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2014-10-15Merge tag 'clk-for-linus-3.18' of ↵Linus Torvalds
git://git.linaro.org/people/mike.turquette/linux Pull clock tree updates from Mike Turquette: "The clk tree changes for 3.18 are dominated by clock drivers. Mostly fixes and enhancements to existing drivers as well as new drivers. This tag contains a bit more arch code than I usually take due to some OMAP2+ changes. Additionally it contains the restart notifier handlers which are merged as a dependency into several trees. The PXA changes are the only messy part. Due to having a stable tree I had to revert one patch and follow up with one more fix near the tip of this tag. Some dead code is introduced but it will soon become live code after 3.18-rc1 is released as the rest of the PXA family is converted over to the common clock framework. Another trend in this tag is that multiple vendors have started to push the complexity of changing their CPU frequency into the clock driver, whereas this used to be done in CPUfreq drivers. Changes to the clk core include a generic gpio-clock type and a clk_set_phase() function added to the top-level clk.h api. Due to some confusion on the fbdev mailing list the kernel boot parameters documentation was updated to further explain the clk_ignore_unused parameter, which is often required by users of the simplefb driver. Finally some fixes to the locking around the clock debugfs stuff was done to prevent deadlocks when interacting with other subsystems." * tag 'clk-for-linus-3.18' of git://git.linaro.org/people/mike.turquette/linux: (99 commits) clk: pxa clocks build system fix Revert "arm: pxa: Transition pxa27x to clk framework" clk: samsung: register restart handlers for s3c2412 and s3c2443 clk: rockchip: add restart handler clk: rockchip: rk3288: i2s_frac adds flag to set parent's rate doc/kernel-parameters.txt: clarify clk_ignore_unused arm: pxa: Transition pxa27x to clk framework dts: add devicetree bindings for pxa27x clocks clk: add pxa27x clock drivers arm: pxa: add clock pll selection bits clk: dts: document pxa clock binding clk: add pxa clocks infrastructure clk: gpio-gate: Ensure gpiod_ APIs are prototyped clk: ti: dra7-atl-clock: Mark the device as pm_runtime_irq_safe clk: ti: LLVMLinux: Move __init outside of type definition clk: ti: consider the fact that of_clk_get() might return an error clk: ti: dra7-atl-clock: fix a memory leak clk: ti: change clock init to use generic of_clk_init clk: hix5hd2: add I2C clocks clk: hix5hd2: add watchdog0 clocks ...
2014-10-13Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main changes in this cycle were: - changes related to No-CBs CPUs and NO_HZ_FULL - RCU-tasks implementation - torture-test updates - miscellaneous fixes - locktorture updates - RCU documentation updates" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits) workqueue: Use cond_resched_rcu_qs macro workqueue: Add quiescent state between work items locktorture: Cleanup header usage locktorture: Cannot hold read and write lock locktorture: Fix __acquire annotation for spinlock irq locktorture: Support rwlocks rcu: Eliminate deadlock between CPU hotplug and expedited grace periods locktorture: Document boot/module parameters rcutorture: Rename rcutorture_runnable parameter locktorture: Add test scenario for rwsem_lock locktorture: Add test scenario for mutex_lock locktorture: Make torture scripting account for new _runnable name locktorture: Introduce torture context locktorture: Support rwsems locktorture: Add infrastructure for torturing read locks torture: Address race in module cleanup locktorture: Make statistics generic locktorture: Teach about lock debugging locktorture: Support mutexes locktorture: Add documentation ...
2014-10-12Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris. Mostly ima, selinux, smack and key handling updates. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits) integrity: do zero padding of the key id KEYS: output last portion of fingerprint in /proc/keys KEYS: strip 'id:' from ca_keyid KEYS: use swapped SKID for performing partial matching KEYS: Restore partial ID matching functionality for asymmetric keys X.509: If available, use the raw subjKeyId to form the key description KEYS: handle error code encoded in pointer selinux: normalize audit log formatting selinux: cleanup error reporting in selinux_nlmsg_perm() KEYS: Check hex2bin()'s return when generating an asymmetric key ID ima: detect violations for mmaped files ima: fix race condition on ima_rdwr_violation_check and process_measurement ima: added ima_policy_flag variable ima: return an error code from ima_add_boot_aggregate() ima: provide 'ima_appraise=log' kernel option ima: move keyring initialization to ima_init() PKCS#7: Handle PKCS#7 messages that contain no X.509 certs PKCS#7: Better handling of unsupported crypto KEYS: Overhaul key identification when searching for asymmetric keys KEYS: Implement binary asymmetric key ID handling ...
2014-10-09Merge branch 'akpm' (fixes from Andrew Morton)Linus Torvalds
Merge patch-bomb from Andrew Morton: - part of OCFS2 (review is laggy again) - procfs - slab - all of MM - zram, zbud - various other random things: arch, filesystems. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits) nosave: consolidate __nosave_{begin,end} in <asm/sections.h> include/linux/screen_info.h: remove unused ORIG_* macros kernel/sys.c: compat sysinfo syscall: fix undefined behavior kernel/sys.c: whitespace fixes acct: eliminate compile warning kernel/async.c: switch to pr_foo() include/linux/blkdev.h: use NULL instead of zero include/linux/kernel.h: deduplicate code implementing clamp* macros include/linux/kernel.h: rewrite min3, max3 and clamp using min and max alpha: use Kbuild logic to include <asm-generic/sections.h> frv: remove deprecated IRQF_DISABLED frv: remove unused cpuinfo_frv and friends to fix future build error zbud: avoid accessing last unused freelist zsmalloc: simplify init_zspage free obj linking mm/zsmalloc.c: correct comment for fullness group computation zram: use notify_free to account all free notifications zram: report maximum used memory zram: zram memory size limitation zsmalloc: change return value unit of zs_get_total_size_bytes zsmalloc: move pages_allocated to zs_pool ...
2014-10-09CMA: document cma=0Jean Delvare
It isn't obvious that CMA can be disabled on the kernel's command line, so document it. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> 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>
2014-10-09mm/slab_common: commonize slab merge logicJoonsoo Kim
Slab merge is good feature to reduce fragmentation. Now, it is only applied to SLUB, but, it would be good to apply it to SLAB. This patch is preparation step to apply slab merge to SLAB by commonizing slab merge logic. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09Merge tag 'pm+acpi-3.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael Wysocki: "Features-wise, to me the most important this time is a rework of wakeup interrupts handling in the core that makes them work consistently across all of the available sleep states, including suspend-to-idle. Many thanks to Thomas Gleixner for his help with this work. Second is an update of the generic PM domains code that has been in need of some care for quite a while. Unused code is being removed, DT support is being added and domains are now going to be attached to devices in bus type code in analogy with the ACPI PM domain. The majority of work here was done by Ulf Hansson who also has been the most active developer this time. Apart from this we have a traditional ACPICA update, this time to upstream version 20140828 and a few ACPI wakeup interrupts handling patches on top of the general rework mentioned above. There also are several cpufreq commits including renaming the cpufreq-cpu0 driver to cpufreq-dt, as this is what implements generic DT-based cpufreq support, and a new DT-based idle states infrastructure for cpuidle. In addition to that, the ACPI LPSS driver is updated, ACPI support for Apple machines is improved, a few bugs are fixed and a few cleanups are made all over. Finally, the Adaptive Voltage Scaling (AVS) subsystem now has a tree maintained by Kevin Hilman that will be merged through the PM tree. Numbers-wise, the generic PM domains update takes the lead this time with 32 non-merge commits, second is cpufreq (15 commits) and the 3rd place goes to the wakeup interrupts handling rework (13 commits). Specifics: - Rework the handling of wakeup IRQs by the IRQ core such that all of them will be switched over to "wakeup" mode in suspend_device_irqs() and in that mode the first interrupt will abort system suspend in progress or wake up the system if already in suspend-to-idle (or equivalent) without executing any interrupt handlers. Among other things that eliminates the wakeup-related motivation to use the IRQF_NO_SUSPEND interrupt flag with interrupts which don't really need it and should not use it (Thomas Gleixner and Rafael Wysocki) - Switch over ACPI to handling wakeup interrupts with the help of the new mechanism introduced by the above IRQ core rework (Rafael Wysocki) - Rework the core generic PM domains code to eliminate code that's not used, add DT support and add a generic mechanism by which devices can be added to PM domains automatically during enumeration (Ulf Hansson, Geert Uytterhoeven and Tomasz Figa). - Add debugfs-based mechanics for debugging generic PM domains (Maciej Matraszek). - ACPICA update to upstream version 20140828. Included are updates related to the SRAT and GTDT tables and the _PSx methods are in the METHOD_NAME list now (Bob Moore and Hanjun Guo). - Add _OSI("Darwin") support to the ACPI core (unfortunately, that can't really be done in a straightforward way) to prevent Thunderbolt from being turned off on Apple systems after boot (or after resume from system suspend) and rework the ACPI Smart Battery Subsystem (SBS) driver to work correctly with Apple platforms (Matthew Garrett and Andreas Noever). - ACPI LPSS (Low-Power Subsystem) driver update cleaning up the code, adding support for 133MHz I2C source clock on Intel Baytrail to it and making it avoid using UART RTS override with Auto Flow Control (Heikki Krogerus). - ACPI backlight updates removing the video_set_use_native_backlight quirk which is not necessary any more, making the code check the list of output devices returned by the _DOD method to avoid creating acpi_video interfaces that won't work and adding a quirk for Lenovo Ideapad Z570 (Hans de Goede, Aaron Lu and Stepan Bujnak) - New Win8 ACPI OSI quirks for some Dell laptops (Edward Lin) - Assorted ACPI code cleanups (Fabian Frederick, Rasmus Villemoes, Sudip Mukherjee, Yijing Wang, and Zhang Rui) - cpufreq core updates and cleanups (Viresh Kumar, Preeti U Murthy, Rasmus Villemoes) - cpufreq driver updates: cpufreq-cpu0/cpufreq-dt (driver name change among other things), ppc-corenet, powernv (Viresh Kumar, Preeti U Murthy, Shilpasri G Bhat, Lucas Stach) - cpuidle support for DT-based idle states infrastructure, new ARM64 cpuidle driver, cpuidle core cleanups (Lorenzo Pieralisi, Rasmus Villemoes) - ARM big.LITTLE cpuidle driver updates: support for DT-based initialization and Exynos5800 compatible string (Lorenzo Pieralisi, Kevin Hilman) - Rework of the test_suspend kernel command line argument and a new trace event for console resume (Srinivas Pandruvada, Todd E Brandt) - Second attempt to optimize swsusp_free() (hibernation core) to make it avoid going through all PFNs which may be way too slow on some systems (Joerg Roedel) - devfreq updates (Paul Bolle, Punit Agrawal, Ãrjan Eide). - rockchip-io Adaptive Voltage Scaling (AVS) driver and AVS entry update in MAINTAINERS (Heiko Stübner, Kevin Hilman) - PM core fix related to clock management (Geert Uytterhoeven) - PM core's sysfs code cleanup (Johannes Berg)" * tag 'pm+acpi-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (105 commits) ACPI / fan: printk replacement PM / clk: Fix crash in clocks management code if !CONFIG_PM_RUNTIME PM / Domains: Rename cpu_data to cpuidle_data cpufreq: cpufreq-dt: fix potential double put of cpu OF node cpufreq: cpu0: rename driver and internals to 'cpufreq_dt' PM / hibernate: Iterate over set bits instead of PFNs in swsusp_free() cpufreq: ppc-corenet: remove duplicate update of cpu_data ACPI / sleep: Rework the handling of ACPI GPE wakeup from suspend-to-idle PM / sleep: Rename platform suspend/resume functions in suspend.c PM / sleep: Export dpm_suspend_late/noirq() and dpm_resume_early/noirq() ACPICA: Introduce acpi_enable_all_wakeup_gpes() ACPICA: Clear all non-wakeup GPEs in acpi_hw_enable_wakeup_gpe_block() ACPI / video: check _DOD list when creating backlight devices PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h cpufreq: Replace strnicmp with strncasecmp cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec cpufreq: powernv: Set the pstate of the last hotplugged out cpu in policy->cpus to minimum cpufreq: Allow stop CPU callback to be used by all cpufreq drivers PM / devfreq: exynos: Enable building exynos PPMU as module PM / devfreq: Export helper functions for drivers ...
2014-10-08Merge tag 'tty-3.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here's the big tty/serial driver patchset for 3.18-rc1. Lots of little things in here, some good work from Peter Hurley on the tty core, and in lots of drivers. There are also lots of other driver updates in here as well, full details in the changelogs. All have been in the linux-next tree for a while" * tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (99 commits) Revert "serial/core: Initialize the console pm state" tty: serial: 8250: use 32bit variable for rpm_tx_active tty: serial: msm: Add earlycon support serial/core: Initialize the console pm state serial: asc: Conditionally use readl_relaxed (COMPILE_TEST) serial: of-serial: add PM suspend/resume support m68k: AMIGA_BUILTIN_SERIAL should depend on TTY asm/uapi: Add definition of TIOC[SG]RS485 tty/metag_da: Add console_poll module parameter serial: 8250_pci: remove rts_n override from Baytrail quirk serial: cadence: Add generic earlycon support serial: imx: change the wait even to interruptiable serial: imx: terminate the RX DMA when the UART is suspending serial: imx: fix throttle/unthrottle callbacks for hardware assisted flow control serial: 8250: Add Quark X1000 to 8250_pci.c tty: omap-serial: pull out calculation from baud_is_mode16 tty: omap-serial: fix division by zero xen_hvc: no reason to write the type key on xenstore tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx() tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused() ...
2014-10-02Merge branch 'next' of ↵James Morris
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next
2014-09-30doc/kernel-parameters.txt: clarify clk_ignore_unusedMike Turquette
Refine the definition around clk_ignore_unused, which caused some confusion recently on the linux-fbdev and linux-arm-kernel mailing lists[0]. [0] http://lkml.kernel.org/r/<20140929135358.GC30998@ulmo> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-10-01Merge commit 'v3.16' into nextJames Morris
2014-09-29Merge back earlier 'pm-sleep' material for v3.18.Rafael J. Wysocki
2014-09-28tty: serial: msm: Add earlycon supportStephen Boyd
Add support for DT based and command line based early console on platforms with the msm serial hardware. Cc: Rob Herring <robh@kernel.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28serial: cadence: Add generic earlycon supportMichal Simek
Add earlycon support for the cadence serial port. This is based on recent patches: "tty/serial: pl011: add generic earlycon support" (sha1: 0d3c673e7881e691991b2a4745bd4f149603baa2) "tty/serial: add arm/arm64 semihosting earlycon" (sha1: d50d7269ebcb438afa346cdffce0f4e2a1b9e831) Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23uas: Add no-report-opcodes quirkHans de Goede
Besides the ASM1051 (*) needing sdev->no_report_opcodes = 1, it turns out that the JMicron JMS567 also needs it to work properly with uas (usb-storage always sets it). Since some of the scsi devs were not to keen on the idea to outrightly set sdev->no_report_opcodes = 1 for all uas devices, so add a quirk for this, and set it for the JMS567. *) Which has become a non-issue since we've completely blacklisted uas on the ASM1051 for other reasons Cc: stable@vger.kernel.org Reported-and-tested-by: Claudio Bizzarri <claudio.bizzarri@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23uas: Add a quirk for rejecting ATA_12 and ATA_16 commandsHans de Goede
And set this quirk for the Seagate Expansion Desk (0bc2:2312), as that one seems to hang upon receiving an ATA_12 or ATA_16 command. https://bugzilla.kernel.org/show_bug.cgi?id=79511 https://bbs.archlinux.org/viewtopic.php?id=183190 While at it also add missing documentation for the u value for usb-storage quirks. Cc: stable@vger.kernel.org # 3.16, 3.17 Signed-off-by: Hans de Goede <hdegoede@redhat.com> -- Changes in v2: Add documentation for new t and u usb-storage.quirks flags Changes in v3: Fix typo in documentation Changes in v4: Also apply the quirk to (0bc2:3312) Changes in v5: Rebased on 3.17-rc5, drop u documentation, already upstream Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23Merge branch 'rcu/next' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull the v3.18 RCU changes from Paul E. McKenney: " * Update RCU documentation. These were posted to LKML at https://lkml.org/lkml/2014/8/28/378. * Miscellaneous fixes. These were posted to LKML at https://lkml.org/lkml/2014/8/28/386. An additional fix that eliminates a documented (but now inconvenient) deadlock between RCU hotplug and expedited grace periods was posted at https://lkml.org/lkml/2014/8/28/573. * Changes related to No-CBs CPUs and NO_HZ_FULL. These were posted to LKML at https://lkml.org/lkml/2014/8/28/412. * Torture-test updates. These were posted to LKML at https://lkml.org/lkml/2014/8/28/546 and at https://lkml.org/lkml/2014/9/11/1114. * RCU-tasks implementation. These were posted to LKML at https://lkml.org/lkml/2014/8/28/540. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-17ima: provide 'ima_appraise=log' kernel optionDmitry Kasatkin
The kernel boot parameter "ima_appraise" currently defines 'off', 'enforce' and 'fix' modes. When designing a policy and labeling the system, access to files are either blocked in the default 'enforce' mode or automatically fixed in the 'fix' mode. It is beneficial to be able to run the system in a logging only mode, without fixing it, in order to properly analyze the system. This patch adds a 'log' mode to run the system in a permissive mode and log the appraisal results. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-16locktorture: Document boot/module parametersPaul E. McKenney
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-16rcutorture: Rename rcutorture_runnable parameterPaul E. McKenney
This commit changes rcutorture_runnable to torture_runnable, which is consistent with the names of the other parameters and is a bit shorter as well. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-16Merge branch 'rcu-tasks.2014.09.10a' into HEADPaul E. McKenney
rcu-tasks.2014.09.10a: Add RCU-tasks flavor of RCU.
2014-09-09PM / sleep: Update test_suspend option documentationSrinivas Pandruvada
Updated documentation to add freeze mode and repeat capability. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-08USB: document the 'u' flag for usb-storage quirks parameterAlan Stern
Commit d24d481b7d36 (usb-storage: Modify and export adjust_quirks so that it can be used by uas) added the 'u' flag to the quirks module parameter for usb-storage, but neglected to update the documentation. This patch adds the documentation. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@vger.kernel.org> # 3.15+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-07rcu: Add stall-warning checks for RCU-tasksPaul E. McKenney
This commit adds a ten-minute RCU-tasks stall warning. The actual time is controlled by the boot/sysfs parameter rcu_task_stall_timeout, with values less than or equal to zero disabling the stall warnings. The default value is ten minutes, which means that the tasks that have not yet responded will get their stacks dumped every ten minutes, until they pass through a voluntary context switch. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-07rcutorture: Add callback-flood testPaul E. McKenney
Although RCU is designed to handle arbitrary floods of callbacks, this capability is not routinely tested. This commit therefore adds a cbflood capability in which kthreads repeatedly registers large numbers of callbacks. One such kthread is created for each four CPUs (rounding up), and the test may be controlled by several cbflood_* kernel boot parameters, which control the number of bursts per flood, the number of callbacks per burst, the time between bursts, and the time between floods. The default values are large enough to exercise RCU's emergency responses to callback flooding. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David Miller <davem@davemloft.net> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-08-13Merge branch 'x86-xsave-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/xsave changes from Peter Anvin: "This is a patchset to support the XSAVES instruction required to support context switch of supervisor-only features in upcoming silicon. This patchset missed the 3.16 merge window, which is why it is based on 3.15-rc7" * 'x86-xsave-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, xsave: Add forgotten inline annotation x86/xsaves: Clean up code in xstate offsets computation in xsave area x86/xsave: Make it clear that the XSAVE macros use (%edi)/(%rdi) Define kernel API to get address of each state in xsave area x86/xsaves: Enable xsaves/xrstors x86/xsaves: Call booting time xsaves and xrstors in setup_init_fpu_buf x86/xsaves: Save xstate to task's xsave area in __save_fpu during booting time x86/xsaves: Add xsaves and xrstors support for booting time x86/xsaves: Clear reserved bits in xsave header x86/xsaves: Use xsave/xrstor for saving and restoring user space context x86/xsaves: Use xsaves/xrstors for context switch x86/xsaves: Use xsaves/xrstors to save and restore xsave area x86/xsaves: Define a macro for handling xsave/xrstor instruction fault x86/xsaves: Define macros for xsave instructions x86/xsaves: Change compacted format xsave area header x86/alternative: Add alternative_input_2 to support alternative with two features and input x86/xsaves: Add a kernel parameter noxsaves to disable xsaves/xrstors
2014-08-07Merge tag 'stable/for-linus-3.17-rc0-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen updates from David Vrabel: - remove unused V2 grant table support - note that Konrad is xen-blkkback/front maintainer - add 'xen_nopv' option to disable PV extentions for x86 HVM guests - misc minor cleanups * tag 'stable/for-linus-3.17-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-pciback: Document the 'quirks' sysfs file xen/pciback: Fix error return code in xen_pcibk_attach() xen/events: drop negativity check of unsigned parameter xen/setup: Remove Identity Map Debug Message xen/events/fifo: remove a unecessary use of BM() xen/events/fifo: ensure all bitops are properly aligned even on x86 xen/events/fifo: reset control block and local HEADs on resume xen/arm: use BUG_ON xen/grant-table: remove support for V2 tables x86/xen: safely map and unmap grant frames when in atomic context MAINTAINERS: Make me the Xen block subsystem (front and back) maintainer xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests.
2014-08-07Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main pull request for 3.17. It contains: - misc Cavium Octeon, BCM47xx, BCM63xx and Alchemy updates - MIPS ptrace updates and cleanups - various fixes that will also go to -stable - a number of cleanups and small non-critical fixes. - NUMA support for the Loongson 3. - more support for MSA - support for MAAR - various FP enhancements and fixes" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (139 commits) MIPS: jz4740: remove unnecessary null test before debugfs_remove MIPS: Octeon: remove unnecessary null test before debugfs_remove_recursive MIPS: ZBOOT: implement stack protector in compressed boot phase MIPS: mipsreg: remove duplicate MIPS_CONF4_FTLBSETS_SHIFT MIPS: Bonito64: remove a duplicate define MIPS: Malta: initialise MAARs MIPS: Initialise MAARs MIPS: detect presence of MAARs MIPS: define MAAR register accessors & bits MIPS: mark MSA experimental MIPS: Don't build MSA support unless it can be used MIPS: consistently clear MSA flags when starting & copying threads MIPS: 16 byte align MSA vector context MIPS: disable preemption whilst initialising MSA MIPS: ensure MSA gets disabled during boot MIPS: fix read_msa_* & write_msa_* functions on non-MSA toolchains MIPS: fix MSA context for tasks which don't use FP first MIPS: init upper 64b of vector registers when MSA is first used MIPS: save/disable MSA in lose_fpu MIPS: preserve scalar FP CSR when switching vector context ...
2014-08-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "Mostly cleanups and bug-fixes, with two exceptions. The first is lazy flushing of I/O-TLBs for PCI to improve performance, the second is software dirty bits in the pmd for the madvise-free implementation" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (24 commits) s390/locking: Reenable optimistic spinning s390/mm: implement dirty bits for large segment table entries KVM: s390/mm: Fix page table locking vs. split pmd lock s390/dasd: fix camel case s390/3215: fix hanging console issue s390/irq: improve displayed interrupt order in /proc/interrupts s390/seccomp: fix error return for filtered system calls s390/pci: introduce lazy IOTLB flushing for DMA unmap dasd: fix error recovery for alias devices during format dasd: fix list_del corruption during format dasd: fix unresponsive device during format dasd: use aliases for formatted devices during format s390/pci: fix kmsg component s390/kdump: Return NOTIFY_OK for all actions other than MEM_GOING_OFFLINE s390/watchdog: Fix module name in Kconfig help text s390/dasd: replace seq_printf by seq_puts s390/dasd: replace pr_warning by pr_warn s390/dasd: Move EXPORT_SYMBOL after function/variable s390/dasd: remove unnecessary null test before debugfs_remove s390/zfcp: use qdio buffer helpers ...
2014-08-06printk: allow increasing the ring buffer depending on the number of CPUsLuis R. Rodriguez
The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "In this release: - PKCS#7 parser for the key management subsystem from David Howells - appoint Kees Cook as seccomp maintainer - bugfixes and general maintenance across the subsystem" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (94 commits) X.509: Need to export x509_request_asymmetric_key() netlabel: shorter names for the NetLabel catmap funcs/structs netlabel: fix the catmap walking functions netlabel: fix the horribly broken catmap functions netlabel: fix a problem when setting bits below the previously lowest bit PKCS#7: X.509 certificate issuer and subject are mandatory fields in the ASN.1 tpm: simplify code by using %*phN specifier tpm: Provide a generic means to override the chip returned timeouts tpm: missing tpm_chip_put in tpm_get_random() tpm: Properly clean sysfs entries in error path tpm: Add missing tpm_do_selftest to ST33 I2C driver PKCS#7: Use x509_request_asymmetric_key() Revert "selinux: fix the default socket labeling in sock_graft()" X.509: x509_request_asymmetric_keys() doesn't need string length arguments PKCS#7: fix sparse non static symbol warning KEYS: revert encrypted key change ima: add support for measuring and appraising firmware firmware_class: perform new LSM checks security: introduce kernel_fw_from_file hook PKCS#7: Missing inclusion of linux/err.h ...
2014-08-04Merge tag 'staging-3.17-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging driver updates from Greg KH: "Here's the big pull request for the staging driver tree for 3.17-rc1. Lots of things in here, over 2000 patches, but the best part is this: 1480 files changed, 39070 insertions(+), 254659 deletions(-) Thanks to the great work of Kristina Martšenko, 14 different staging drivers have been removed from the tree as they were obsolete and no one was willing to work on cleaning them up. Other than the driver removals, loads of cleanups are in here (comedi, lustre, etc.) as well as the usual IIO driver updates and additions. All of this has been in the linux-next tree for a while" * tag 'staging-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (2199 commits) staging: comedi: addi_apci_1564: remove diagnostic interrupt support code staging: comedi: addi_apci_1564: add subdevice to check diagnostic status staging: wlan-ng: coding style problem fix staging: wlan-ng: fixing coding style problems staging: comedi: ii_pci20kc: request and ioremap memory staging: lustre: bitwise vs logical typo staging: dgnc: Remove unneeded dgnc_trace.c and dgnc_trace.h staging: dgnc: rephrase comment staging: comedi: ni_tio: remove some dead code staging: rtl8723au: Fix static symbol sparse warning staging: rtl8723au: usb_dvobj_init(): Remove unused variable 'pdev_desc' staging: rtl8723au: Do not duplicate kernel provided USB macros staging: rtl8723au: Remove never set struct pwrctrl_priv.bHWPowerdown staging: rtl8723au: Remove two never set variables staging: rtl8723au: RSSI_test is never set staging:r8190: coding style: Fixed checkpatch reported Error staging:r8180: coding style: Fixed too long lines staging:r8180: coding style: Fixed commenting style staging: lustre: ptlrpc: lproc_ptlrpc.c - fix dereferenceing user space buffer staging: lustre: ldlm: ldlm_resource.c - fix dereferenceing user space buffer ...
2014-08-04Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU changes from Ingo Molar: "The main changes: - torture-test updates - callback-offloading changes - maintainership changes - update RCU documentation - miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) rcu: Allow for NULL tick_nohz_full_mask when nohz_full= missing rcu: Fix a sparse warning in rcu_report_unblock_qs_rnp() rcu: Fix a sparse warning in rcu_initiate_boost() rcu: Fix __rcu_reclaim() to use true/false for bool rcu: Remove CONFIG_PROVE_RCU_DELAY rcu: Use __this_cpu_read() instead of per_cpu_ptr() rcu: Don't use NMIs to dump other CPUs' stacks rcu: Bind grace-period kthreads to non-NO_HZ_FULL CPUs rcu: Simplify priority boosting by putting rt_mutex in rcu_node rcu: Check both root and current rcu_node when setting up future grace period rcu: Allow post-unlock reference for rt_mutex rcu: Loosen __call_rcu()'s rcu_head alignment constraint rcu: Eliminate read-modify-write ACCESS_ONCE() calls rcu: Remove redundant ACCESS_ONCE() from tick_do_timer_cpu rcu: Make rcu node arrays static const char * const signal: Explain local_irq_save() call rcu: Handle obsolete references to TINY_PREEMPT_RCU rcu: Document deadlock-avoidance information for rcu_read_unlock() scripts: Teach get_maintainer.pl about the new "R:" tag rcu: Update rcu torture maintainership filename patterns ...
2014-08-04Merge tag 'trace-3.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This pull request has a lot of work done. The main thing is the changes to the ftrace function callback infrastructure. It's introducing a way to allow different functions to call directly different trampolines instead of all calling the same "mcount" one. The only user of this for now is the function graph tracer, which always had a different trampoline, but the function tracer trampoline was called and did basically nothing, and then the function graph tracer trampoline was called. The difference now, is that the function graph tracer trampoline can be called directly if a function is only being traced by the function graph trampoline. If function tracing is also happening on the same function, the old way is still done. The accounting for this takes up more memory when function graph tracing is activated, as it needs to keep track of which functions it uses. I have a new way that wont take as much memory, but it's not ready yet for this merge window, and will have to wait for the next one. Another big change was the removal of the ftrace_start/stop() calls that were used by the suspend/resume code that stopped function tracing when entering into suspend and resume paths. The stop of ftrace was done because there was some function that would crash the system if one called smp_processor_id()! The stop/start was a big hammer to solve the issue at the time, which was when ftrace was first introduced into Linux. Now ftrace has better infrastructure to debug such issues, and I found the problem function and labeled it with "notrace" and function tracing can now safely be activated all the way down into the guts of suspend and resume Other changes include clean ups of uprobe code, clean up of the trace_seq() code, and other various small fixes and clean ups to ftrace and tracing" * tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits) ftrace: Add warning if tramp hash does not match nr_trampolines ftrace: Fix trampoline hash update check on rec->flags ring-buffer: Use rb_page_size() instead of open coded head_page size ftrace: Rename ftrace_ops field from trampolines to nr_trampolines tracing: Convert local function_graph functions to static ftrace: Do not copy old hash when resetting tracing: let user specify tracing_thresh after selecting function_graph ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on() tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST s390/ftrace: remove check of obsolete variable function_trace_stop arm64, ftrace: Remove check of obsolete variable function_trace_stop Blackfin: ftrace: Remove check of obsolete variable function_trace_stop metag: ftrace: Remove check of obsolete variable function_trace_stop microblaze: ftrace: Remove check of obsolete variable function_trace_stop MIPS: ftrace: Remove check of obsolete variable function_trace_stop parisc: ftrace: Remove check of obsolete variable function_trace_stop sh: ftrace: Remove check of obsolete variable function_trace_stop sparc64,ftrace: Remove check of obsolete variable function_trace_stop tile: ftrace: Remove check of obsolete variable function_trace_stop ftrace: x86: Remove check of obsolete variable function_trace_stop ...
2014-08-02MIPS: Document the cca= command-line parameterFlorian Fainelli
Commit 351336929ccf222ae38ff0cb7a8dd5fd5c6236a0 ("[MIPS] Allow setting of the cache attribute at run time") introduced the 'cca=' kernel command-line parameter which allows overriding the kernel pages cacheable attributes, document that parameter. [ralf@linux-mips.org: replace @mips.com email addresses with it's imgtec.com equivalent in this commit message. Rephrase slightly for a bit more pedantic correctness.] Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Cc: linux-mips@linux-mips.org Cc: blogic@openwrt.org Cc: anemo@mba.ocn.ne.jp Cc: chris.dearman@imgtec.com Patchwork: https://patchwork.linux-mips.org/patch/7182/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-07-22s390/pci: introduce lazy IOTLB flushing for DMA unmapGerald Schaefer
This changes the default IOTLB flushing method to lazy flushing, which means that there will be no direct flush after each DMA unmap operation. Instead, the iommu bitmap pointer will be adjusted after unmap, so that no DMA address will be re-used until after an iommu bitmap wrap-around. The only IOTLB flush will then happen after each wrap-around. A new kernel parameter "s390_iommu=" is also introduced, to allow changing the flushing behaviour to the old strict method. Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-07-19Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU fixes from Thomas Gleixner: "Two RCU patches: - Address a serious performance regression on open/close caused by commit ac1bea85781e ("Make cond_resched() report RCU quiescent states") - Export RCU debug functions. Not a regression, but enablement to address a serious recursion bug in the sl*b allocators in 3.17" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu: Reduce overhead of cond_resched() checks for RCU rcu: Export debug_init_rcu_head() and and debug_init_rcu_head()
2014-07-17KEYS: validate certificate trust only with builtin keysDmitry Kasatkin
Instead of allowing public keys, with certificates signed by any key on the system trusted keyring, to be added to a trusted keyring, this patch further restricts the certificates to those signed only by builtin keys on the system keyring. This patch defines a new option 'builtin' for the kernel parameter 'keys_ownerid' to allow trust validation using builtin keys. Simplified Mimi's "KEYS: define an owner trusted keyring" patch Changelog v7: - rename builtin_keys to use_builtin_keys Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17KEYS: validate certificate trust only with selected keyDmitry Kasatkin
Instead of allowing public keys, with certificates signed by any key on the system trusted keyring, to be added to a trusted keyring, this patch further restricts the certificates to those signed by a particular key on the system keyring. This patch defines a new kernel parameter 'ca_keys' to identify the specific key which must be used for trust validation of certificates. Simplified Mimi's "KEYS: define an owner trusted keyring" patch. Changelog: - support for builtin x509 public keys only - export "asymmetric_keyid_match" - remove ifndefs MODULE - rename kernel boot parameter from keys_ownerid to ca_keys Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17ima: introduce multi-page collect buffersDmitry Kasatkin
Use of multiple-page collect buffers reduces: 1) the number of block IO requests 2) the number of asynchronous hash update requests Second is important for HW accelerated hashing, because significant amount of time is spent for preparation of hash update operation, which includes configuring acceleration HW, DMA engine, etc... Thus, HW accelerators are more efficient when working on large chunks of data. This patch introduces usage of multi-page collect buffers. Buffer size can be specified using 'ahash_bufsize' module parameter. Default buffer size is 4096 bytes. Changes in v3: - kernel parameter replaced with module parameter Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17ima: use ahash API for file hash calculationDmitry Kasatkin
Async hash API allows the use of HW acceleration for hash calculation. It may give significant performance gain and/or reduce power consumption, which might be very beneficial for battery powered devices. This patch introduces hash calculation using ahash API. ahash performance depends on the data size and the particular HW. Depending on the specific system, shash performance may be better. This patch defines 'ahash_minsize' module parameter, which is used to define the minimal file size to use with ahash. If this minimum file size is not set or the file is smaller than defined by the parameter, shash will be used. Changes in v3: - kernel parameter replaced with module parameter - pr_crit replaced with pr_crit_ratelimited - more comment changes - Mimi Changes in v2: - ima_ahash_size became as ima_ahash - ahash pre-allocation moved out from __init code to be able to use ahash crypto modules. Ahash allocated once on the first use. - hash calculation falls back to shash if ahash allocation/calculation fails - complex initialization separated from variable declaration - improved comments Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17Merge branch 'rcu/next' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: * Update RCU documentation. * Miscellaneous fixes. * Maintainership changes. * Torture-test updates. * Callback-offloading changes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-14Revert "ACPI / video: change acpi-video brightness_switch_enabled default to 0"Rafael J. Wysocki
This reverts commit 886129a8eebeb (ACPI / video: change acpi-video brightness_switch_enabled default to 0) as it is reported to cause problems to happen. Fixes: 886129a8eebeb (ACPI / video: change acpi-video brightness_switch_enabled default to 0) Link: http://marc.info/?l=linux-acpi&m=140534286826819&w=2 Reported by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-14xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests.Konrad Rzeszutek Wilk
By default when CONFIG_XEN and CONFIG_XEN_PVHVM kernels are run, they will enable the PV extensions (drivers, interrupts, timers, etc) - which is the best option for the majority of use cases. However, in some cases (kexec not fully working, benchmarking) we want to disable Xen PV extensions. As such introduce the 'xen_nopv' parameter that will do it. This parameter is intended only for HVM guests as the Xen PV guests MUST boot with PV extensions. However, even if you use 'xen_nopv' on Xen PV guests it will be ignored. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> --- [v2: s/off/xen_nopv/ per Boris Ostrovsky recommendation.] [v3: Add Reviewed-by] [v4: Clarify that this is only for HVM guests]
2014-07-08Documentation/kernel-parameters: Remove obsolete ip2=Geert Uytterhoeven
The handling of ip2= in drivers/char/ip2/ip2base.c was moved to drivers/char/ip2/ip2main.c in commit 47babd4c6a16915aeb15d4216d91f03910572982 ("Char: merge ip2main and ip2base"). The ip2 driver was demoted to staging in commit 4a6514e6d096716fb7bedf238efaaca877e2a7e8 ("tty: move obsolete and broken tty drivers to drivers/staging/tty/"), and finally deleted in commit 51c9d654c2def97827395a7fbfd0c6f865c26544 ("Staging: delete tty drivers"). Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-07rcu: Parallelize and economize NOCB kthread wakeupsPaul E. McKenney
An 80-CPU system with a context-switch-heavy workload can require so many NOCB kthread wakeups that the RCU grace-period kthreads spend several tens of percent of a CPU just awakening things. This clearly will not scale well: If you add enough CPUs, the RCU grace-period kthreads would get behind, increasing grace-period latency. To avoid this problem, this commit divides the NOCB kthreads into leaders and followers, where the grace-period kthreads awaken the leaders each of whom in turn awakens its followers. By default, the number of groups of kthreads is the square root of the number of CPUs, but this default may be overridden using the rcutree.rcu_nocb_leader_stride boot parameter. This reduces the number of wakeups done per grace period by the RCU grace-period kthread by the square root of the number of CPUs, but of course by shifting those wakeups to the leaders. In addition, because the leaders do grace periods on behalf of their respective followers, the number of wakeups of the followers decreases by up to a factor of two. Instead of being awakened once when new callbacks arrive and again at the end of the grace period, the followers are awakened only at the end of the grace period. For a numerical example, in a 4096-CPU system, the grace-period kthread would awaken 64 leaders, each of which would awaken its 63 followers at the end of the grace period. This compares favorably with the 79 wakeups for the grace-period kthread on an 80-CPU system. Reported-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-07-01tracing: Add ftrace_graph_notrace boot parameterNamhyung Kim
The ftrace_graph_notrace option is for specifying notrace filter for function graph tracer at boot time. It can be altered after boot using set_graph_notrace file on the debugfs. Link: http://lkml.kernel.org/p/1402590233-22321-2-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-25Merge branch 'urgent.2014.06.23a' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent Pull RCU fixes from Paul E. McKenney: " This series includes the following: 1. Export a pair of debug-object interfaces for RCU that will allow the slab allocators to avoid a recursion bug located by Sasha Levin. Strictly speaking, this is not a regression, but it would be good to enable the fix. 2. Address a serious performance regression on an open/close micro-benchmark located by Dave Hansen. The offending commit is ac1bea85781e (Make cond_resched() report RCU quiescent states). " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-23kernel/watchdog.c: print traces for all cpus on lockup detectionAaron Tomlin
A 'softlockup' is defined as a bug that causes the kernel to loop in kernel mode for more than a predefined period to time, without giving other tasks a chance to run. Currently, upon detection of this condition by the per-cpu watchdog task, debug information (including a stack trace) is sent to the system log. On some occasions, we have observed that the "victim" rather than the actual "culprit" (i.e. the owner/holder of the contended resource) is reported to the user. Often this information has proven to be insufficient to assist debugging efforts. To avoid loss of useful debug information, for architectures which support NMI, this patch makes it possible to improve soft lockup reporting. This is accomplished by issuing an NMI to each cpu to obtain a stack trace. If NMI is not supported we just revert back to the old method. A sysctl and boot-time parameter is available to toggle this feature. [dzickus@redhat.com: add CONFIG_SMP in certain areas] [akpm@linux-foundation.org: additional CONFIG_SMP=n optimisations] [mq@suse.cz: fix warning] Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jan Moskyto Matejka <mq@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-23rcu: Reduce overhead of cond_resched() checks for RCUPaul E. McKenney
Commit ac1bea85781e (Make cond_resched() report RCU quiescent states) fixed a problem where a CPU looping in the kernel with but one runnable task would give RCU CPU stall warnings, even if the in-kernel loop contained cond_resched() calls. Unfortunately, in so doing, it introduced performance regressions in Anton Blanchard's will-it-scale "open1" test. The problem appears to be not so much the increased cond_resched() path length as an increase in the rate at which grace periods complete, which increased per-update grace-period overhead. This commit takes a different approach to fixing this bug, mainly by moving the RCU-visible quiescent state from cond_resched() to rcu_note_context_switch(), and by further reducing the check to a simple non-zero test of a single per-CPU variable. However, this approach requires that the force-quiescent-state processing send resched IPIs to the offending CPUs. These will be sent only once the grace period has reached an age specified by the boot/sysfs parameter rcutree.jiffies_till_sched_qs, or once the grace period reaches an age halfway to the point at which RCU CPU stall warnings will be emitted, whichever comes first. Reported-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Lameter <cl@gentwo.org> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> [ paulmck: Made rcu_momentary_dyntick_idle() as suggested by the ktest build robot. Also fixed smp_mb() comment as noted by Oleg Nesterov. ] Merge with e552592e (Reduce overhead of cond_resched() checks for RCU) Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>