linux/kernel/sched/core.c, branch v4.1

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2015-05-22T22:15:30Z

Pull block fixes from Jens Axboe: "Three small fixes that have been picked up the last few weeks. Specifically: - Fix a memory corruption issue in NVMe with malignant user constructed request. From Christoph. - Kill (now) unused blk_queue_bio(), dm was changed to not need this anymore. From Mike Snitzer. - Always use blk_schedule_flush_plug() from the io_schedule() path when flushing a plug, fixing a !TASK_RUNNING warning with md. From Shaohua" * 'for-linus' of git://git.kernel.dk/linux-block: sched: always use blk_schedule_flush_plug in io_schedule_out nvme: fix kernel memory corruption with short INQUIRY buffers block: remove export for blk_queue_bio

sched: always use blk_schedule_flush_plug in io_schedule_out

2015-05-18T22:06:41Z

block plug callback could sleep, so we introduce a parameter 'from_schedule' and corresponding drivers can use it to destinguish a schedule plug flush or a plug finish. Unfortunately io_schedule_out still uses blk_flush_plug(). This causes below output (Note, I added a might_sleep() in raid1_unplug to make it trigger faster, but the whole thing doesn't matter if I add might_sleep). In raid1/10, this can cause deadlock. This patch makes io_schedule_out always uses blk_schedule_flush_plug. This should only impact drivers (as far as I know, raid 1/10) which are sensitive to the 'from_schedule' parameter. [ 370.817949] ------------[ cut here ]------------ [ 370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90() [ 370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [] prepare_to_wait+0x2f/0x90 [ 370.817971] Modules linked in: raid1 [ 370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G W 4.0.0+ #361 [ 370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014 [ 370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1) [ 370.817985] ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001 [ 370.817988] ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8 [ 370.817990] ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28 [ 370.817993] Call Trace: [ 370.817999] [] dump_stack+0x4f/0x7b [ 370.818002] [] warn_slowpath_common+0x8c/0xd0 [ 370.818004] [] warn_slowpath_fmt+0x46/0x50 [ 370.818006] [] ? prepare_to_wait+0x2f/0x90 [ 370.818008] [] ? prepare_to_wait+0x2f/0x90 [ 370.818010] [] __might_sleep+0x7f/0x90 [ 370.818014] [] raid1_unplug+0xd3/0x170 [raid1] [ 370.818024] [] blk_flush_plug_list+0x8a/0x1e0 [ 370.818028] [] ? bit_wait+0x50/0x50 [ 370.818031] [] io_schedule_timeout+0x130/0x140 [ 370.818033] [] bit_wait_io+0x36/0x50 [ 370.818034] [] __wait_on_bit+0x65/0x90 [ 370.818041] [] ? ext4_read_block_bitmap_nowait+0xbc/0x630 [ 370.818043] [] ? bit_wait+0x50/0x50 [ 370.818045] [] out_of_line_wait_on_bit+0x72/0x80 [ 370.818047] [] ? autoremove_wake_function+0x40/0x40 [ 370.818050] [] __wait_on_buffer+0x44/0x50 [ 370.818053] [] ext4_wait_block_bitmap+0xe0/0xf0 [ 370.818058] [] ext4_mb_init_cache+0x206/0x790 [ 370.818062] [] ? lru_cache_add+0x1c/0x50 [ 370.818064] [] ext4_mb_init_group+0x11e/0x200 [ 370.818066] [] ext4_mb_load_buddy+0x341/0x360 [ 370.818068] [] ext4_mb_find_by_goal+0x93/0x2f0 [ 370.818070] [] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818072] [] ext4_mb_regular_allocator+0x67/0x460 [ 370.818074] [] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818076] [] ext4_mb_new_blocks+0x4cb/0x620 [ 370.818079] [] ext4_ext_map_blocks+0x4c6/0x14d0 [ 370.818081] [] ? ext4_es_lookup_extent+0x4e/0x290 [ 370.818085] [] ext4_map_blocks+0x14d/0x4f0 [ 370.818088] [] ext4_writepages+0x76d/0xe50 [ 370.818094] [] do_writepages+0x21/0x50 [ 370.818097] [] __writeback_single_inode+0x60/0x490 [ 370.818099] [] writeback_sb_inodes+0x2da/0x590 [ 370.818103] [] ? trylock_super+0x1b/0x50 [ 370.818105] [] ? trylock_super+0x1b/0x50 [ 370.818107] [] __writeback_inodes_wb+0x9f/0xd0 [ 370.818109] [] wb_writeback+0x34b/0x3c0 [ 370.818111] [] bdi_writeback_workfn+0x23f/0x550 [ 370.818116] [] process_one_work+0x1c8/0x570 [ 370.818117] [] ? process_one_work+0x14b/0x570 [ 370.818119] [] worker_thread+0x11b/0x470 [ 370.818121] [] ? process_one_work+0x570/0x570 [ 370.818124] [] kthread+0xf8/0x110 [ 370.818126] [] ? kthread_create_on_node+0x210/0x210 [ 370.818129] [] ret_from_fork+0x42/0x70 [ 370.818131] [] ? kthread_create_on_node+0x210/0x210 [ 370.818132] ---[ end trace 7b4deb71e68b6605 ]--- V2: don't change ->in_iowait Cc: NeilBrown Signed-off-by: Shaohua Li Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe

sched/core: Fix regression in cpuset_cpu_inactive() for suspend

2015-05-08T09:53:56Z

Commit 3c18d447b3b3 ("sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()"), a SCHED_DEADLINE bugfix, had a logic error that caused a regression in setting a CPU inactive during suspend. I ran into this when a program was failing pthread_setaffinity_np() with EINVAL after a suspend+wake up. A simple reproducer: $ ./a.out sched_setaffinity: Success $ systemctl suspend $ ./a.out sched_setaffinity: Invalid argument ... where ./a.out is: #define _GNU_SOURCE #include #include #include #include #include #include int main(void) { long num_cores; cpu_set_t cpu_set; int ret; num_cores = sysconf(_SC_NPROCESSORS_ONLN); CPU_ZERO(&cpu_set); CPU_SET(num_cores - 1, &cpu_set); errno = 0; ret = sched_setaffinity(getpid(), sizeof(cpu_set), &cpu_set); perror("sched_setaffinity"); return ret ? EXIT_FAILURE : EXIT_SUCCESS; } The mistake is that suspend is handled in the action == CPU_DOWN_PREPARE_FROZEN case of the switch statement in cpuset_cpu_inactive(). However, the commit in question masked out CPU_TASKS_FROZEN from the action, making this case dead. The fix is straightforward. Signed-off-by: Omar Sandoval Signed-off-by: Peter Zijlstra (Intel) Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Juri Lelli Cc: Thomas Gleixner Fixes: 3c18d447b3b3 ("sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()") Link: http://lkml.kernel.org/r/1cb5ecb3d6543c38cce5790387f336f54ec8e2bc.1430733960.git.osandov@osandov.com Signed-off-by: Ingo Molnar

sched: Handle priority boosted tasks proper in setscheduler()

2015-05-08T09:53:55Z

Ronny reported that the following scenario is not handled correctly: T1 (prio = 10) lock(rtmutex); T2 (prio = 20) lock(rtmutex) boost T1 T1 (prio = 20) sys_set_scheduler(prio = 30) T1 prio = 30 .... sys_set_scheduler(prio = 10) T1 prio = 30 The last step is wrong as T1 should now be back at prio 20. Commit c365c292d059 ("sched: Consider pi boosting in setscheduler()") only handles the case where a boosted tasks tries to lower its priority. Fix it by taking the new effective priority into account for the decision whether a change of the priority is required. Reported-by: Ronny Meeus Tested-by: Steven Rostedt Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt Cc: Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Mike Galbraith Fixes: c365c292d059 ("sched: Consider pi boosting in setscheduler()") Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505051806060.4225@nanos Signed-off-by: Ingo Molnar

x86: pvclock: Really remove the sched notifier for cross-cpu migrations

2015-04-27T13:49:30Z

This reverts commits 0a4e6be9ca17c54817cf814b4b5aa60478c6df27 and 80f7fdb1c7f0f9266421f823964fd1962681f6ce. The task migration notifier was originally introduced in order to support the pvclock vsyscall with non-synchronized TSC, but KVM only supports it with synchronized TSC. Hence, on KVM the race condition is only needed due to a bad implementation on the host side, and even then it's so rare that it's mostly theoretical. As far as KVM is concerned it's possible to fix the host, avoiding the additional complexity in the vDSO and the (re)introduction of the task migration notifier. Xen, on the other hand, hasn't yet implemented vsyscall support at all, so we do not care about its plans for non-synchronized TSC. Reported-by: Peter Zijlstra Suggested-by: Marcelo Tosatti Signed-off-by: Paolo Bonzini

Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-04-14T20:58:48Z

Pull NOHZ changes from Ingo Molnar: "This tree adds full dynticks support to KVM guests (support the disabling of the timer tick on the guest). The main missing piece was the recognition of guest execution as RCU extended quiescent state and related changes" * 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kvm,rcu,nohz: use RCU extended quiescent state when running KVM guest context_tracking: Export context_tracking_user_enter/exit context_tracking: Run vtime_user_enter/exit only when state == CONTEXT_USER context_tracking: Add stub context_tracking_is_enabled context_tracking: Generalize context tracking APIs to support user and guest context_tracking: Rename context symbols to prepare for transition state ppc: Remove unused cpp symbols in kvm headers

Merge branch 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2015-04-13T23:47:11Z

Pull cgroup updates from Tejun Heo: "Nothing too interesting. Rik made cpuset cooperate better with isolcpus and there are several other cleanup patches" * 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset, isolcpus: document relationship between cpusets & isolcpus cpusets, isolcpus: exclude isolcpus from load balancing in cpusets sched, isolcpu: make cpu_isolated_map visible outside scheduler cpuset: initialize cpuset a bit early cgroup: Use kvfree in pidlist_free() cgroup: call cgroup_subsys->bind on cgroup subsys initialization

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-04-13T17:47:34Z

Pull scheduler changes from Ingo Molnar: "Major changes: - Reworked CPU capacity code, for better SMP load balancing on systems with assymetric CPUs. (Vincent Guittot, Morten Rasmussen) - Reworked RT task SMP balancing to be push based instead of pull based, to reduce latencies on large CPU count systems. (Steven Rostedt) - SCHED_DEADLINE support updates and fixes. (Juri Lelli) - SCHED_DEADLINE task migration support during CPU hotplug. (Wanpeng Li) - x86 mwait-idle optimizations and fixes. (Mike Galbraith, Len Brown) - sched/numa improvements. (Rik van Riel) - various cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits) sched/core: Drop debugging leftover trace_printk call sched/deadline: Support DL task migration during CPU hotplug sched/core: Check for available DL bandwidth in cpuset_cpu_inactive() sched/deadline: Always enqueue on previous rq when dl_task_timer() fires sched/core: Remove unused argument from init_[rt|dl]_rq() sched/deadline: Fix rt runtime corruption when dl fails its global constraints sched/deadline: Avoid a superfluous check sched: Improve load balancing in the presence of idle CPUs sched: Optimize freq invariant accounting sched: Move CFS tasks to CPUs with higher capacity sched: Add SD_PREFER_SIBLING for SMT level sched: Remove unused struct sched_group_capacity::capacity_orig sched: Replace capacity_factor by usage sched: Calculate CPU's usage statistic and put it into struct sg_lb_stats::group_usage sched: Add struct rq::cpu_capacity_orig sched: Make scale_rt invariant with frequency sched: Make sched entity usage tracking scale-invariant sched: Remove frequency scaling from cpu_capacity sched: Track group sched_entity usage contributions sched: Add sched_avg::utilization_avg_contrib ...

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2015-04-13T16:47:01Z

Pull KVM updates from Paolo Bonzini: "First batch of KVM changes for 4.1 The most interesting bit here is irqfd/ioeventfd support for ARM and ARM64. Summary: ARM/ARM64: fixes for live migration, irqfd and ioeventfd support (enabling vhost, too), page aging s390: interrupt handling rework, allowing to inject all local interrupts via new ioctl and to get/set the full local irq state for migration and introspection. New ioctls to access memory by virtual address, and to get/set the guest storage keys. SIMD support. MIPS: FPU and MIPS SIMD Architecture (MSA) support. Includes some patches from Ralf Baechle's MIPS tree. x86: bugfixes (notably for pvclock, the others are small) and cleanups. Another small latency improvement for the TSC deadline timer" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (146 commits) KVM: use slowpath for cross page cached accesses kvm: mmu: lazy collapse small sptes into large sptes KVM: x86: Clear CR2 on VCPU reset KVM: x86: DR0-DR3 are not clear on reset KVM: x86: BSP in MSR_IA32_APICBASE is writable KVM: x86: simplify kvm_apic_map KVM: x86: avoid logical_map when it is invalid KVM: x86: fix mixed APIC mode broadcast KVM: x86: use MDA for interrupt matching kvm/ppc/mpic: drop unused IRQ_testbit KVM: nVMX: remove unnecessary double caching of MAXPHYADDR KVM: nVMX: checks for address bits beyond MAXPHYADDR on VM-entry KVM: x86: cache maxphyaddr CPUID leaf in struct kvm_vcpu KVM: vmx: pass error code with internal error #2 x86: vdso: fix pvclock races with task migration KVM: remove kvm_read_hva and kvm_read_hva_atomic KVM: x86: optimize delivery of TSC deadline timer interrupt KVM: x86: extract blocking logic from __vcpu_run kvm: x86: fix x86 eflags fixed bit KVM: s390: migrate vcpu interrupt state ...

sched/core: Drop debugging leftover trace_printk call

2015-04-03T08:48:25Z

Commit: 3c18d447b3b3 ("sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()") forgot a trace_printk() debugging piece in and Steve's banner screamed in dmesg. Remove it. Signed-off-by: Borislav Petkov Cc: Juri Lelli Cc: Juri Lelli Cc: Peter Zijlstra (Intel) Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1428050570-21041-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar