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2011-11-02memcg: skip scanning active lists based on individual sizeJohannes Weiner
Reclaim decides to skip scanning an active list when the corresponding inactive list is above a certain size in comparison to leave the assumed working set alone while there are still enough reclaim candidates around. The memcg implementation of comparing those lists instead reports whether the whole memcg is low on the requested type of inactive pages, considering all nodes and zones. This can lead to an oversized active list not being scanned because of the state of the other lists in the memcg, as well as an active list being scanned while its corresponding inactive list has enough pages. Not only is this wrong, it's also a scalability hazard, because the global memory state over all nodes and zones has to be gathered for each memcg and zone scanned. Make these calculations purely based on the size of the two LRU lists that are actually affected by the outcome of the decision. Signed-off-by: Johannes Weiner <jweiner@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-02memcg: rename mem variable to memcgRaghavendra K T
The memcg code sometimes uses "struct mem_cgroup *mem" and sometimes uses "struct mem_cgroup *memcg". Rename all mem variables to memcg in source file. Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-02minix: describe usage of different magic numbersSami Kerola
One can get this information from minix/inode.c, but adding the explanations at the definition sites is more appropriate. Signed-off-by: Sami Kerola <kerolasa@iki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-02thp: share get_huge_page_tail()Andrea Arcangeli
This avoids duplicating the function in every arch gup_fast. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-02mm: thp: tail page refcounting fixAndrea Arcangeli
Michel while working on the working set estimation code, noticed that calling get_page_unless_zero() on a random pfn_to_page(random_pfn) wasn't safe, if the pfn ended up being a tail page of a transparent hugepage under splitting by __split_huge_page_refcount(). He then found the problem could also theoretically materialize with page_cache_get_speculative() during the speculative radix tree lookups that uses get_page_unless_zero() in SMP if the radix tree page is freed and reallocated and get_user_pages is called on it before page_cache_get_speculative has a chance to call get_page_unless_zero(). So the best way to fix the problem is to keep page_tail->_count zero at all times. This will guarantee that get_page_unless_zero() can never succeed on any tail page. page_tail->_mapcount is guaranteed zero and is unused for all tail pages of a compound page, so we can simply account the tail page references there and transfer them to tail_page->_count in __split_huge_page_refcount() (in addition to the head_page->_mapcount). While debugging this s/_count/_mapcount/ change I also noticed get_page is called by direct-io.c on pages returned by get_user_pages. That wasn't entirely safe because the two atomic_inc in get_page weren't atomic. As opposed to other get_user_page users like secondary-MMU page fault to establish the shadow pagetables would never call any superflous get_page after get_user_page returns. It's safer to make get_page universally safe for tail pages and to use get_page_foll() within follow_page (inside get_user_pages()). get_page_foll() is safe to do the refcounting for tail pages without taking any locks because it is run within PT lock protected critical sections (PT lock for pte and page_table_lock for pmd_trans_huge). The standard get_page() as invoked by direct-io instead will now take the compound_lock but still only for tail pages. The direct-io paths are usually I/O bound and the compound_lock is per THP so very finegrined, so there's no risk of scalability issues with it. A simple direct-io benchmarks with all lockdep prove locking and spinlock debugging infrastructure enabled shows identical performance and no overhead. So it's worth it. Ideally direct-io should stop calling get_page() on pages returned by get_user_pages(). The spinlock in get_page() is already optimized away for no-THP builds but doing get_page() on tail pages returned by GUP is generally a rare operation and usually only run in I/O paths. This new refcounting on page_tail->_mapcount in addition to avoiding new RCU critical sections will also allow the working set estimation code to work without any further complexity associated to the tail page refcounting with THP. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Michel Lespinasse <walken@google.com> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-01Merge branch 'next/dt' of git://git.linaro.org/people/arnd/arm-socLinus Torvalds
* 'next/dt' of git://git.linaro.org/people/arnd/arm-soc: ARM: gic: use module.h instead of export.h ARM: gic: fix irq_alloc_descs handling for sparse irq ARM: gic: add OF based initialization ARM: gic: add irq_domain support irq: support domains with non-zero hwirq base of/irq: introduce of_irq_init ARM: at91: add at91sam9g20 and Calao USB A9G20 DT support ARM: at91: dt: at91sam9g45 family and board device tree files arm/mx5: add device tree support for imx51 babbage arm/mx5: add device tree support for imx53 boards ARM: msm: Add devicetree support for msm8660-surf msm_serial: Add devicetree support msm_serial: Use relative resources for iomem Fix up conflicts in arch/arm/mach-at91/{at91sam9260.c,at91sam9g45.c}
2011-11-01Merge branch 'next/cleanup2' of git://git.linaro.org/people/arnd/arm-socLinus Torvalds
* 'next/cleanup2' of git://git.linaro.org/people/arnd/arm-soc: (31 commits) ARM: OMAP: Warn if omap_ioremap is called before SoC detection ARM: OMAP: Move set_globals initialization to happen in init_early ARM: OMAP: Map SRAM later on with ioremap_exec() ARM: OMAP: Remove calls to SRAM allocations for framebuffer ARM: OMAP: Avoid cpu_is_omapxxxx usage until map_io is done ARM: OMAP1: Use generic map_io, init_early and init_irq arm/dts: OMAP3+: Add mpu, dsp and iva nodes arm/dts: OMAP4: Add a main ocp entry bound to l3-noc driver ARM: OMAP2+: l3-noc: Add support for device-tree ARM: OMAP2+: board-generic: Add i2c static init ARM: OMAP2+: board-generic: Add DT support to generic board arm/dts: Add support for OMAP3 Beagle board arm/dts: Add initial device tree support for OMAP3 SoC arm/dts: Add support for OMAP4 SDP board arm/dts: Add support for OMAP4 PandaBoard arm/dts: Add initial device tree support for OMAP4 SoC ARM: OMAP: omap_device: Add a method to build an omap_device from a DT node ARM: OMAP: omap_device: Add omap_device_[alloc|delete] for DT integration of: Add helpers to get one string in multiple strings property ARM: OMAP2+: devices: Remove all omap_device_pm_latency structures ... Fix up trivial header file conflicts in arch/arm/mach-omap2/board-generic.c
2011-11-01Merge branch 'next/pm' of git://git.linaro.org/people/arnd/arm-socLinus Torvalds
* 'next/pm' of git://git.linaro.org/people/arnd/arm-soc: (66 commits) ARM: CSR: PM: use outer_resume to resume L2 cache ARM: CSR: call l2x0_of_init to init L2 cache of SiRFprimaII ARM: OMAP: voltage: voltage layer present, even when CONFIG_PM=n ARM: CSR: PM: add sleep entry for SiRFprimaII ARM: CSR: PM: save/restore irq status in suspend cycle ARM: CSR: PM: save/restore timer status in suspend cycle OMAP4: PM: TWL6030: add cmd register OMAP4: PM: TWL6030: fix ON/RET/OFF voltages OMAP4: PM: TWL6030: address 0V conversions OMAP4: PM: TWL6030: fix uv to voltage for >0x39 OMAP4: PM: TWL6030: fix voltage conversion formula omap: voltage: add a stub header file for external/regulator use OMAP2+: VC: more registers are per-channel starting with OMAP5 OMAP3+: voltage: update nominal voltage in voltdm_scale() not VC post-scale OMAP3+: voltage: rename omap_voltage_get_nom_volt -> voltdm_get_voltage OMAP3+: voltdm: final removal of omap_vdd_info OMAP3+: voltage: move/rename curr_volt from vdd_info into struct voltagedomain OMAP3+: voltage: rename scale and reset functions using voltdm_ prefix OMAP3+: VP: combine setting init voltage into common function OMAP3+: VP: remove unused omap_vp_get_curr_volt() ... Fix up trivial conflict in arch/arm/mach-prima2/l2x0.c (code removal vs edit)
2011-11-01Merge branch 'next/timer' of git://git.linaro.org/people/arnd/arm-socLinus Torvalds
* 'next/timer' of git://git.linaro.org/people/arnd/arm-soc: clocksource: fixup ux500 build problems ARM: omap: use __devexit_p in dmtimer driver ARM: ux500: Reprogram timers upon resume ARM: plat-nomadik: timer: Export reset functions ARM: plat-nomadik: timer: Add support for periodic timers ARM: ux500: Move timer code to separate file ARM: ux500: add support for clocksource DBX500 PRCMU clocksource: add DBX500 PRCMU Timer support ARM: plat-nomadik: MTU sched_clock as an option ARM: OMAP: dmtimer: add error handling to export APIs ARM: OMAP: dmtimer: low-power mode support ARM: OMAP: dmtimer: skip reserved timers ARM: OMAP: dmtimer: pm_runtime support ARM: OMAP: dmtimer: switch-over to platform device driver ARM: OMAP: dmtimer: platform driver ARM: OMAP2+: dmtimer: convert to platform devices ARM: OMAP1: dmtimer: conversion to platform devices ARM: OMAP2+: dmtimer: add device names to flck nodes ARM: OMAP: Add support for dmtimer v2 ip
2011-11-01Merge branch 'for-linus/i2c-3.2' of git://git.fluff.org/bjdooks/linuxLinus Torvalds
* 'for-linus/i2c-3.2' of git://git.fluff.org/bjdooks/linux: (47 commits) i2c-s3c2410: Add device tree support i2c-s3c2410: Keep a copy of platform data and use it i2c-nomadik: cosmetic coding style corrections i2c-au1550: dev_pm_ops conversion i2c-au1550: increase timeout waiting for master done i2c-au1550: remove unused ack_timeout i2c-au1550: remove usage of volatile keyword i2c-tegra: __iomem annotation fix i2c-eg20t: Add initialize processing in case i2c-error occurs i2c-eg20t: Fix flag setting issue i2c-eg20t: add stop sequence in case wait-event timeout occurs i2c-eg20t: Separate error processing i2c-eg20t: Fix 10bit access issue i2c-eg20t: Modify returned value s32 to long i2c-eg20t: Fix bus-idle waiting issue i2c-designware: Fix PCI core warning on suspend/resume i2c-designware: Add runtime power management support i2c-designware: Add support for Designware core behind PCI devices. i2c-designware: Push all register reads/writes into the core code. i2c-designware: Support multiple cores using same ISR ...
2011-11-01Merge branch 'for-linus' of git://opensource.wolfsonmicro.com/regulatorLinus Torvalds
* 'for-linus' of git://opensource.wolfsonmicro.com/regulator: (22 commits) regulator: Constify constraints name regulator: Fix possible nullpointer dereference in regulator_enable() regulator: gpio-regulator add dependency on GENERIC_GPIO regulator: Add module.h include to gpio-regulator regulator: Add driver for gpio-controlled regulators regulator: remove duplicate REG_CTRL2 defines in tps65023 regulator: Clarify documentation for regulator-regulator supplies regulator: Fix some bitrot in the machine driver documentation regulator: tps65023: Added support for the similiar TPS65020 chip regulator: tps65023: Setting correct core regulator for tps65021 regulator: tps65023: Set missing bit for update core-voltage regulator: tps65023: Fixes i2c configuration issues regulator: Add debugfs file showing the supply map table regulator: tps6586x: add SMx slew rate setting regulator: tps65023: Fixes i2c configuration issues regulator: tps6507x: Remove num_voltages array regulator: max8952: removed unused mutex. regulator: fix regulator/consumer.h kernel-doc warning regulator: Ensure enough enable time for max8649 regulator: 88pm8607: Fix off-by-one value range checking in the case of no id is matched ...
2011-11-01Merge branch 'pstore' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux * 'pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: pstore: make pstore write function return normal success/fail value pstore: change mutex locking to spin_locks pstore: defer inserting OOPS entries into pstore
2011-11-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (62 commits) mlx4_core: Deprecate log_num_vlan module param IB/mlx4: Don't set VLAN in IBoE WQEs' control segment IB/mlx4: Enable 4K mtu for IBoE RDMA/cxgb4: Mark QP in error before disabling the queue in firmware RDMA/cxgb4: Serialize calls to CQ's comp_handler RDMA/cxgb3: Serialize calls to CQ's comp_handler IB/qib: Fix issue with link states and QSFP cables IB/mlx4: Configure extended active speeds mlx4_core: Add extended port capabilities support IB/qib: Hold links until tuning data is available IB/qib: Clean up checkpatch issue IB/qib: Remove s_lock around header validation IB/qib: Precompute timeout jiffies to optimize latency IB/qib: Use RCU for qpn lookup IB/qib: Eliminate divide/mod in converting idx to egr buf pointer IB/qib: Decode path MTU optimization IB/qib: Optimize RC/UC code by IB operation IPoIB: Use the right function to do DMA unmap pages RDMA/cxgb4: Use correct QID in insert_recv_cqe() RDMA/cxgb4: Make sure flush CQ entries are collected on connection close ...
2011-11-01Merge branches 'amso1100', 'cma', 'cxgb3', 'cxgb4', 'fdr', 'ipath', 'ipoib', ↵Roland Dreier
'misc', 'mlx4', 'misc', 'nes', 'qib' and 'xrc' into for-next
2011-11-01Merge git://github.com/herbertx/cryptoLinus Torvalds
* git://github.com/herbertx/crypto: (48 commits) crypto: user - Depend on NET instead of selecting it crypto: user - Add dependency on NET crypto: talitos - handle descriptor not found in error path crypto: user - Initialise match in crypto_alg_match crypto: testmgr - add twofish tests crypto: testmgr - add blowfish test-vectors crypto: Make hifn_795x build depend on !ARCH_DMA_ADDR_T_64BIT crypto: twofish-x86_64-3way - fix ctr blocksize to 1 crypto: blowfish-x86_64 - fix ctr blocksize to 1 crypto: whirlpool - count rounds from 0 crypto: Add userspace report for compress type algorithms crypto: Add userspace report for cipher type algorithms crypto: Add userspace report for rng type algorithms crypto: Add userspace report for pcompress type algorithms crypto: Add userspace report for nivaead type algorithms crypto: Add userspace report for aead type algorithms crypto: Add userspace report for givcipher type algorithms crypto: Add userspace report for ablkcipher type algorithms crypto: Add userspace report for blkcipher type algorithms crypto: Add userspace report for ahash type algorithms ...
2011-11-01Merge Qualcom Hexagon architectureLinus Torvalds
This is the fifth version of the patchset (with one tiny whitespace fix) to the Linux kernel to support the Qualcomm Hexagon architecture. Between now and the next pull requests, Richard Kuo should have his key signed, etc., and should be back on kernel.org. In the meantime, this got merged as a emailed patch-series. * Hexagon: (36 commits) Add extra arch overrides to asm-generic/checksum.h Hexagon: Add self to MAINTAINERS Hexagon: Add basic stacktrace functionality for Hexagon architecture. Hexagon: Add configuration and makefiles for the Hexagon architecture. Hexagon: Comet platform support Hexagon: kgdb support files Hexagon: Add page-fault support. Hexagon: Add page table header files & etc. Hexagon: Add ioremap support Hexagon: Provide DMA implementation Hexagon: Implement basic TLB management routines for Hexagon. Hexagon: Implement basic cache-flush support Hexagon: Provide basic implementation and/or stubs for I/O routines. Hexagon: Add user access functions Hexagon: Add locking types and functions Hexagon: Add SMP support Hexagon: Provide basic debugging and system trap support. Hexagon: Add ptrace support Hexagon: Add time and timer functions Hexagon: Add interrupts ...
2011-11-01Add extra arch overrides to asm-generic/checksum.hLinas Vepstas
There are plausible reasons for architectures to provide their own versions of csum_partial_copy_nocheck and csum_tcpudp_magic. By protecting these, the architecture can still re-use the asm-generic checksum.h, instead of copying it. Signed-off-by: Linas Vepstas <linas@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-01Hexagon: Add locking types and functionsRichard Kuo
Signed-off-by: Richard Kuo <rkuo@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31Merge branch 'akpm' (Andrew's incoming)Linus Torvalds
Quoth Andrew: - Most of MM. Still waiting for the poweroc guys to get off their butts and review some threaded hugepages patches. - alpha - vfs bits - drivers/misc - a few core kerenl tweaks - printk() features - MAINTAINERS updates - backlight merge - leds merge - various lib/ updates - checkpatch updates * akpm: (127 commits) epoll: fix spurious lockdep warnings checkpatch: add a --strict check for utf-8 in commit logs kernel.h/checkpatch: mark strict_strto<foo> and simple_strto<foo> as obsolete llist-return-whether-list-is-empty-before-adding-in-llist_add-fix wireless: at76c50x: follow rename pack_hex_byte to hex_byte_pack fat: follow rename pack_hex_byte() to hex_byte_pack() security: follow rename pack_hex_byte() to hex_byte_pack() kgdb: follow rename pack_hex_byte() to hex_byte_pack() lib: rename pack_hex_byte() to hex_byte_pack() lib/string.c: fix strim() semantics for strings that have only blanks lib/idr.c: fix comment for ida_get_new_above() lib/percpu_counter.c: enclose hotplug only variables in hotplug ifdef lib/bitmap.c: quiet sparse noise about address space lib/spinlock_debug.c: print owner on spinlock lockup lib/kstrtox: common code between kstrto*() and simple_strto*() functions drivers/leds/leds-lp5521.c: check if reset is successful leds: turn the blink_timer off before starting to blink leds: save the delay values after a successful call to blink_set() drivers/leds/leds-gpio.c: use gpio_get_value_cansleep() when initializing drivers/leds/leds-lm3530.c: add __devexit_p where needed ...
2011-10-31kernel.h/checkpatch: mark strict_strto<foo> and simple_strto<foo> as obsoleteJoe Perches
Mark obsolete/deprecated strict_strto<foo> and simple_strto<foo> functions and macros as obsolete. Update checkpatch to warn about their use. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31llist-return-whether-list-is-empty-before-adding-in-llist_add-fixAndrew Morton
clarify comment Cc: Huang Ying <ying.huang@intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.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>
2011-10-31lib: rename pack_hex_byte() to hex_byte_pack()Andy Shevchenko
As suggested by Andrew Morton in [1] there is better to have most significant part first in the function name. [1] https://lkml.org/lkml/2011/9/20/22 There is no functional change. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Mimi Zohar <zohar@us.ibm.com> Cc: James Morris <jmorris@namei.org> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: "John W. Linville" <linville@tuxdriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31drivers/leds/leds-renesas-tpu.c: move Renesas TPU LED driver platform dataMagnus Damm
Use the platform_data include directory for the TPU LED driver, as suggested by Paul Mundt. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31leds: Renesas TPU LED driverMagnus Damm
Add V2 of the LED driver for a single timer channel for the TPU hardware block commonly found in Renesas SoCs. The driver has been written with optimal Power Management in mind, so to save power the LED is driven as a regular GPIO pin in case of maximum brightness and power off which allows the TPU hardware to be idle and which in turn allows the clocks to be stopped and the power domain to be turned off transparently. Any other brightness level requires use of the TPU hardware in PWM mode. TPU hardware device clocks and power are managed through Runtime PM. System suspend and resume is known to be working - during suspend the LED is set to off by the generic LED code. The TPU hardware timer is equipeed with a 16-bit counter together with an up-to-divide-by-64 prescaler which makes the hardware suitable for brightness control. Hardware blink is unsupported. The LED PWM waveform has been verified with a Fluke 123 Scope meter on a sh7372 Mackerel board. Tested with experimental sh7372 A3SP power domain patches. Platform device bind/unbind tested ok. V2 has been tested on the DS2 LED of the sh73a0-based AG5EVM. [axel.lin@gmail.com: include linux/module.h] Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31backlight: fix broken regulator API usage in l4f00242t03Mark Brown
The regulator support in the l4f00242t03 is very non-idiomatic. Rather than requesting the regulators based on the device name and the supply names used by the device the driver requires boards to pass system specific supply names around through platform data. The driver also conditionally requests the regulators based on this platform data, adding unneeded conditional code to the driver. Fix this by removing the platform data and converting to the standard idiom, also updating all in tree users of the driver. As no datasheet appears to be available for the LCD I'm guessing the names for the supplies based on the existing users and I've no ability to do anything more than compile test. The use of regulator_set_voltage() in the driver is also problematic, since fixed voltages are required the expectation would be that the voltages would be fixed in the constraints set by the machines rather than manually configured by the driver, but is less problematic. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31treewide: use __printf not __attribute__((format(printf,...)))Joe Perches
Standardize the style for compiler based printf format verification. Standardized the location of __printf too. Done via script and a little typing. $ grep -rPl --include=*.[ch] -w "__attribute__" * | \ grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \ xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*\)\s*\)\s*\)/__printf($1, $2)/g ; print; }' [akpm@linux-foundation.org: revert arch bits] Signed-off-by: Joe Perches <joe@perches.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31lis3lv02d: make regulator API usage unconditionalMark Brown
The regulator API contains a range of features for stubbing itself out when not in use and for transparently restricting the actual effect of regulator API calls where they can't be supported on a particular system so that drivers don't need to individually implement this. Simplify the driver slightly by making use of this idiom. The only in tree user is ecovec24 which does not use the regulator API. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Éric Piel <eric.piel@tremplin-utc.net> Cc: Ilkka Koskinen <ilkka.koskinen@nokia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: compaction: make compact_zone_order() staticKyungmin Park
There's no compact_zone_order() user outside file scope, so make it static. Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31vmscan: fix shrinker callback bug in fs/super.cMikulas Patocka
The callback must not return -1 when nr_to_scan is zero. Fix the bug in fs/super.c and add this requirement to the callback specification. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: neaten warn_alloc_failedJoe Perches
Add __attribute__((format (printf...) to the function to validate format and arguments. Use vsprintf extension %pV to avoid any possible message interleaving. Coalesce format string. Convert printks/pr_warning to pr_warn. [akpm@linux-foundation.org: use the __printf() macro] Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31include/asm-generic/page.h: calculate virt_to_page and page_to_virt via ↵Sonic Zhang
predefined macro On NOMMU architectures, if physical memory doesn't start from 0, ARCH_PFN_OFFSET is defined to generate page index in mem_map array. Because virtual address is equal to physical address, PAGE_OFFSET is always 0. virt_to_page and page_to_virt should not index page by PAGE_OFFSET directly. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31thp: mremap support and TLB optimizationAndrea Arcangeli
This adds THP support to mremap (decreases the number of split_huge_page() calls). Here are also some benchmarks with a proggy like this: === #define _GNU_SOURCE #include <sys/mman.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <sys/time.h> #define SIZE (5UL*1024*1024*1024) int main() { static struct timeval oldstamp, newstamp; long diffsec; char *p, *p2, *p3, *p4; if (posix_memalign((void **)&p, 2*1024*1024, SIZE)) perror("memalign"), exit(1); if (posix_memalign((void **)&p2, 2*1024*1024, SIZE)) perror("memalign"), exit(1); if (posix_memalign((void **)&p3, 2*1024*1024, 4096)) perror("memalign"), exit(1); memset(p, 0xff, SIZE); memset(p2, 0xff, SIZE); memset(p3, 0x77, 4096); gettimeofday(&oldstamp, NULL); p4 = mremap(p, SIZE, SIZE, MREMAP_FIXED|MREMAP_MAYMOVE, p3); gettimeofday(&newstamp, NULL); diffsec = newstamp.tv_sec - oldstamp.tv_sec; diffsec = newstamp.tv_usec - oldstamp.tv_usec + 1000000 * diffsec; printf("usec %ld\n", diffsec); if (p == MAP_FAILED || p4 != p3) //if (p == MAP_FAILED) perror("mremap"), exit(1); if (memcmp(p4, p2, SIZE)) printf("mremap bug\n"), exit(1); printf("ok\n"); return 0; } === THP on Performance counter stats for './largepage13' (3 runs): 69195836 dTLB-loads ( +- 3.546% ) (scaled from 50.30%) 60708 dTLB-load-misses ( +- 11.776% ) (scaled from 52.62%) 676266476 dTLB-stores ( +- 5.654% ) (scaled from 69.54%) 29856 dTLB-store-misses ( +- 4.081% ) (scaled from 89.22%) 1055848782 iTLB-loads ( +- 4.526% ) (scaled from 80.18%) 8689 iTLB-load-misses ( +- 2.987% ) (scaled from 58.20%) 7.314454164 seconds time elapsed ( +- 0.023% ) THP off Performance counter stats for './largepage13' (3 runs): 1967379311 dTLB-loads ( +- 0.506% ) (scaled from 60.59%) 9238687 dTLB-load-misses ( +- 22.547% ) (scaled from 61.87%) 2014239444 dTLB-stores ( +- 0.692% ) (scaled from 60.40%) 3312335 dTLB-store-misses ( +- 7.304% ) (scaled from 67.60%) 6764372065 iTLB-loads ( +- 0.925% ) (scaled from 79.00%) 8202 iTLB-load-misses ( +- 0.475% ) (scaled from 70.55%) 9.693655243 seconds time elapsed ( +- 0.069% ) grep thp /proc/vmstat thp_fault_alloc 35849 thp_fault_fallback 0 thp_collapse_alloc 3 thp_collapse_alloc_failed 0 thp_split 0 thp_split 0 confirms no thp split despite plenty of hugepages allocated. The measurement of only the mremap time (so excluding the 3 long memset and final long 10GB memory accessing memcmp): THP on usec 14824 usec 14862 usec 14859 THP off usec 256416 usec 255981 usec 255847 With an older kernel without the mremap optimizations (the below patch optimizes the non THP version too). THP on usec 392107 usec 390237 usec 404124 THP off usec 444294 usec 445237 usec 445820 I guess with a threaded program that sends more IPI on large SMP it'd create an even larger difference. All debug options are off except DEBUG_VM to avoid skewing the results. The only problem for native 2M mremap like it happens above both the source and destination address must be 2M aligned or the hugepmd can't be moved without a split but that is an hardware limitation. [akpm@linux-foundation.org: coding-style nitpicking] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <jweiner@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31memblock: add memblock_start_of_DRAM()Sam Ravnborg
SPARC32 require access to the start address. Add a new helper memblock_start_of_DRAM() to give access to the address of the first memblock - which contains the lowest address. The awkward name was chosen to match the already present memblock_end_of_DRAM(). Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: avoid null pointer access in vm_struct via /proc/vmallocinfoMitsuo Hayasaka
The /proc/vmallocinfo shows information about vmalloc allocations in vmlist that is a linklist of vm_struct. It, however, may access pages field of vm_struct where a page was not allocated. This results in a null pointer access and leads to a kernel panic. Why this happens: In __vmalloc_node_range() called from vmalloc(), newly allocated vm_struct is added to vmlist at __get_vm_area_node() and then, some fields of vm_struct such as nr_pages and pages are set at __vmalloc_area_node(). In other words, it is added to vmlist before it is fully initialized. At the same time, when the /proc/vmallocinfo is read, it accesses the pages field of vm_struct according to the nr_pages field at show_numa_info(). Thus, a null pointer access happens. The patch adds the newly allocated vm_struct to the vmlist *after* it is fully initialized. So, it can avoid accessing the pages field with unallocated page when show_numa_info() is called. Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31lib/string.c: introduce memchr_inv()Akinobu Mita
memchr_inv() is mainly used to check whether the whole buffer is filled with just a specified byte. The function name and prototype are stolen from logfs and the implementation is from SLUB. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Acked-by: Joern Engel <joern@logfs.org> Cc: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: vmscan: immediately reclaim end-of-LRU dirty pages when writeback completesMel Gorman
When direct reclaim encounters a dirty page, it gets recycled around the LRU for another cycle. This patch marks the page PageReclaim similar to deactivate_page() so that the page gets reclaimed almost immediately after the page gets cleaned. This is to avoid reclaiming clean pages that are younger than a dirty page encountered at the end of the LRU that might have been something like a use-once page. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <jweiner@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Alex Elder <aelder@sgi.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: vmscan: do not writeback filesystem pages in direct reclaimMel Gorman
Testing from the XFS folk revealed that there is still too much I/O from the end of the LRU in kswapd. Previously it was considered acceptable by VM people for a small number of pages to be written back from reclaim with testing generally showing about 0.3% of pages reclaimed were written back (higher if memory was low). That writing back a small number of pages is ok has been heavily disputed for quite some time and Dave Chinner explained it well; It doesn't have to be a very high number to be a problem. IO is orders of magnitude slower than the CPU time it takes to flush a page, so the cost of making a bad flush decision is very high. And single page writeback from the LRU is almost always a bad flush decision. To complicate matters, filesystems respond very differently to requests from reclaim according to Christoph Hellwig; xfs tries to write it back if the requester is kswapd ext4 ignores the request if it's a delayed allocation btrfs ignores the request As a result, each filesystem has different performance characteristics when under memory pressure and there are many pages being dirtied. In some cases, the request is ignored entirely so the VM cannot depend on the IO being dispatched. The objective of this series is to reduce writing of filesystem-backed pages from reclaim, play nicely with writeback that is already in progress and throttle reclaim appropriately when writeback pages are encountered. The assumption is that the flushers will always write pages faster than if reclaim issues the IO. A secondary goal is to avoid the problem whereby direct reclaim splices two potentially deep call stacks together. There is a potential new problem as reclaim has less control over how long before a page in a particularly zone or container is cleaned and direct reclaimers depend on kswapd or flusher threads to do the necessary work. However, as filesystems sometimes ignore direct reclaim requests already, it is not expected to be a serious issue. Patch 1 disables writeback of filesystem pages from direct reclaim entirely. Anonymous pages are still written. Patch 2 removes dead code in lumpy reclaim as it is no longer able to synchronously write pages. This hurts lumpy reclaim but there is an expectation that compaction is used for hugepage allocations these days and lumpy reclaim's days are numbered. Patches 3-4 add warnings to XFS and ext4 if called from direct reclaim. With patch 1, this "never happens" and is intended to catch regressions in this logic in the future. Patch 5 disables writeback of filesystem pages from kswapd unless the priority is raised to the point where kswapd is considered to be in trouble. Patch 6 throttles reclaimers if too many dirty pages are being encountered and the zones or backing devices are congested. Patch 7 invalidates dirty pages found at the end of the LRU so they are reclaimed quickly after being written back rather than waiting for a reclaimer to find them I consider this series to be orthogonal to the writeback work but it is worth noting that the writeback work affects the viability of patch 8 in particular. I tested this on ext4 and xfs using fs_mark, a simple writeback test based on dd and a micro benchmark that does a streaming write to a large mapping (exercises use-once LRU logic) followed by streaming writes to a mix of anonymous and file-backed mappings. The command line for fs_mark when botted with 512M looked something like ./fs_mark -d /tmp/fsmark-2676 -D 100 -N 150 -n 150 -L 25 -t 1 -S0 -s 10485760 The number of files was adjusted depending on the amount of available memory so that the files created was about 3xRAM. For multiple threads, the -d switch is specified multiple times. The test machine is x86-64 with an older generation of AMD processor with 4 cores. The underlying storage was 4 disks configured as RAID-0 as this was the best configuration of storage I had available. Swap is on a separate disk. Dirty ratio was tuned to 40% instead of the default of 20%. Testing was run with and without monitors to both verify that the patches were operating as expected and that any performance gain was real and not due to interference from monitors. Here is a summary of results based on testing XFS. 512M1P-xfs Files/s mean 32.69 ( 0.00%) 34.44 ( 5.08%) 512M1P-xfs Elapsed Time fsmark 51.41 48.29 512M1P-xfs Elapsed Time simple-wb 114.09 108.61 512M1P-xfs Elapsed Time mmap-strm 113.46 109.34 512M1P-xfs Kswapd efficiency fsmark 62% 63% 512M1P-xfs Kswapd efficiency simple-wb 56% 61% 512M1P-xfs Kswapd efficiency mmap-strm 44% 42% 512M-xfs Files/s mean 30.78 ( 0.00%) 35.94 (14.36%) 512M-xfs Elapsed Time fsmark 56.08 48.90 512M-xfs Elapsed Time simple-wb 112.22 98.13 512M-xfs Elapsed Time mmap-strm 219.15 196.67 512M-xfs Kswapd efficiency fsmark 54% 56% 512M-xfs Kswapd efficiency simple-wb 54% 55% 512M-xfs Kswapd efficiency mmap-strm 45% 44% 512M-4X-xfs Files/s mean 30.31 ( 0.00%) 33.33 ( 9.06%) 512M-4X-xfs Elapsed Time fsmark 63.26 55.88 512M-4X-xfs Elapsed Time simple-wb 100.90 90.25 512M-4X-xfs Elapsed Time mmap-strm 261.73 255.38 512M-4X-xfs Kswapd efficiency fsmark 49% 50% 512M-4X-xfs Kswapd efficiency simple-wb 54% 56% 512M-4X-xfs Kswapd efficiency mmap-strm 37% 36% 512M-16X-xfs Files/s mean 60.89 ( 0.00%) 65.22 ( 6.64%) 512M-16X-xfs Elapsed Time fsmark 67.47 58.25 512M-16X-xfs Elapsed Time simple-wb 103.22 90.89 512M-16X-xfs Elapsed Time mmap-strm 237.09 198.82 512M-16X-xfs Kswapd efficiency fsmark 45% 46% 512M-16X-xfs Kswapd efficiency simple-wb 53% 55% 512M-16X-xfs Kswapd efficiency mmap-strm 33% 33% Up until 512-4X, the FSmark improvements were statistically significant. For the 4X and 16X tests the results were within standard deviations but just barely. The time to completion for all tests is improved which is an important result. In general, kswapd efficiency is not affected by skipping dirty pages. 1024M1P-xfs Files/s mean 39.09 ( 0.00%) 41.15 ( 5.01%) 1024M1P-xfs Elapsed Time fsmark 84.14 80.41 1024M1P-xfs Elapsed Time simple-wb 210.77 184.78 1024M1P-xfs Elapsed Time mmap-strm 162.00 160.34 1024M1P-xfs Kswapd efficiency fsmark 69% 75% 1024M1P-xfs Kswapd efficiency simple-wb 71% 77% 1024M1P-xfs Kswapd efficiency mmap-strm 43% 44% 1024M-xfs Files/s mean 35.45 ( 0.00%) 37.00 ( 4.19%) 1024M-xfs Elapsed Time fsmark 94.59 91.00 1024M-xfs Elapsed Time simple-wb 229.84 195.08 1024M-xfs Elapsed Time mmap-strm 405.38 440.29 1024M-xfs Kswapd efficiency fsmark 79% 71% 1024M-xfs Kswapd efficiency simple-wb 74% 74% 1024M-xfs Kswapd efficiency mmap-strm 39% 42% 1024M-4X-xfs Files/s mean 32.63 ( 0.00%) 35.05 ( 6.90%) 1024M-4X-xfs Elapsed Time fsmark 103.33 97.74 1024M-4X-xfs Elapsed Time simple-wb 204.48 178.57 1024M-4X-xfs Elapsed Time mmap-strm 528.38 511.88 1024M-4X-xfs Kswapd efficiency fsmark 81% 70% 1024M-4X-xfs Kswapd efficiency simple-wb 73% 72% 1024M-4X-xfs Kswapd efficiency mmap-strm 39% 38% 1024M-16X-xfs Files/s mean 42.65 ( 0.00%) 42.97 ( 0.74%) 1024M-16X-xfs Elapsed Time fsmark 103.11 99.11 1024M-16X-xfs Elapsed Time simple-wb 200.83 178.24 1024M-16X-xfs Elapsed Time mmap-strm 397.35 459.82 1024M-16X-xfs Kswapd efficiency fsmark 84% 69% 1024M-16X-xfs Kswapd efficiency simple-wb 74% 73% 1024M-16X-xfs Kswapd efficiency mmap-strm 39% 40% All FSMark tests up to 16X had statistically significant improvements. For the most part, tests are completing faster with the exception of the streaming writes to a mixture of anonymous and file-backed mappings which were slower in two cases In the cases where the mmap-strm tests were slower, there was more swapping due to dirty pages being skipped. The number of additional pages swapped is almost identical to the fewer number of pages written from reclaim. In other words, roughly the same number of pages were reclaimed but swapping was slower. As the test is a bit unrealistic and stresses memory heavily, the small shift is acceptable. 4608M1P-xfs Files/s mean 29.75 ( 0.00%) 30.96 ( 3.91%) 4608M1P-xfs Elapsed Time fsmark 512.01 492.15 4608M1P-xfs Elapsed Time simple-wb 618.18 566.24 4608M1P-xfs Elapsed Time mmap-strm 488.05 465.07 4608M1P-xfs Kswapd efficiency fsmark 93% 86% 4608M1P-xfs Kswapd efficiency simple-wb 88% 84% 4608M1P-xfs Kswapd efficiency mmap-strm 46% 45% 4608M-xfs Files/s mean 27.60 ( 0.00%) 28.85 ( 4.33%) 4608M-xfs Elapsed Time fsmark 555.96 532.34 4608M-xfs Elapsed Time simple-wb 659.72 571.85 4608M-xfs Elapsed Time mmap-strm 1082.57 1146.38 4608M-xfs Kswapd efficiency fsmark 89% 91% 4608M-xfs Kswapd efficiency simple-wb 88% 82% 4608M-xfs Kswapd efficiency mmap-strm 48% 46% 4608M-4X-xfs Files/s mean 26.00 ( 0.00%) 27.47 ( 5.35%) 4608M-4X-xfs Elapsed Time fsmark 592.91 564.00 4608M-4X-xfs Elapsed Time simple-wb 616.65 575.07 4608M-4X-xfs Elapsed Time mmap-strm 1773.02 1631.53 4608M-4X-xfs Kswapd efficiency fsmark 90% 94% 4608M-4X-xfs Kswapd efficiency simple-wb 87% 82% 4608M-4X-xfs Kswapd efficiency mmap-strm 43% 43% 4608M-16X-xfs Files/s mean 26.07 ( 0.00%) 26.42 ( 1.32%) 4608M-16X-xfs Elapsed Time fsmark 602.69 585.78 4608M-16X-xfs Elapsed Time simple-wb 606.60 573.81 4608M-16X-xfs Elapsed Time mmap-strm 1549.75 1441.86 4608M-16X-xfs Kswapd efficiency fsmark 98% 98% 4608M-16X-xfs Kswapd efficiency simple-wb 88% 82% 4608M-16X-xfs Kswapd efficiency mmap-strm 44% 42% Unlike the other tests, the fsmark results are not statistically significant but the min and max times are both improved and for the most part, tests completed faster. There are other indications that this is an improvement as well. For example, in the vast majority of cases, there were fewer pages scanned by direct reclaim implying in many cases that stalls due to direct reclaim are reduced. KSwapd is scanning more due to skipping dirty pages which is unfortunate but the CPU usage is still acceptable In an earlier set of tests, I used blktrace and in almost all cases throughput throughout the entire test was higher. However, I ended up discarding those results as recording blktrace data was too heavy for my liking. On a laptop, I plugged in a USB stick and ran a similar tests of tests using it as backing storage. A desktop environment was running and for the entire duration of the tests, firefox and gnome terminal were launching and exiting to vaguely simulate a user. 1024M-xfs Files/s mean 0.41 ( 0.00%) 0.44 ( 6.82%) 1024M-xfs Elapsed Time fsmark 2053.52 1641.03 1024M-xfs Elapsed Time simple-wb 1229.53 768.05 1024M-xfs Elapsed Time mmap-strm 4126.44 4597.03 1024M-xfs Kswapd efficiency fsmark 84% 85% 1024M-xfs Kswapd efficiency simple-wb 92% 81% 1024M-xfs Kswapd efficiency mmap-strm 60% 51% 1024M-xfs Avg wait ms fsmark 5404.53 4473.87 1024M-xfs Avg wait ms simple-wb 2541.35 1453.54 1024M-xfs Avg wait ms mmap-strm 3400.25 3852.53 The mmap-strm results were hurt because firefox launching had a tendency to push the test out of memory. On the postive side, firefox launched marginally faster with the patches applied. Time to completion for many tests was faster but more importantly - the "Avg wait" time as measured by iostat was far lower implying the system would be more responsive. It was also the case that "Avg wait ms" on the root filesystem was lower. I tested it manually and while the system felt slightly more responsive while copying data to a USB stick, it was marginal enough that it could be my imagination. This patch: do not writeback filesystem pages in direct reclaim. When kswapd is failing to keep zones above the min watermark, a process will enter direct reclaim in the same manner kswapd does. If a dirty page is encountered during the scan, this page is written to backing storage using mapping->writepage. This causes two problems. First, it can result in very deep call stacks, particularly if the target storage or filesystem are complex. Some filesystems ignore write requests from direct reclaim as a result. The second is that a single-page flush is inefficient in terms of IO. While there is an expectation that the elevator will merge requests, this does not always happen. Quoting Christoph Hellwig; The elevator has a relatively small window it can operate on, and can never fix up a bad large scale writeback pattern. This patch prevents direct reclaim writing back filesystem pages by checking if current is kswapd. Anonymous pages are still written to swap as there is not the equivalent of a flusher thread for anonymous pages. If the dirty pages cannot be written back, they are placed back on the LRU lists. There is now a direct dependency on dirty page balancing to prevent too many pages in the system being dirtied which would prevent reclaim making forward progress. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Alex Elder <aelder@sgi.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: add comments to explain mm_struct fieldsChristoph Lameter
Add comments to explain the page statistics field in the mm_struct. [akpm@linux-foundation.org: add missing ;] Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: distinguish between mlocked and pinned pagesChristoph Lameter
Some kernel components pin user space memory (infiniband and perf) (by increasing the page count) and account that memory as "mlocked". The difference between mlocking and pinning is: A. mlocked pages are marked with PG_mlocked and are exempt from swapping. Page migration may move them around though. They are kept on a special LRU list. B. Pinned pages cannot be moved because something needs to directly access physical memory. They may not be on any LRU list. I recently saw an mlockalled process where mm->locked_vm became bigger than the virtual size of the process (!) because some memory was accounted for twice: Once when the page was mlocked and once when the Infiniband layer increased the refcount because it needt to pin the RDMA memory. This patch introduces a separate counter for pinned pages and accounts them seperately. Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Mike Marciniszyn <infinipath@qlogic.com> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31oom: fix race while temporarily setting current's oom_score_adjDavid Rientjes
test_set_oom_score_adj() was introduced in 72788c385604 ("oom: replace PF_OOM_ORIGIN with toggling oom_score_adj") to temporarily elevate current's oom_score_adj for ksm and swapoff without requiring an additional per-process flag. Using that function to both set oom_score_adj to OOM_SCORE_ADJ_MAX and then reinstate the previous value is racy since it's possible that userspace can set the value to something else itself before the old value is reinstated. That results in userspace setting current's oom_score_adj to a different value and then the kernel immediately setting it back to its previous value without notification. To fix this, a new compare_swap_oom_score_adj() function is introduced with the same semantics as the compare and swap CAS instruction, or CMPXCHG on x86. It is used to reinstate the previous value of oom_score_adj if and only if the present value is the same as the old value. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ying Han <yinghan@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31oom: remove oom_disable_countDavid Rientjes
This removes mm->oom_disable_count entirely since it's unnecessary and currently buggy. The counter was intended to be per-process but it's currently decremented in the exit path for each thread that exits, causing it to underflow. The count was originally intended to prevent oom killing threads that share memory with threads that cannot be killed since it doesn't lead to future memory freeing. The counter could be fixed to represent all threads sharing the same mm, but it's better to remove the count since: - it is possible that the OOM_DISABLE thread sharing memory with the victim is waiting on that thread to exit and will actually cause future memory freeing, and - there is no guarantee that a thread is disabled from oom killing just because another thread sharing its mm is oom disabled. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Ying Han <yinghan@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: zone_reclaim: make isolate_lru_page() filter-awareMinchan Kim
In __zone_reclaim case, we don't want to shrink mapped page. Nonetheless, we have isolated mapped page and re-add it into LRU's head. It's unnecessary CPU overhead and makes LRU churning. Of course, when we isolate the page, the page might be mapped but when we try to migrate the page, the page would be not mapped. So it could be migrated. But race is rare and although it happens, it's no big deal. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: compaction: make isolate_lru_page() filter-awareMinchan Kim
In async mode, compaction doesn't migrate dirty or writeback pages. So, it's meaningless to pick the page and re-add it to lru list. Of course, when we isolate the page in compaction, the page might be dirty or writeback but when we try to migrate the page, the page would be not dirty, writeback. So it could be migrated. But it's very unlikely as isolate and migration cycle is much faster than writeout. So, this patch helps cpu overhead and prevent unnecessary LRU churning. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: change isolate mode from #define to bitwise typeMinchan Kim
Change ISOLATE_XXX macro with bitwise isolate_mode_t type. Normally, macro isn't recommended as it's type-unsafe and making debugging harder as symbol cannot be passed throught to the debugger. Quote from Johannes " Hmm, it would probably be cleaner to fully convert the isolation mode into independent flags. INACTIVE, ACTIVE, BOTH is currently a tri-state among flags, which is a bit ugly." This patch moves isolate mode from swap.h to mmzone.h by memcontrol.h Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31Cross Memory AttachChristopher Yeoh
The basic idea behind cross memory attach is to allow MPI programs doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. The following patch attempts to achieve this by allowing a destination process, given an address and size from a source process, to copy memory directly from the source process into its own address space via a system call. There is also a symmetrical ability to copy from the current process's address space into a destination process's address space. - Use of /proc/pid/mem has been considered, but there are issues with using it: - Does not allow for specifying iovecs for both src and dest, assuming preadv or pwritev was implemented either the area read from or written to would need to be contiguous. - Currently mem_read allows only processes who are currently ptrace'ing the target and are still able to ptrace the target to read from the target. This check could possibly be moved to the open call, but its not clear exactly what race this restriction is stopping (reason appears to have been lost) - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix domain socket is a bit ugly from a userspace point of view, especially when you may have hundreds if not (eventually) thousands of processes that all need to do this with each other - Doesn't allow for some future use of the interface we would like to consider adding in the future (see below) - Interestingly reading from /proc/pid/mem currently actually involves two copies! (But this could be fixed pretty easily) As mentioned previously use of vmsplice instead was considered, but has problems. Since you need the reader and writer working co-operatively if the pipe is not drained then you block. Which requires some wrapping to do non blocking on the send side or polling on the receive. In all to all communication it requires ordering otherwise you can deadlock. And in the example of many MPI tasks writing to one MPI task vmsplice serialises the copying. There are some cases of MPI collectives where even a single copy interface does not get us the performance gain we could. For example in an MPI_Reduce rather than copy the data from the source we would like to instead use it directly in a mathops (say the reduce is doing a sum) as this would save us doing a copy. We don't need to keep a copy of the data from the source. I haven't implemented this, but I think this interface could in the future do all this through the use of the flags - eg could specify the math operation and type and the kernel rather than just copying the data would apply the specified operation between the source and destination and store it in the destination. Although we don't have a "second user" of the interface (though I've had some nibbles from people who may be interested in using it for intra process messaging which is not MPI). This interface is something which hardware vendors are already doing for their custom drivers to implement fast local communication. And so in addition to this being useful for OpenMPI it would mean the driver maintainers don't have to fix things up when the mm changes. There was some discussion about how much faster a true zero copy would go. Here's a link back to the email with some testing I did on that: http://marc.info/?l=linux-mm&m=130105930902915&w=2 There is a basic man page for the proposed interface here: http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt This has been implemented for x86 and powerpc, other architecture should mainly (I think) just need to add syscall numbers for the process_vm_readv and process_vm_writev. There are 32 bit compatibility versions for 64-bit kernels. For arch maintainers there are some simple tests to be able to quickly verify that the syscalls are working correctly here: http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgz Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <linux-man@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31include/linux/dmar.h: forward-declare struct acpi_dmar_headerAndrew Morton
x86_64 allnoconfig: In file included from arch/x86/kernel/pci-dma.c:3: include/linux/dmar.h:248: warning: 'struct acpi_dmar_header' declared inside parameter list include/linux/dmar.h:248: warning: its scope is only this definition or declaration, which is probably not what you want Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31dma-mapping: fix sync_single_range_* DMA debuggingClemens Ladisch
Commit 5fd75a7850b5 (dma-mapping: remove unnecessary sync_single_range_* in dma_map_ops) unified not only the dma_map_ops but also the corresponding debug_dma_sync_* calls. This led to spurious WARN()ings like the following because the DMA debug code was no longer able to detect the DMA buffer base address without the separate offset parameter: WARNING: at lib/dma-debug.c:911 check_sync+0xce/0x446() firewire_ohci 0000:04:00.0: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x00000000cedaa400] [size=1024 bytes] Call Trace: ... [<ffffffff811326a5>] check_sync+0xce/0x446 [<ffffffff81132ad9>] debug_dma_sync_single_for_device+0x39/0x3b [<ffffffffa01d6e6a>] ohci_queue_iso+0x4f3/0x77d [firewire_ohci] ... To fix this, unshare the sync_single_* and sync_single_range_* implementations so that we are able to call the correct debug_dma_sync_* functions. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (54 commits) [S390] Remove error checking from copy_oldmem_page() [S390] qdio: prevent dsci access without adapter interrupts [S390] irqstats: split IPI interrupt accounting [S390] add missing __tlb_flush_global() for !CONFIG_SMP [S390] sparse: fix sparse symbol shadow warning [S390] sparse: fix sparse NULL pointer warnings [S390] sparse: fix sparse warnings with __user pointers [S390] sparse: fix sparse warnings in math-emu [S390] sparse: fix sparse warnings about missing prototypes [S390] sparse: fix sparse ANSI-C warnings [S390] sparse: fix sparse static warnings [S390] sparse: fix access past end of array warnings [S390] dasd: prevent path verification before resume [S390] qdio: remove multicast polling [S390] qdio: reset outbound SBAL error states [S390] qdio: EQBS retry after CCQ 96 [S390] qdio: add timestamp for last queue scan time [S390] Introduce get_clock_fast() [S390] kvm: Handle diagnose 0x10 (release pages) [S390] take mmap_sem when walking guest page table ...
2011-10-31Merge branch 'v4l_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (348 commits) [media] pctv452e: Remove bogus code [media] adv7175: Make use of media bus pixel codes [media] media: vb2: fix incorrect return value [media] em28xx: implement VIDIOC_ENUM_FRAMESIZES [media] cx23885: Stop the risc video fifo before reconfiguring it [media] cx23885: Avoid incorrect error handling and reporting [media] cx23885: Avoid stopping the risc engine during buffer timeout [media] cx23885: Removed a spurious function cx23885_set_scale() [media] cx23885: v4l2 api compliance, set the audioset field correctly [media] cx23885: hook the audio selection functions into the main driver [media] cx23885: add generic functions for dealing with audio input selection [media] cx23885: fixes related to maximum number of inputs and range checking [media] cx23885: Initial support for the MPX-885 mini-card [media] cx25840: Ensure AUDIO6 and AUDIO7 trigger line-in baseband use [media] cx23885: Enable audio line in support from the back panel [media] cx23885: Allow the audio mux config to be specified on a per input basis [media] cx25840: Enable support for non-tuner LR1/LR2 audio inputs [media] cx23885: Name an internal i2c part and declare a bitfield by name [media] cx23885: Ensure VBI buffers timeout quickly - bugfix for vbi hangs during streaming [media] cx23885: remove channel dump diagnostics when a vbi buffer times out ... Fix up trivial conflicts in drivers/misc/altera-stapl/altera.c (header file rename vs add)
2011-10-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits) vlan: allow nested vlan_do_receive() ipv6: fix route lookup in addrconf_prefix_rcv() bonding: eliminate bond_close race conditions qlcnic: fix beacon and LED test. qlcnic: Updated License file qlcnic: updated reset sequence qlcnic: reset loopback mode if promiscous mode setting fails. qlcnic: skip IDC ack check in fw reset path. i825xx: Fix incorrect dependency for BVME6000_NET ipv6: fix route error binding peer in func icmp6_dst_alloc ipv6: fix error propagation in ip6_ufo_append_data() stmmac: update normal descriptor structure (v2) stmmac: fix NULL pointer dereference in capabilities fixup (v2) stmmac: fix a bug while checking the HW cap reg (v2) be2net: Changing MAC Address of a VF was broken. be2net: Refactored be_cmds.c file. bnx2x: update driver version to 1.70.30-0 bnx2x: use FW 7.0.29.0 bnx2x: Enable changing speed when port type is PORT_DA bnx2x: Fix 54618se LED behavior ...