.
Existing callers of alloc_pages_exact_node() are simply converted to
call __alloc_pages_node(), with the exception of sba_alloc_coherent()
which open-codes the check for NUMA_NO_NODE, so it is converted to use
alloc_pages_node() instead. This means it no longer performs some
VM_BUG_ON checks, and since the current check for nid in
alloc_pages_node() uses a 'nid < 0' comparison (which includes
NUMA_NO_NODE), it may hide wrong values which would be previously
exposed.
Both differences will be rectified by the next patch.
To sum up, this patch makes no functional changes, except temporarily
hiding potentially buggy callers. Restricting the checks in
alloc_pages_node() is left for the next patch which can in turn expose
more existing buggy callers.
mm, vmscan: unlock page while waiting on writeback
This is merely a politeness: I've not found that shrink_page_list()
leads to deadlock with the page it holds locked across
wait_on_page_writeback(); but nevertheless, why hold others off by
keeping the page locked there?
And while we're at it: remove the mistaken "not " from the commentary on
this Case 3 (and a distracting blank line from Case 2, if I may).
Wang Kai [Tue, 8 Sep 2015 22:03:41 +0000 (15:03 -0700)]
kmemleak: record accurate early log buffer count and report when exceeded
In log_early function, crt_early_log should also count once when
'crt_early_log >= ARRAY_SIZE(early_log)'. Otherwise the reported count
from kmemleak_init is one less than 'actual number'.
Then, in kmemleak_init, if early_log buffer size equal actual number,
kmemleak will init sucessful, so change warning condition to
'crt_early_log > ARRAY_SIZE(early_log)'.
Shmem uses shmem_recalc_inode to update i_blocks when it allocates page,
undoes range or swaps. But mm can drop clean page without notifying
shmem. This makes fstat sometimes return out-of-date block size.
The problem can be partially solved when we add
inode_operations->getattr which calls shmem_recalc_inode to update
i_blocks for fstat.
shmem_recalc_inode also updates counter used by statfs and
vm_committed_as. For them the situation is not changed. They still
suffer from the discrepancy after dropping clean page and before the
function is called by aforementioned triggers.
mm/memblock.c: rename local variable of memblock_type to 'type'
Since commit e3239ff92a17 ("memblock: Rename memblock_region to
memblock_type and memblock_property to memblock_region"), all local
variables of the membock_type type were renamed to 'type'. This commit
renames all remaining local variables with the memblock_type type to the
same view.
mm/hwpoison: don't try to unpoison containment-failed pages
memory_failure() can be called at any page at any time, which means that
we can't eliminate the possibility of containment failure. In such case
the best option is to leak the page intentionally (and never touch it
later.)
We have an unpoison function for testing, and it cannot handle such
containment-failed pages, which results in kernel panic (visible with
various calltraces.) So this patch suggests that we limit the
unpoisonable pages to properly contained pages and ignore any other
ones.
Testers are recommended to keep in mind that there're un-unpoisonable
pages when writing test programs.
soft_offline_page
__soft_offline_page
TestSetPageHWPoison
unpoison_memory
PageHWPoison check (true)
TestClearPageHWPoison
put_page -> release refcount held by get_hwpoison_page in unpoison_memory
put_page -> release refcount held by isolate_lru_page in __soft_offline_page
migrate_pages
The second put_page() releases refcount held by isolate_lru_page() which
will lead to unmap_and_move() releases the last refcount of page and w/
mapcount still 1 since try_to_unmap() is not called if there is only one
user map the page. Anyway, the page refcount and mapcount will still
mess if the page is mapped by multiple users.
This race was introduced by commit 4491f71260 ("mm/memory-failure: set
PageHWPoison before migrate_pages()"), which focuses on preventing the
reuse of successfully migrated page. Before this commit we prevent the
reuse by changing the migratetype to MIGRATE_ISOLATE during soft
offlining, which has the following problems, so simply reverting the
commit is not a best option:
1) it doesn't eliminate the reuse completely, because
set_migratetype_isolate() can fail to set MIGRATE_ISOLATE to the
target page if the pageblock of the page contains one or more
unmovable pages (i.e. has_unmovable_pages() returns true).
2) the original code changes migratetype to MIGRATE_ISOLATE
forcibly, and sets it to MIGRATE_MOVABLE forcibly after soft offline,
regardless of the original migratetype state, which could impact
other subsystems like memory hotplug or compaction.
This patch moves PageSetHWPoison just after put_page() in
unmap_and_move(), which closes up the reported race window and minimizes
another race window b/w SetPageHWPoison and reallocation (which causes
the reuse of soft-offlined page.) The latter race window still exists
but it's acceptable, because it's rare and effectively the same as
ordinary "containment failure" case even if it happens, so keep the
window open is acceptable.
Wanpeng Li [Tue, 8 Sep 2015 22:03:18 +0000 (15:03 -0700)]
mm/hwpoison: fix refcount of THP head page in no-injection case
Hwpoison injection takes a refcount of target page and another refcount
of head page of THP if the target page is the tail page of a THP.
However, current code doesn't release the refcount of head page if the
THP is not supported to be injected wrt hwpoison filter.
Fix it by reducing the refcount of head page if the target page is the
tail page of a THP and it is not supported to be injected.
Mark Salter [Tue, 8 Sep 2015 22:03:04 +0000 (15:03 -0700)]
arm64: support initrd outside kernel linear map
The use of mem= could leave part or all of the initrd outside of the
kernel linear map. This will lead to an error when unpacking the initrd
and a probable failure to boot. This patch catches that situation and
relocates the initrd to be fully within the linear map.
Mark Salter [Tue, 8 Sep 2015 22:03:01 +0000 (15:03 -0700)]
mm: add utility for early copy from unmapped ram
When booting an arm64 kernel w/initrd using UEFI/grub, use of mem= will
likely cut off part or all of the initrd. This leaves it outside the
kernel linear map which leads to failure when unpacking. The x86 code
has a similar need to relocate an initrd outside of mapped memory in
some cases.
The current x86 code uses early_memremap() to copy the original initrd
from unmapped to mapped RAM. This patchset creates a generic
copy_from_early_mem() utility based on that x86 code and has arm64 and
x86 share it in their respective initrd relocation code.
This patch (of 3):
In some early boot circumstances, it may be necessary to copy from RAM
outside the kernel linear mapping to mapped RAM. The need to relocate
an initrd is one example in the x86 code. This patch creates a helper
function based on current x86 code.
Mike Kravetz [Tue, 8 Sep 2015 22:02:52 +0000 (15:02 -0700)]
Revert "selftests: add hugetlbfstest"
This manually reverts 7e50533d4b842 ("selftests: add hugetlbfstest").
The hugetlbfstest test depends on hugetlb pages being counted in a
task's rss. This functionality is not in the kernel, so the test will
always fail. Remove test to avoid confusion.
mm, compaction: skip compound pages by order in free scanner
The compaction free scanner is looking for PageBuddy() pages and
skipping all others. For large compound pages such as THP or hugetlbfs,
we can save a lot of iterations if we skip them at once using their
compound_order(). This is generally unsafe and we can read a bogus
value of order due to a race, but if we are careful, the only danger is
skipping too much.
When tested with stress-highalloc from mmtests on 4GB system with 1GB
hugetlbfs pages, the vmstat compact_free_scanned count decreased by at
least 15%.
mm, compaction: always skip all compound pages by order in migrate scanner
The compaction migrate scanner tries to skip THP pages by their order,
to reduce number of iterations for pages it cannot isolate. The check
is only done if PageLRU() is true, which means it applies to THP pages,
but not e.g. hugetlbfs pages or any other non-LRU compound pages, which
we have to iterate by base pages.
This limitation comes from the assumption that it's only safe to read
compound_order() when we have the zone's lru_lock and THP cannot be
split under us. But the only danger (after filtering out order values
that are not below MAX_ORDER, to prevent overflows) is that we skip too
much or too little after reading a bogus compound_order() due to a rare
race. This is the same reasoning as patch 99c0fd5e51c4 ("mm,
compaction: skip buddy pages by their order in the migrate scanner")
introduced for unsafely reading PageBuddy() order.
After this patch, all pages are tested for PageCompound() and we skip
them by compound_order(). The test is done after the test for
balloon_page_movable() as we don't want to assume if balloon pages (or
other pages with own isolation and migration implementation if a generic
API gets implemented) are compound or not.
When tested with stress-highalloc from mmtests on 4GB system with 1GB
hugetlbfs pages, the vmstat compact_migrate_scanned count decreased by
15%.
mm, compaction: encapsulate resetting cached scanner positions
Reseting the cached compaction scanner positions is now open-coded in
__reset_isolation_suitable() and compact_finished(). Encapsulate the
functionality in a new function reset_cached_positions().
mm, compaction: simplify handling restart position in free pages scanner
Handling the position where compaction free scanner should restart
(stored in cc->free_pfn) got more complex with commit e14c720efdd7 ("mm,
compaction: remember position within pageblock in free pages scanner").
Currently the position is updated in each loop iteration of
isolate_freepages(), although it should be enough to update it only when
breaking from the loop. There's also an extra check outside the loop
updates the position in case we have met the migration scanner.
This can be simplified if we move the test for having isolated enough
from the for-loop header next to the test for contention, and
determining the restart position only in these cases. We can reuse the
isolate_start_pfn variable for this instead of setting cc->free_pfn
directly. Outside the loop, we can simply set cc->free_pfn to current
value of isolate_start_pfn without any extra check.
Also add a VM_BUG_ON to catch possible mistake in the future, in case we
later add a new condition that terminates isolate_freepages_block()
prematurely without also considering the condition in
isolate_freepages().
mm, compaction: more robust check for scanners meeting
Assorted compaction cleanups and optimizations. The interesting patches
are 4 and 5. In 4, skipping of compound pages in single iteration is
improved for migration scanner, so it works also for !PageLRU compound
pages such as hugetlbfs, slab etc. Patch 5 introduces this kind of
skipping in the free scanner. The trick is that we can read
compound_order() without any protection, if we are careful to filter out
values larger than MAX_ORDER. The only danger is that we skip too much.
The same trick was already used for reading the freepage order in the
migrate scanner.
To demonstrate improvements of Patches 4 and 5 I've run stress-highalloc
from mmtests, set to simulate THP allocations (including __GFP_COMP) on
a 4GB system where 1GB was occupied by hugetlbfs pages. I'll include
just the relevant stats:
With 5 iterations per patch, the results are still noisy, but we can see
that Patch 4 does reduce migrate_scanned by 15% thanks to skipping the
hugetlbfs pages at once. Interestingly, free_scanned is also reduced
and I have no idea why. Patch 5 further reduces free_scanned as
expected, by 15%. Other stats are unaffected modulo noise.
[1] https://lkml.org/lkml/2015/1/19/158
This patch (of 5):
Compaction should finish when the migration and free scanner meet, i.e.
they reach the same pageblock. Currently however, the test in
compact_finished() simply just compares the exact pfns, which may yield
a false negative when the free scanner position is in the middle of a
pageblock and the migration scanner reaches the begining of the same
pageblock.
This hasn't been a problem until commit e14c720efdd7 ("mm, compaction:
remember position within pageblock in free pages scanner") allowed the
free scanner position to be in the middle of a pageblock between
invocations. The hot-fix 1d5bfe1ffb5b ("mm, compaction: prevent
infinite loop in compact_zone") prevented the issue by adding a special
check in the migration scanner to satisfy the current detection of
scanners meeting.
However, the proper fix is to make the detection more robust. This
patch introduces the compact_scanners_met() function that returns true
when the free scanner position is in the same or lower pageblock than
the migration scanner. The special case in isolate_migratepages()
introduced by 1d5bfe1ffb5b is removed.
Sean O. Stalley [Tue, 8 Sep 2015 22:02:24 +0000 (15:02 -0700)]
mm: add support for __GFP_ZERO flag to dma_pool_alloc()
Currently a call to dma_pool_alloc() with a ___GFP_ZERO flag returns a
non-zeroed memory region.
This patchset adds support for the __GFP_ZERO flag to dma_pool_alloc(),
adds 2 wrapper functions for allocing zeroed memory from a pool, and
provides a coccinelle script for finding & replacing instances of
dma_pool_alloc() followed by memset(0) with a single dma_pool_zalloc()
call.
There was some concern that this always calls memset() to zero, instead
of passing __GFP_ZERO into the page allocator.
[https://lkml.org/lkml/2015/7/15/881]
I ran a test on my system to get an idea of how often dma_pool_alloc()
calls into pool_alloc_page().
After Boot: [ 30.119863] alloc_calls:541, page_allocs:7
After an hour: [ 3600.951031] alloc_calls:9566, page_allocs:12
After copying 1GB file onto a USB drive:
[ 4260.657148] alloc_calls:17225, page_allocs:12
It doesn't look like dma_pool_alloc() calls down to the page allocator
very often (at least on my system).
This patch (of 4):
Currently the __GFP_ZERO flag is ignored by dma_pool_alloc().
Make dma_pool_alloc() zero the memory if this flag is set.
Jaewon Kim [Tue, 8 Sep 2015 22:02:21 +0000 (15:02 -0700)]
vmscan: fix increasing nr_isolated incurred by putback unevictable pages
reclaim_clean_pages_from_list() assumes that shrink_page_list() returns
number of pages removed from the candidate list. But shrink_page_list()
puts back mlocked pages without passing it to caller and without
counting as nr_reclaimed. This increases nr_isolated.
To fix this, this patch changes shrink_page_list() to pass unevictable
pages back to caller. Caller will take care those pages.
Minchan said:
It fixes two issues.
1. With unevictable page, cma_alloc will be successful.
Exactly speaking, cma_alloc of current kernel will fail due to
unevictable pages.
2. fix leaking of NR_ISOLATED counter of vmstat
With it, too_many_isolated works. Otherwise, it could make hang until
the process get SIGKILL.
mm: vmscan: never isolate more pages than necessary
If transparent huge pages are enabled, we can isolate many more pages
than we actually need to scan, because we count both single and huge
pages equally in isolate_lru_pages().
Since commit 5bc7b8aca942d ("mm: thp: add split tail pages to shrink
page list in page reclaim"), we scan all the tail pages immediately
after a huge page split (see shrink_page_list()). As a result, we can
reclaim up to SWAP_CLUSTER_MAX * HPAGE_PMD_NR (512 MB) in one run!
This is easy to catch on memcg reclaim with zswap enabled. The latter
makes swapout instant so that if we happen to scan an unreferenced huge
page we will evict both its head and tail pages immediately, which is
likely to result in excessive reclaim.
Chris Metcalf [Tue, 8 Sep 2015 22:02:12 +0000 (15:02 -0700)]
bootmem: avoid freeing to bootmem after bootmem is done
Bootmem isn't popular any more, but some architectures still use it, and
freeing to bootmem after calling free_all_bootmem_core() can end up
scribbling over random memory. Instead, make sure the kernel generates
a warning in this case by ensuring the node_bootmem_map field is
non-NULL when are freeing or marking bootmem.
An instance of this bug was just fixed in the tile architecture ("tile:
use free_bootmem_late() for initrd") and catching this case more widely
seems like a good thing.
mem-hotplug: handle node hole when initializing numa_meminfo.
When parsing SRAT, all memory ranges are added into numa_meminfo. In
numa_init(), before entering numa_cleanup_meminfo(), all possible memory
ranges are in numa_meminfo. And numa_cleanup_meminfo() removes all
ranges over max_pfn or empty.
But, this only works if the nodes are continuous. Let's have a look at
the following example:
And numa_cleanup_meminfo() will merge 1 and 2, and remove 8,9 because the
end address is over max_pfn, which is a0800000000. But 4 and 5 are not
removed because their end addresses are less then max_pfn. But in fact,
node 4 and 5 don't exist.
In a word, numa_cleanup_meminfo() is not able to handle holes between nodes.
Since memory ranges in node 4 and 5 are in numa_meminfo, in
numa_register_memblks(), node 4 and 5 will be mistakenly set to online.
If you run lscpu, it will show:
NUMA node0 CPU(s): 0-14,128-142
NUMA node1 CPU(s): 15-29,143-157
NUMA node2 CPU(s):
NUMA node3 CPU(s):
NUMA node4 CPU(s): 62-76,190-204
NUMA node5 CPU(s): 78-92,206-220
In this patch, we use memblock_overlaps_region() to check if ranges in
numa_meminfo overlap with ranges in memory_block. Since memory_block
contains all available memory at boot time, if they overlap, it means the
ranges exist. If not, then remove them from numa_meminfo.
After this patch, lscpu will show:
NUMA node0 CPU(s): 0-14,128-142
NUMA node1 CPU(s): 15-29,143-157
NUMA node4 CPU(s): 62-76,190-204
NUMA node5 CPU(s): 78-92,206-220
Mike Kravetz [Tue, 8 Sep 2015 22:01:54 +0000 (15:01 -0700)]
hugetlbfs: add hugetlbfs_fallocate()
This is based on the shmem version, but it has diverged quite a bit. We
have no swap to worry about, nor the new file sealing. Add
synchronication via the fault mutex table to coordinate page faults,
fallocate allocation and fallocate hole punch.
What this allows us to do is move physical memory in and out of a
hugetlbfs file without having it mapped. This also gives us the ability
to support MADV_REMOVE since it is currently implemented using
fallocate(). MADV_REMOVE lets madvise() remove pages from the middle of
a hugetlbfs file, which wasn't possible before.
hugetlbfs fallocate only operates on whole huge pages.
Mike Kravetz [Tue, 8 Sep 2015 22:01:50 +0000 (15:01 -0700)]
hugetlbfs: New huge_add_to_page_cache helper routine
Currently, there is only a single place where hugetlbfs pages are added
to the page cache. The new fallocate code be adding a second one, so
break the functionality out into its own helper.
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