To help developers and applications gain visibility into writeback
behaviour this patch adds two counters to /proc/vmstat.
# grep nr_dirtied /proc/vmstat
nr_dirtied 3747
# grep nr_written /proc/vmstat
nr_written 3618
These entries allow user apps to understand writeback behaviour over time
and learn how it is impacting their performance. Currently there is no
way to inspect dirty and writeback speed over time. It's not possible for
nr_dirty/nr_writeback.
These entries are necessary to give visibility into writeback behaviour.
We have /proc/diskstats which lets us understand the io in the block
layer. We have blktrace for more in depth understanding. We have
e2fsprogs and debugsfs to give insight into the file systems behaviour,
but we don't offer our users the ability understand what writeback is
doing. There is no way to know how active it is over the whole system, if
it's falling behind or to quantify it's efforts. With these values
exported users can easily see how much data applications are sending
through writeback and also at what rates writeback is processing this
data. Comparing the rates of change between the two allow developers to
see when writeback is not able to keep up with incoming traffic and the
rate of dirty memory being sent to the IO back end. This allows folks to
understand their io workloads and track kernel issues. Non kernel
engineers at Google often use these counters to solve puzzling performance
problems.
Patch #4 adds a pernode vmstat file with nr_dirtied and nr_written
Patch #5 add writeback thresholds to /proc/vmstat
Currently these values are in debugfs. But they should be promoted to
/proc since they are useful for developers who are writing databases
and file servers and are not debugging the kernel.
The output is as below:
# grep threshold /proc/vmstat
nr_pages_dirty_threshold 409111
nr_pages_dirty_background_threshold 818223
This patch:
This allows code outside of the mm core to safely manipulate page
writeback state and not worry about the other accounting. Not using these
routines means that some code will lose track of the accounting and we get
bugs.
Modify nilfs2 to use interface.
Signed-off-by: Michael Rubin <mrubin@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Jiro SEKIBA <jir@unicus.jp>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, sysfs interface of memory hotplug shows whether the section is
removable or not. But it checks only migrateype of pages and doesn't
check details of cluster of pages.
Next, memory hotplug's set_migratetype_isolate() has the same kind of
check, too.
This patch adds the function __count_unmovable_pages() and makes above 2
checks to use the same logic. Then, is_removable and hotremove code uses
the same logic. No changes in the hotremove logic itself.
TODO: need to find a way to check RECLAMABLE. But, considering bit,
calling shrink_slab() against a range before starting memory hotremove
sounds better. If so, this patch's logic doesn't need to be changed.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: Michal Hocko <mhocko@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Non-NUMA systems do never create these files anyway, since they are only
created by driver subsystem when NUMA is configured.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's pointless to kill a task if another thread sharing its mm cannot be
killed to allow future memory freeing. A subsequent patch will prevent
kills in such cases, but first it's necessary to have a way to flag a task
that shares memory with an OOM_DISABLE task that doesn't incur an
additional tasklist scan, which would make select_bad_process() an O(n^2)
function.
This patch adds an atomic counter to struct mm_struct that follows how
many threads attached to it have an oom_score_adj of OOM_SCORE_ADJ_MIN.
They cannot be killed by the kernel, so their memory cannot be freed in
oom conditions.
This only requires task_lock() on the task that we're operating on, it
does not require mm->mmap_sem since task_lock() pins the mm and the
operation is atomic.
[rientjes@google.com: changelog and sys_unshare() code]
[rientjes@google.com: protect oom_disable_count with task_lock in fork]
[rientjes@google.com: use old_mm for oom_disable_count in exec]
Signed-off-by: Ying Han <yinghan@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.infradead.org/battery-2.6:
power_supply: Makefile cleanup
bq27x00_battery: Add missing kfree(di->bus) in bq27x00_battery_remove()
power_supply: Introduce maximum current property
power_supply: Add types for USB chargers
ds2782_battery: Fix units
power_supply: Add driver for TWL4030/TPS65950 BCI charger
bq20z75: Add support for more power supply properties
wm831x_power: Add missing kfree(wm831x_power) in wm831x_power_remove()
jz4740-battery: Add missing kfree(jz_battery) in jz_battery_remove()
ds2760_battery: Add missing kfree(di) in ds2760_battery_remove()
olpc_battery: Fix endian neutral breakage for s16 values
ds2760_battery: Fix W1 and W1_SLAVE_DS2760 dependency
pcf50633-charger: Add missing sysfs_remove_group()
power_supply: Add driver for TI BQ20Z75 gas gauge IC
wm831x_power: Remove duplicate chg mask
omap: rx51: Add support for USB chargers
power_supply: Add isp1704 charger detection driver
* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits)
svcrpc: svc_tcp_sendto XPT_DEAD check is redundant
svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue
svcrpc: assume svc_delete_xprt() called only once
svcrpc: never clear XPT_BUSY on dead xprt
nfsd4: fix connection allocation in sequence()
nfsd4: only require krb5 principal for NFSv4.0 callbacks
nfsd4: move minorversion to client
nfsd4: delay session removal till free_client
nfsd4: separate callback change and callback probe
nfsd4: callback program number is per-session
nfsd4: track backchannel connections
nfsd4: confirm only on succesful create_session
nfsd4: make backchannel sequence number per-session
nfsd4: use client pointer to backchannel session
nfsd4: move callback setup into session init code
nfsd4: don't cache seq_misordered replies
SUNRPC: Properly initialize sock_xprt.srcaddr in all cases
SUNRPC: Use conventional switch statement when reclassifying sockets
sunrpc/xprtrdma: clean up workqueue usage
sunrpc: Turn list_for_each-s into the ..._entry-s
...
Fix up trivial conflicts (two different deprecation notices added in
separate branches) in Documentation/feature-removal-schedule.txt
* 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
net/sunrpc: Use static const char arrays
nfs4: fix channel attribute sanity-checks
NFSv4.1: Use more sensible names for 'initialize_mountpoint'
NFSv4.1: pnfs: filelayout: add driver's LAYOUTGET and GETDEVICEINFO infrastructure
NFSv4.1: pnfs: add LAYOUTGET and GETDEVICEINFO infrastructure
NFS: client needs to maintain list of inodes with active layouts
NFS: create and destroy inode's layout cache
NFSv4.1: pnfs: filelayout: introduce minimal file layout driver
NFSv4.1: pnfs: full mount/umount infrastructure
NFS: set layout driver
NFS: ask for layouttypes during v4 fsinfo call
NFS: change stateid to be a union
NFSv4.1: pnfsd, pnfs: protocol level pnfs constants
SUNRPC: define xdr_decode_opaque_fixed
NFSD: remove duplicate NFS4_STATEID_SIZE
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging: (24 commits)
hwmon: lis3: Release resources in case of failure
hwmon: lis3: Short explanations of platform data fields
hwmon: lis3: Enhance lis3 selftest with IRQ line test
hwmon: lis3: use block read to access data registers
hwmon: lis3: Adjust fuzziness for 8 bit device
hwmon: lis3: New parameters to platform data
hwmon: lis3: restore axis enabled bits
hwmon: lis3: Power on corrections
hwmon: lis3: Update coordinates at polled device open
hwmon: lis3: Cleanup interrupt handling
hwmon: lis3: regulator control
hwmon: lis3: pm_runtime support
Kirkwood: add fan support for Network Space Max v2
hwmon: add generic GPIO fan driver
hwmon: (coretemp) fix reading of microcode revision (v2)
hwmon: ({core, pkg, via-cpu}temp) remove unnecessary CONFIG_HOTPLUG_CPU ifdefs
hwmon: (pkgtemp) align driver initialization style with coretemp
hwmon: LTC4261 Hardware monitoring driver
hwmon: (lis3) add axes module parameter for custom axis-mapping
hwmon: (hp_accel) Add HP Mini 510x family support
...
Add optional blockread function to interface driver. If available
the chip driver uses it for data register access. For 12 bit device
it reads 6 bytes to get 3*16bit data. For 8 bit device it reads out
5 bytes since every second byte is dummy.
This optimizes bus usage and reduces number of operations and
interrupts needed for one data update.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Added default output data rate setting to platform data.
If default rate is 0, reset default value is used.
Added control for duration via platform data.
Added possibility to configure interrupts to trig on
both rising and falling edge. The lis3 WU unit can be
configured quite many ways and with some configurations it
is quite handy to get coordinate refresh when some
event trigs and when it reason goes away.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Based on pm_runtime control, turn lis3 regulators on and off.
Perform context save and restore on transitions.
Feature is optional and must be enabled in platform data.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
This patch adds hwmon support for fans connected to GPIO lines.
Platform specific information such as GPIO pinout and speed conversion array
(rpm from/to GPIO value) are passed to the driver via platform_data.
Signed-off-by: Simon Guinot <sguinot@lacie.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
* 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (67 commits)
SUNRPC: Cleanup duplicate assignment in rpcauth_refreshcred
nfs: fix unchecked value
Ask for time_delta during fsinfo probe
Revalidate caches on lock
SUNRPC: After calling xprt_release(), we must restart from call_reserve
NFSv4: Fix up the 'dircount' hint in encode_readdir
NFSv4: Clean up nfs4_decode_dirent
NFSv4: nfs4_decode_dirent must clear entry->fattr->valid
NFSv4: Fix a regression in decode_getfattr
NFSv4: Fix up decode_attr_filehandle() to handle the case of empty fh pointer
NFS: Ensure we check all allocation return values in new readdir code
NFS: Readdir plus in v4
NFS: introduce generic decode_getattr function
NFS: check xdr_decode for errors
NFS: nfs_readdir_filler catch all errors
NFS: readdir with vmapped pages
NFS: remove page size checking code
NFS: decode_dirent should use an xdr_stream
SUNRPC: Add a helper function xdr_inline_peek
NFS: remove readdir plus limit
...
* 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (163 commits)
omap: complete removal of machine_desc.io_pg_offst and .phys_io
omap: UART: fix wakeup registers for OMAP24xx UART2
omap: Fix spotty MMC voltages
ASoC: OMAP4: MCPDM: Remove unnecessary include of plat/control.h
serial: omap-serial: fix signess error
OMAP3: DMA: Errata i541: sDMA FIFO draining does not finish
omap: dma: Fix buffering disable bit setting for omap24xx
omap: serial: Fix the boot-up crash/reboot without CONFIG_PM
OMAP3: PM: fix scratchpad memory accesses for off-mode
omap4: pandaboard: enable the ehci port on pandaboard
omap4: pandaboard: Fix the init if CONFIG_MMC_OMAP_HS is not set
omap4: pandaboard: remove unused hsmmc definition
OMAP: McBSP: Remove null omap44xx ops comment
OMAP: McBSP: Swap CLKS source definition
OMAP: McBSP: Fix CLKR and FSR signal muxing
OMAP2+: clock: reduce the amount of standard debugging while disabling unused clocks
OMAP: control: move plat-omap/control.h to mach-omap2/control.h
OMAP: split plat-omap/common.c
OMAP: McBSP: implement functional clock switching via clock framework
OMAP: McBSP: implement McBSP CLKR and FSR signal muxing via mach-omap2/mcbsp.c
...
Fixed up trivial conflicts in arch/arm/mach-omap2/
{board-zoom-peripherals.c,devices.c} as per Tony
* 'davinci-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci: (50 commits)
davinci: fix remaining board support after io_pgoffst removal
davinci: mityomapl138: make file local data static
arm/davinci: remove duplicated include
davinci: Initial support for Omapl138-Hawkboard
davinci: MityDSP-L138/MityARM-1808 read MAC address from I2C Prom
davinci: add tnetv107x touchscreen platform device
input: add driver for tnetv107x touchscreen controller
davinci: add keypad config for tnetv107x evm board
davinci: add tnetv107x keypad platform device
input: add driver for tnetv107x on-chip keypad controller
net: davinci_emac: cleanup unused cpdma code
net: davinci_emac: switch to new cpdma layer
net: davinci_emac: separate out cpdma code
net: davinci_emac: cleanup unused mdio emac code
omap: cleanup unused davinci mdio arch code
davinci: cleanup mdio arch code and switch to phy_id
net: davinci_emac: switch to new mdio
omap: add mdio platform devices
davinci: add mdio platform devices
net: davinci_emac: separate out davinci mdio
...
Fix up trivial conflict in drivers/input/keyboard/Kconfig (two entries
added next to each other - one from the davinci merge, one from the
input merge)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (365 commits)
ALSA: hda - Disable sticky PCM stream assignment for AD codecs
ALSA: usb - Creative USB X-Fi volume knob support
ALSA: ca0106: Use card specific dac id for mute controls.
ALSA: ca0106: Allow different sound cards to use different SPI channel mappings.
ALSA: ca0106: Create a nice spot for mapping channels to dacs.
ALSA: ca0106: Move enabling of front dac out of hardcoded setup sequence.
ALSA: ca0106: Pull out dac powering routine into separate function.
ALSA: ca0106 - add Sound Blaster 5.1vx info.
ASoC: tlv320dac33: Use usleep_range for delays
ALSA: usb-audio: add Novation Launchpad support
ALSA: hda - Add workarounds for CT-IBG controllers
ALSA: hda - Fix wrong TLV mute bit for STAC/IDT codecs
ASoC: tpa6130a2: Error handling for broken chip
ASoC: max98088: Staticise m98088_eq_band
ASoC: soc-core: Fix codec->name memory leak
ALSA: hda - Apply ideapad quirk to Acer laptops with Cxt5066
ALSA: hda - Add some workarounds for Creative IBG
ALSA: hda - Fix wrong SPDIF NID assignment for CA0110
ALSA: hda - Fix codec rename rules for ALC662-compatible codecs
ALSA: hda - Add alc_init_jacks() call to other codecs
...
* 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb:
uwb: Orphan the UWB and WUSB subsystems
uwb: Remove the WLP subsystem and drivers
