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2016-02-29ata: ahci: don't mark HotPlugCapable Ports as external/removableManuel Lauss
The HPCP bit is set by bioses for on-board sata ports either because they think sata is hotplug capable in general or to allow Windows to display a "device eject" icon on ports which are routed to an external connector bracket. However in Redhat Bugzilla #1310682, users report that with kernel 4.4, where this bit test first appeared, a lot of partitions on sata drives are now mounted automatically. This patch should fix redhat and a lot of other distros which unconditionally automount all devices which have the "removable" bit set. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 8a3e33cf92c7 ("ata: ahci: find eSATA ports and flag them as removable" changes userspace behavior) Link: http://lkml.kernel.org/g/56CF35FA.1070500@redhat.com Cc: stable@vger.kernel.org #v4.4+
2016-02-29ahci: Workaround for ThunderX Errata#22536Tirumalesh Chalamarla
Due to Errata in ThunderX, HOST_IRQ_STAT should be cleared before leaving the interrupt handler. The patch attempts to satisfy the need. Changes from V2: - removed newfile - code is now under CONFIG_ARM64 Changes from V1: - Rebased on top of libata/for-4.6 - Moved ThunderX intr handler to new file tj: Minor adjustments to comments. Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-29USB: cp210x: Add ID for Parrot NMEA GPS Flight RecorderVittorio Alfieri
The Parrot NMEA GPS Flight Recorder is a USB composite device consisting of hub, flash storage, and cp210x usb to serial chip. It is an accessory to the mass-produced Parrot AR Drone 2. The device emits standard NMEA messages which make the it compatible with NMEA compatible software. It was tested using gpsd version 3.11-3 as an NMEA interpreter and using the official Parrot Flight Recorder. Signed-off-by: Vittorio Alfieri <vittorio88@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org>
2016-02-29USB: qcserial: add Dell Wireless 5809e Gobi 4G HSPA+ (rev3)Patrik Halfar
New revision of Dell Wireless 5809e Gobi 4G HSPA+ Mobile Broadband Card has new idProduct. Bus 002 Device 006: ID 413c:81b3 Dell Computer Corp. Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x413c Dell Computer Corp. idProduct 0x81b3 bcdDevice 0.06 iManufacturer 1 Sierra Wireless, Incorporated iProduct 2 Dell Wireless 5809e Gobi™ 4G HSPA+ Mobile Broadband Card iSerial 3 bNumConfigurations 2 Signed-off-by: Patrik Halfar <patrik_halfar@halfarit.cz> Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org>
2016-02-29use ->d_seq to get coherency between ->d_inode and ->d_flagsAl Viro
Games with ordering and barriers are way too brittle. Just bump ->d_seq before and after updating ->d_inode and ->d_flags type bits, so that verifying ->d_seq would guarantee they are coherent. Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-02-29ALSA: hdsp: Fix wrong boolean ctl value accessesTakashi Iwai
snd-hdsp driver accesses enum item values (int) instead of boolean values (long) wrongly for some ctl elements. This patch fixes them. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-29ALSA: hdspm: Fix zero-divisionTakashi Iwai
HDSPM driver contains a code issuing zero-division potentially in system sample rate ctl code. This patch fixes it by not processing a zero or invalid rate value as a divisor, as well as excluding the invalid value to be passed via the given ctl element. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-29ALSA: hdspm: Fix wrong boolean ctl value accessesTakashi Iwai
snd-hdspm driver accesses enum item values (int) instead of boolean values (long) wrongly for some ctl elements. This patch fixes them. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-29iommu/amd: Detach device from domain before removalJoerg Roedel
Detach the device that is about to be removed from its domain (if it has one) to clear any related state like DTE entry and device's ATS state. Reported-by: Kelly Zytaruk <Kelly.Zytaruk@amd.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-02-29MIPS: kvm: Fix ioctl error handling.Michael S. Tsirkin
Calling return copy_to_user(...) or return copy_from_user in an ioctl will not do the right thing if there's a pagefault: copy_to_user/copy_from_user return the number of bytes not copied in this case. Fix up kvm on mips to do return copy_to_user(...)) ? -EFAULT : 0; and return copy_from_user(...)) ? -EFAULT : 0; everywhere. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12709/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-02-29MIPS: scache: Fix scache init with invalid line size.Govindraj Raja
In current scache init cache line_size is determined from cpu config register, however if there there no scache then mips_sc_probe_cm3 function populates a invalid line_size of 2. The invalid line_size can cause a NULL pointer deference during r4k_dma_cache_inv as r4k_blast_scache is populated based on line_size. Scache line_size of 2 is invalid option in r4k_blast_scache_setup. This issue was faced during a MIPS I6400 based virtual platform bring up where scache was not available in virtual platform model. Signed-off-by: Govindraj Raja <Govindraj.Raja@imgtec.com> Fixes: 7d53e9c4cd21("MIPS: CM3: Add support for CM3 L2 cache.") Cc: Paul Burton <paul.burton@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hartley <James.Hartley@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.2+ Patchwork: https://patchwork.linux-mips.org/patch/12710/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-02-29tools lib traceevent: Split pevent_print_event() into specific functionality ↵Steven Rostedt
functions Currently there's a single function that is used to display a record's data in human readable format. That's pevent_print_event(). Unfortunately, this gives little room for adding other output within the line without updating that function call. I've decided to split that function into 3 parts. pevent_print_event_task() which prints the task comm, pid and the CPU pevent_print_event_time() which outputs the record's timestamp pevent_print_event_data() which outputs the rest of the event data. pevent_print_event() now simply calls these three functions. To save time from doing the search for event from the record's type, I created a new helper function called pevent_find_event_by_record(), which returns the record's event, and this event has to be passed to the above functions. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20160229090128.43a56704@gandalf.local.home Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-29tracing/syscalls: Rename "/format" tracepoint field name "nr" to "__syscall_nr:Taeung Song
Some tracepoint have multiple fields with the same name, "nr", the first one is a unique syscall ID, the other is a syscall argument: # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format name: sys_enter_io_getevents ID: 747 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:int nr; offset:8; size:4; signed:1; field:aio_context_t ctx_id; offset:16; size:8; signed:0; field:long min_nr; offset:24; size:8; signed:0; field:long nr; offset:32; size:8; signed:0; field:struct io_event * events; offset:40; size:8; signed:0; field:struct timespec * timeout; offset:48; size:8; signed:0; print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout)) # Fix it by renaming the "/format" common tracepoint field "nr" to "__syscall_nr". Signed-off-by: Taeung Song <treeze.taeung@gmail.com> [ Do not rename the struct member, just the '/format' field name ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160226132301.3ae065a4@gandalf.local.home Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-29perf trace: Check and discard not only 'nr' but also '__syscall_nr'Taeung Song
Format fields of a syscall have the first variable '__syscall_nr' or 'nr' that mean the syscall number. But it isn't relevant here so drop it. 'nr' among fields of syscall was renamed '__syscall_nr'. So add exception handling to drop '__syscall_nr' and modify the comment for this excpetion handling. Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Taeung Song <treeze.taeung@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1456492465-5946-1-git-send-email-treeze.taeung@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-29perf tools: Fix python extension buildJiri Olsa
The util/python-ext-sources file contains source files required to build the python extension relative to $(srctree)/tools/perf, Such a file path $(FILE).c is handed over to the python extension build system, which builds the final object in the $(PYTHON_EXTBUILD)/tmp/$(FILE).o path. After the build is done all files from $(PYTHON_EXTBUILD)lib/ are carried as the result binaries. Above system fails when we add source file relative to ../lib, which we do for: ../lib/bitmap.c ../lib/find_bit.c ../lib/hweight.c ../lib/rbtree.c All above objects will be built like: $(PYTHON_EXTBUILD)/tmp/../lib/bitmap.c $(PYTHON_EXTBUILD)/tmp/../lib/find_bit.c $(PYTHON_EXTBUILD)/tmp/../lib/hweight.c $(PYTHON_EXTBUILD)/tmp/../lib/rbtree.c which accidentally happens to be final library path: $(PYTHON_EXTBUILD)/lib/ Changing setup.py to pass full paths of source files to Extension build class and thus keep all built objects under $(PYTHON_EXTBUILD)tmp directory. Reported-by: Jeff Bastian <jbastian@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@vger.kernel.org # v4.2+ Link: http://lkml.kernel.org/r/20160227201350.GB28494@krava.redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-29cxl: Fix PSL timebase synchronization detectionFrederic Barrat
The PSL timebase synchronization is seemingly failing for configuration not including VIRT_CPU_ACCOUNTING_NATIVE. The driver shows the following trace in dmesg: PSL: Timebase sync: giving up! The PSL timebase register is actually syncing correctly, but the cxl driver is not detecting it. Fix is to use the proper timebase-to-time conversion. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> # 4.3+ Acked-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29MIPS: Avoid variant of .type unsupported by LLVM AssemblerDaniel Sanders
The target independent parts of the LLVM Lexer considers 'fault@function' to be a single token representing the 'fault' symbol with a 'function' modifier. However, this is not the case in the .type directive where 'function' refers to STT_FUNC from the ELF standard. Although GAS accepts it, '.type symbol@function' is an undocumented form of this directive. The documentation specifies a comma between the symbol and '@function'. Signed-off-by: Scott Egerton <Scott.Egerton@imgtec.com> Signed-off-by: Daniel Sanders <daniel.sanders@imgtec.com> Reviewed-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12587/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-02-29MIPS: jz4740: Fix surviving instance of irq_to_gpio()Ralf Baechle
This is fallout from commit 832f5dacfa0b ("MIPS: Remove all the uses of custom gpio.h"). Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Suggested-by: Lars-Peter Clausen <lars@metafoo.de>
2016-02-29arm/arm64: KVM: Fix ioctl error handlingMichael S. Tsirkin
Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up kvm to do return copy_to_user(...)) ? -EFAULT : 0; everywhere. Cc: stable@vger.kernel.org Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29locking/lockdep: Detect chain_key collisionsIngo Molnar
Add detection for chain_key collision under CONFIG_DEBUG_LOCKDEP. When a collision is detected the problem is reported and all lock debugging is turned off. Tested using liblockdep and the added tests before and after applying the fix, confirming both that the code added for the detection correctly reports the problem and that the fix actually fixes it. Tested tweaking lockdep to generate false collisions and verified that the problem is reported and that lock debugging is turned off. Also tested with lockdep's test suite after applying the patch: [ 0.000000] Good, all 253 testcases passed! | Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezernandez@gmail.com> Cc: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: sasha.levin@oracle.com Link: http://lkml.kernel.org/r/1455864533-7536-4-git-send-email-alfredoalvarezernandez@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29locking/lockdep: Prevent chain_key collisionsAlfredo Alvarez Fernandez
The chain_key hashing macro iterate_chain_key(key1, key2) does not generate a new different value if both key1 and key2 are 0. In that case the generated value is again 0. This can lead to collisions which can result in lockdep not detecting deadlocks or circular dependencies. Avoid the problem by using class_idx (1-based) instead of class id (0-based) as an input for the hashing macro 'key2' in iterate_chain_key(key1, key2). The use of class id created collisions in cases like the following: 1.- Consider an initial state in which no class has been acquired yet. Under these circumstances an AA deadlock will not be detected by lockdep: lock [key1,key2]->new key (key1=old chain_key, key2=id) -------------------------- A [0,0]->0 A [0,0]->0 (collision) The newly generated chain_key collides with the one used before and as a result the check for a deadlock is skipped A simple test using liblockdep and a pthread mutex confirms the problem: (omitting stack traces) new class 0xe15038: 0x7ffc64950f20 acquire class [0xe15038] 0x7ffc64950f20 acquire class [0xe15038] 0x7ffc64950f20 hash chain already cached, key: 0000000000000000 tail class: [0xe15038] 0x7ffc64950f20 2.- Consider an ABBA in 2 different tasks and no class yet acquired. T1 [key1,key2]->new key T2[key1,key2]->new key -- -- A [0,0]->0 B [0,1]->1 B [0,1]->1 (collision) A In this case the collision prevents lockdep from creating the new dependency A->B. This in turn results in lockdep not detecting the circular dependency when T2 acquires A. Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezernandez@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: sasha.levin@oracle.com Link: http://lkml.kernel.org/r/1455147212-2389-4-git-send-email-alfredoalvarezernandez@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29tools/lib/lockdep: Fix link creation warningIngo Molnar
This warning triggers if the .so library has already been linked: triton:~/tip/tools/lib/lockdep> make CC common.o CC lockdep.o CC rbtree.o LD liblockdep-in.o LD liblockdep.a ln: failed to create symbolic link ‘liblockdep.so’: File exists LD liblockdep.so.4.5.0-rc6 Overwrite the link. Cc: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29tools/lib/lockdep: Add tests for AA and ABBA lockingAlfredo Alvarez Fernandez
Add test for AA and 2 threaded ABBA locking. Rename AA.c to ABA.c since it was implementing an ABA instead of a pure AA. Now both cases are covered. The expected output for AA.c is that the process blocks and lockdep reports a deadlock. ABBA_2threads.c differs from ABBA.c in that lockdep keeps separate chains of held locks per task. This can lead to different behaviour regarding lock detection. The expected output for this test is that the process blocks and lockdep reports a circular locking dependency. These tests found a lockdep bug - fixed by the next commit. Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455864533-7536-3-git-send-email-alfredoalvarezernandez@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29tools/lib/lockdep: Add userspace version of READ_ONCE()Alfredo Alvarez Fernandez
This was added to the kernel code in <1658d35ead5d> ("list: Use READ_ONCE() when testing for empty lists"). There's nothing special we need to do about it in userspace. Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455864533-7536-2-git-send-email-alfredoalvarezernandez@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29tools/lib/lockdep: Fix the build on recent kernelsIngo Molnar
The following upstream commit: 4a389810bc3c ("kernel/locking/lockdep.c: convert hash tables to hlists") broke the tools/lib/lockdep build. Add trivial RCU wrappers to fix it. These wrappers should probably be moved into their own header file. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Krinkin <krinkin.m.u@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29locking/qspinlock: Move __ARCH_SPIN_LOCK_UNLOCKED to qspinlock_types.hDan Streetman
Move the __ARCH_SPIN_LOCK_UNLOCKED definition from qspinlock.h into qspinlock_types.h. The definition of __ARCH_SPIN_LOCK_UNLOCKED comes from the build arch's include files; but on x86 when CONFIG_QUEUED_SPINLOCKS=y, it just it's defined in asm-generic/qspinlock.h. In most cases, this doesn't matter because linux/spinlock.h includes asm/spinlock.h, which for x86 includes asm-generic/qspinlock.h. However, any code that only includes linux/mutex.h will break, because it only includes asm/spinlock_types.h. For example, this breaks systemtap, which only includes mutex.h. Signed-off-by: Dan Streetman <dan.streetman@canonical.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <Waiman.Long@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455907767-17821-1-git-send-email-dan.streetman@canonical.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29locking/mutex: Allow next waiter lockless wakeupDavidlohr Bueso
Make use of wake-queues and enable the wakeup to occur after releasing the wait_lock. This is similar to what we do with rtmutex top waiter, slightly shortening the critical region and allow other waiters to acquire the wait_lock sooner. In low contention cases it can also help the recently woken waiter to find the wait_lock available (fastpath) when it continues execution. Reviewed-by: Waiman Long <Waiman.Long@hpe.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Jason Low <jason.low2@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Waiman Long <waiman.long@hpe.com> Cc: Will Deacon <Will.Deacon@arm.com> Link: http://lkml.kernel.org/r/20160125022343.GA3322@linux-uzut.site Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29locking/pvqspinlock: Enable slowpath locking count trackingWaiman Long
This patch enables the tracking of the number of slowpath locking operations performed. This can be used to compare against the number of lock stealing operations to see what percentage of locks are stolen versus acquired via the regular slowpath. Signed-off-by: Waiman Long <Waiman.Long@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Douglas Hatch <doug.hatch@hpe.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1449778666-13593-2-git-send-email-Waiman.Long@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29locking/qspinlock: Use smp_cond_acquire() in pending codeWaiman Long
The newly introduced smp_cond_acquire() was used to replace the slowpath lock acquisition loop. Similarly, the new function can also be applied to the pending bit locking loop. This patch uses the new function in that loop. Signed-off-by: Waiman Long <Waiman.Long@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Douglas Hatch <doug.hatch@hpe.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1449778666-13593-1-git-send-email-Waiman.Long@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29locking/pvqspinlock: Move lock stealing count tracking code into ↵Waiman Long
pv_queued_spin_steal_lock() This patch moves the lock stealing count tracking code into pv_queued_spin_steal_lock() instead of via a jacket function simplifying the code. Signed-off-by: Waiman Long <Waiman.Long@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Douglas Hatch <doug.hatch@hpe.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1449778666-13593-3-git-send-email-Waiman.Long@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29locking/mcs: Fix mcs_spin_lock() orderingPeter Zijlstra
Similar to commit b4b29f94856a ("locking/osq: Fix ordering of node initialisation in osq_lock") the use of xchg_acquire() is fundamentally broken with MCS like constructs. Furthermore, it turns out we rely on the global transitivity of this operation because the unlock path observes the pointer with a READ_ONCE(), not an smp_load_acquire(). This is non-critical because the MCS code isn't actually used and mostly serves as documentation, a stepping stone to the more complex things we've build on top of the idea. Reported-by: Andrea Parri <parri.andrea@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Fixes: 3552a07a9c4a ("locking/mcs: Use acquire/release semantics") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29Merge tag 'v4.5-rc6' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/deadline: Remove superfluous call to switched_to_dl()Peter Zijlstra
if (A || B) { } else if (A && !B) { } If A we'll take the first branch, if !A we will not satisfy the second. Therefore the second branch will never be taken. Reported-by: luca abeni <luca.abeni@unitn.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160225140149.GK6357@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/debug: Fix preempt_disable_ip recording for preempt_disable()Sebastian Andrzej Siewior
The preempt_disable() invokes preempt_count_add() which saves the caller in ->preempt_disable_ip. It uses CALLER_ADDR1 which does not look for its caller but for the parent of the caller. Which means we get the correct caller for something like spin_lock() unless the architectures inlines those invocations. It is always wrong for preempt_disable() or local_bh_disable(). This patch makes the function get_lock_parent_ip() which tries CALLER_ADDR0,1,2 if the former is a locking function. This seems to record the preempt_disable() caller properly for preempt_disable() itself as well as for get_cpu_var() or local_bh_disable(). Steven asked for the get_parent_ip() -> get_lock_parent_ip() rename. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160226135456.GB18244@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched, time: Switch VIRT_CPU_ACCOUNTING_GEN to jiffy granularityRik van Riel
When profiling syscall overhead on nohz-full kernels, after removing __acct_update_integrals() from the profile, native_sched_clock() remains as the top CPU user. This can be reduced by moving VIRT_CPU_ACCOUNTING_GEN to jiffy granularity. This will reduce timing accuracy on nohz_full CPUs to jiffy based sampling, just like on normal CPUs. It results in totally removing native_sched_clock from the profile, and significantly speeding up the syscall entry and exit path, as well as irq entry and exit, and KVM guest entry & exit. Additionally, only call the more expensive functions (and advance the seqlock) when jiffies actually changed. This code relies on another CPU advancing jiffies when the system is busy. On a nohz_full system, this is done by a housekeeping CPU. A microbenchmark calling an invalid syscall number 10 million times in a row speeds up an additional 30% over the numbers with just the previous patches, for a total speedup of about 40% over 4.4 and 4.5-rc1. Run times for the microbenchmark: 4.4 3.8 seconds 4.5-rc1 3.7 seconds 4.5-rc1 + first patch 3.3 seconds 4.5-rc1 + first 3 patches 3.1 seconds 4.5-rc1 + all patches 2.3 seconds A non-NOHZ_FULL cpu (not the housekeeping CPU): all kernels 1.86 seconds Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: clark@redhat.com Cc: eric.dumazet@gmail.com Cc: fweisbec@gmail.com Cc: luto@amacapital.net Link: http://lkml.kernel.org/r/1455152907-18495-5-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29time, acct: Drop irq save & restore from __acct_update_integrals()Rik van Riel
It looks like all the call paths that lead to __acct_update_integrals() already have irqs disabled, and __acct_update_integrals() does not need to disable irqs itself. This is very convenient since about half the CPU time left in this function was spent in local_irq_save alone. Performance of a microbenchmark that calls an invalid syscall ten million times in a row on a nohz_full CPU improves 21% vs. 4.5-rc1 with both the removal of divisions from __acct_update_integrals() and this patch, with runtime dropping from 3.7 to 2.9 seconds. With these patches applied, the highest remaining cpu user in the trace is native_sched_clock, which is addressed in the next patch. For testing purposes I stuck a WARN_ON(!irqs_disabled()) test in __acct_update_integrals(). It did not trigger. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: clark@redhat.com Cc: eric.dumazet@gmail.com Cc: fweisbec@gmail.com Cc: luto@amacapital.net Link: http://lkml.kernel.org/r/1455152907-18495-4-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29acct, time: Change indentation in __acct_update_integrals()Rik van Riel
Change the indentation in __acct_update_integrals() to make the function a little easier to read. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Frederic Weisbecker <fweisbec@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: clark@redhat.com Cc: eric.dumazet@gmail.com Cc: fweisbec@gmail.com Cc: luto@amacapital.net Link: http://lkml.kernel.org/r/1455152907-18495-3-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched, time: Remove non-power-of-two divides from __acct_update_integrals()Rik van Riel
When running a microbenchmark calling an invalid syscall number in a loop, on a nohz_full CPU, we spend a full 9% of our CPU time in __acct_update_integrals(). This function converts cputime_t to jiffies, to a timeval, only to convert the timeval back to microseconds before discarding it. This patch leaves __acct_update_integrals() functionally equivalent, but speeds things up by about 12%, with 10 million calls to an invalid syscall number dropping from 3.7 to 3.25 seconds. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: clark@redhat.com Cc: eric.dumazet@gmail.com Cc: fweisbec@gmail.com Cc: luto@amacapital.net Link: http://lkml.kernel.org/r/1455152907-18495-2-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/rt: Kick RT bandwidth timer immediately on start upSteven Rostedt
I've been debugging why deadline tasks can cause the RT scheduler to throttle, even when the deadline tasks are only taking up 50% of the CPU and RT tasks are not even using 1% of the CPU. Here's what I found. In order to keep a CPU from being hogged by RT tasks, the deadline scheduler adds its run time (delta_exec) to the rt_time of the RT bandwidth. That way, if the two use more than 95% of the CPU within one second (default settings), the RT tasks are throttled to allow non RT tasks to run. Although the deadline tasks add their run time to the RT bandwidth, it lets the RT tasks do the accounting. This is where the problem lies. If a deadline task runs for a bit, and no RT tasks are running, then it will continually add to the RT rt_time that is used to calculate how much CPU the RT tasks use. But no RT period is in play, and this accumulation of the runtime never gets reset. When an RT task finally gets to run, and the watchdog goes off, it can see that the RT task has used more than it should of, because the deadline task added all this runtime to its rt_time. Then the RT task that just woke up gets throttled for no good reason. I also noticed that when an RT task is queued, it starts the timer to account for overload and such. But that timer goes off one period later, which may be too late and the extra rt_time will trigger a throttle. This is a quick work around to the problem. When a new RT task is queued, the bandwidth timer is set to go off immediately. Then the timer can clear out the extra time added to the rt_time while there was no RT task running. This stops my tests from triggering the throttle, and it will still throttle if an RT task runs too much, even while a deadline task is running. A better solution may be to subtract the bandwidth that the deadline task uses from the rt_runtime, and add it back when its finished. Then there wont be a need for runtime tracking of the time used by deadline tasks. I may play with that solution tomorrow. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <juri.lelli@gmail.com> Cc: <williams@redhat.com> Cc: Clark Williams Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Juri Lelli Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160216183746.349ec98b@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/debug: Add deadline scheduler bandwidth ratio to /proc/sched_debugSteven Rostedt (Red Hat)
Playing with SCHED_DEADLINE and cpusets, I found that I was unable to create new SCHED_DEADLINE tasks, with the error of EBUSY as if the bandwidth was already used up. I then realized there wa no way to see what bandwidth is used by the runqueues to debug the issue. By adding the dl_bw->bw and dl_bw->total_bw to the output of the deadline info in /proc/sched_debug, this allows us to see what bandwidth has been reserved and where a problem may exist. For example, before the issue we see the ratio of the bandwidth: # cat /proc/sys/kernel/sched_rt_runtime_us 950000 # cat /proc/sys/kernel/sched_rt_period_us 1000000 # grep dl /proc/sched_debug dl_rq[0]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[1]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[2]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[3]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[4]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[5]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[6]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[7]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 Note: (950000 / 1000000) << 20 == 996147 After I played with cpusets and hit the issue, the result is now: # grep dl /proc/sched_debug dl_rq[0]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[1]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 104857 dl_rq[2]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 104857 dl_rq[3]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 104857 dl_rq[4]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[5]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[6]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[7]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 This shows that there is definitely a problem as we should never have a negative total bandwidth. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160222212825.756849091@goodmis.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/debug: Move sched_domain_sysctl to debug.cSteven Rostedt (Red Hat)
The sched_domain_sysctl setup is only enabled when SCHED_DEBUG is configured. As debug.c is only compiled when SCHED_DEBUG is configured as well, move the setup of sched_domain_sysctl into that file. Note, the (un)register_sched_domain_sysctl() functions had to be changed from static to allow access to them from core.c. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160222212825.599278093@goodmis.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/debug: Move the /sys/kernel/debug/sched_features file setup into debug.cSteven Rostedt (Red Hat)
As /sys/kernel/debug/sched_features is only created when SCHED_DEBUG is enabled, and the file debug.c is only compiled when SCHED_DEBUG is enabled, it makes sense to move sched_feature setup into that file and get rid of the #ifdef. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160222212825.464193063@goodmis.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/rt: Fix PI handling vs. sched_setscheduler()Peter Zijlstra
Andrea Parri reported: > I found that the following scenario (with CONFIG_RT_GROUP_SCHED=y) is not > handled correctly: > > T1 (prio = 20) > lock(rtmutex); > > T2 (prio = 20) > blocks on rtmutex (rt_nr_boosted = 0 on T1's rq) > > T1 (prio = 20) > sys_set_scheduler(prio = 0) > [new_effective_prio == oldprio] > T1 prio = 20 (rt_nr_boosted = 0 on T1's rq) > > The last step is incorrect as T1 is now boosted (c.f., rt_se_boosted()); > in particular, if we continue with > > T1 (prio = 20) > unlock(rtmutex) > wakeup(T2) > adjust_prio(T1) > [prio != rt_mutex_getprio(T1)] > dequeue(T1) > rt_nr_boosted = (unsigned long)(-1) > ... > T1 prio = 0 > > then we end up leaving rt_nr_boosted in an "inconsistent" state. > > The simple program attached could reproduce the previous scenario; note > that, as a consequence of the presence of this state, the "assertion" > > WARN_ON(!rt_nr_running && rt_nr_boosted) > > from dec_rt_group() may trigger. So normally we dequeue/enqueue tasks in sched_setscheduler(), which would ensure the accounting stays correct. However in the early PI path we fail to do so. So this was introduced at around v3.14, by: c365c292d059 ("sched: Consider pi boosting in setscheduler()") which fixed another problem exactly because that dequeue/enqueue, joy. Fix this by teaching rt about DEQUEUE_SAVE/ENQUEUE_RESTORE and have it preserve runqueue location with that option. This requires decoupling the on_rt_rq() state from being on the list. In order to allow for explicit movement during the SAVE/RESTORE, introduce {DE,EN}QUEUE_MOVE. We still must use SAVE/RESTORE in these cases to preserve other invariants. Respecting the SAVE/RESTORE flags also has the (nice) side-effect that things like sys_nice()/sys_sched_setaffinity() also do not reorder FIFO tasks (whereas they used to before this patch). Reported-by: Andrea Parri <parri.andrea@gmail.com> Tested-by: Andrea Parri <parri.andrea@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/core: Remove duplicated sched_group_set_shares() prototypeDongsheng Yang
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <lizefan@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1452674558-31897-1-git-send-email-yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/fair: Consolidate nohz CPU load update codeFrederic Weisbecker
Lets factorize a bit of code there. We'll even have a third user soon. While at it, standardize the idle update function name against the others. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Byungchul Park <byungchul.park@lge.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1452700891-21807-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/fair: Avoid using decay_load_missed() with a negative valueByungchul Park
decay_load_missed() cannot handle nagative values, so we need to prevent using the function with a negative value. Reported-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: perterz@infradead.org Fixes: 59543275488d ("sched/fair: Prepare __update_cpu_load() to handle active tickless") Link: http://lkml.kernel.org/r/20160115070749.GA1914@X58A-UD3R Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29Merge branch 'sched/urgent' into sched/core, to pick up fixes before ↵Ingo Molnar
applying new changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/deadline: Always calculate end of period on sched_yield()Peter Zijlstra
Steven noticed that occasionally a sched_yield() call would not result in a wait for the next period edge as expected. It turns out that when we call update_curr_dl() and end up with delta_exec <= 0, we will bail early and fail to throttle. Further inspection of the yield code revealed that yield_task_dl() clearing dl.runtime is wrong too, it will not account the last bit of runtime which could result in dl.runtime < 0, which in turn means that replenish would gift us with too much runtime. Fix both issues by not relying on the dl.runtime value for yield. Reported-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Clark Williams <williams@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160223122822.GP6357@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29sched/cgroup: Fix cgroup entity load tracking tear-downPeter Zijlstra
When a cgroup's CPU runqueue is destroyed, it should remove its remaining load accounting from its parent cgroup. The current site for doing so it unsuited because its far too late and unordered against other cgroup removal (->css_free() will be, but we're also in an RCU callback). Put it in the ->css_offline() callback, which is the start of cgroup destruction, right after the group has been made unavailable to userspace. The ->css_offline() callbacks are called in hierarchical order after the following v4.4 commit: aa226ff4a1ce ("cgroup: make sure a parent css isn't offlined before its children") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160121212416.GL6357@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29perf: Export perf_event_sysfs_show()Thomas Gleixner
Required to use it in modular perf drivers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Harish Chegondi <harish.chegondi@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20160222221012.930735780@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>