linux/kernel/cgroup, branch v5.4

Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2019-11-15T16:44:08Z

Pull misc vfs fixes from Al Viro: "Assorted fixes all over the place; some of that is -stable fodder, some regressions from the last window" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ecryptfs_lookup_interpose(): lower_dentry->d_parent is not stable either ecryptfs_lookup_interpose(): lower_dentry->d_inode is not stable ecryptfs: fix unlink and rmdir in face of underlying fs modifications audit_get_nd(): don't unlock parent too early exportfs_decode_fh(): negative pinned may become positive without the parent locked cgroup: don't put ERR_PTR() into fc->root autofs: fix a leak in autofs_expire_indirect() aio: Fix io_pgetevents() struct __compat_aio_sigset layout fs/namespace.c: fix use-after-free of mount in mnt_warn_timestamp_expiry()

cgroup: don't put ERR_PTR() into fc->root

2019-11-10T16:53:27Z

the caller of ->get_tree() expects NULL left there on error... Reported-by: Thibaut Sautereau Signed-off-by: Al Viro

sched/topology: Don't try to build empty sched domains

2019-10-29T08:58:45Z

Turns out hotplugging CPUs that are in exclusive cpusets can lead to the cpuset code feeding empty cpumasks to the sched domain rebuild machinery. This leads to the following splat: Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 235 Comm: kworker/5:2 Not tainted 5.4.0-rc1-00005-g8d495477d62e #23 Hardware name: ARM Juno development board (r0) (DT) Workqueue: events cpuset_hotplug_workfn pstate: 60000005 (nZCv daif -PAN -UAO) pc : build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969) lr : build_sched_domains (kernel/sched/topology.c:1966) Call trace: build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969) partition_sched_domains_locked (kernel/sched/topology.c:2250) rebuild_sched_domains_locked (./include/linux/bitmap.h:370 ./include/linux/cpumask.h:538 kernel/cgroup/cpuset.c:955 kernel/cgroup/cpuset.c:978 kernel/cgroup/cpuset.c:1019) rebuild_sched_domains (kernel/cgroup/cpuset.c:1032) cpuset_hotplug_workfn (kernel/cgroup/cpuset.c:3205 (discriminator 2)) process_one_work (./arch/arm64/include/asm/jump_label.h:21 ./include/linux/jump_label.h:200 ./include/trace/events/workqueue.h:114 kernel/workqueue.c:2274) worker_thread (./include/linux/compiler.h:199 ./include/linux/list.h:268 kernel/workqueue.c:2416) kthread (kernel/kthread.c:255) ret_from_fork (arch/arm64/kernel/entry.S:1167) Code: f860dae2 912802d6 aa1603e1 12800000 (f8616853) The faulty line in question is: cap = arch_scale_cpu_capacity(cpumask_first(cpu_map)); and we're not checking the return value against nr_cpu_ids (we shouldn't have to!), which leads to the above. Prevent generate_sched_domains() from returning empty cpumasks, and add some assertion in build_sched_domains() to scream bloody murder if it happens again. The above splat was obtained on my Juno r0 with the following reproducer: $ cgcreate -g cpuset:asym $ cgset -r cpuset.cpus=0-3 asym $ cgset -r cpuset.mems=0 asym $ cgset -r cpuset.cpu_exclusive=1 asym $ cgcreate -g cpuset:smp $ cgset -r cpuset.cpus=4-5 smp $ cgset -r cpuset.mems=0 smp $ cgset -r cpuset.cpu_exclusive=1 smp $ cgset -r cpuset.sched_load_balance=0 . $ echo 0 > /sys/devices/system/cpu/cpu4/online $ echo 0 > /sys/devices/system/cpu/cpu5/online Signed-off-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Cc: Dietmar.Eggemann@arm.com Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: hannes@cmpxchg.org Cc: lizefan@huawei.com Cc: morten.rasmussen@arm.com Cc: qperret@google.com Cc: tj@kernel.org Cc: vincent.guittot@linaro.org Fixes: 05484e098448 ("sched/topology: Add SD_ASYM_CPUCAPACITY flag detection") Link: https://lkml.kernel.org/r/20191023153745.19515-2-valentin.schneider@arm.com Signed-off-by: Ingo Molnar

Merge branch 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2019-09-17T22:57:22Z

Pull cgroup updates from Tejun Heo: "Three minor cleanup patches" * 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Use kvmalloc in cgroups-v1 cgroup: minor tweak for logic to get cgroup css cgroup: Replace a seq_printf() call by seq_puts() in cgroup_print_ss_mask()

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

2019-09-17T00:25:49Z

Pull scheduler updates from Ingo Molnar: - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann, Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers. As perf and the scheduler is getting bigger and more complex, document the status quo of current responsibilities and interests, and spread the review pain^H^H^H^H fun via an increase in the Cc: linecount generated by scripts/get_maintainer.pl. :-) - Add another series of patches that brings the -rt (PREEMPT_RT) tree closer to mainline: split the monolithic CONFIG_PREEMPT dependencies into a new CONFIG_PREEMPTION category that will allow the eventual introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches to go though. - Extend the CPU cgroup controller with uclamp.min and uclamp.max to allow the finer shaping of CPU bandwidth usage. - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS). - Improve the behavior of high CPU count, high thread count applications running under cpu.cfs_quota_us constraints. - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present. - Improve CPU isolation housekeeping CPU allocation NUMA locality. - Fix deadline scheduler bandwidth calculations and logic when cpusets rebuilds the topology, or when it gets deadline-throttled while it's being offlined. - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from setscheduler() system calls without creating global serialization. Add new synchronization between cpuset topology-changing events and the deadline acceptance tests in setscheduler(), which were broken before. - Rework the active_mm state machine to be less confusing and more optimal. - Rework (simplify) the pick_next_task() slowpath. - Improve load-balancing on AMD EPYC systems. - ... and misc cleanups, smaller fixes and improvements - please see the Git log for more details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) sched/psi: Correct overly pessimistic size calculation sched/fair: Speed-up energy-aware wake-ups sched/uclamp: Always use 'enum uclamp_id' for clamp_id values sched/uclamp: Update CPU's refcount on TG's clamp changes sched/uclamp: Use TG's clamps to restrict TASK's clamps sched/uclamp: Propagate system defaults to the root group sched/uclamp: Propagate parent clamps sched/uclamp: Extend CPU's cgroup controller sched/topology: Improve load balancing on AMD EPYC systems arch, ia64: Make NUMA select SMP sched, perf: MAINTAINERS update, add submaintainers and reviewers sched/fair: Use rq_lock/unlock in online_fair_sched_group cpufreq: schedutil: fix equation in comment sched: Rework pick_next_task() slow-path sched: Allow put_prev_task() to drop rq->lock sched/fair: Expose newidle_balance() sched: Add task_struct pointer to sched_class::set_curr_task sched: Rework CPU hotplug task selection sched/{rt,deadline}: Fix set_next_task vs pick_next_task sched: Fix kerneldoc comment for ia64_set_curr_task ...

cgroup: freezer: fix frozen state inheritance

2019-09-12T21:04:45Z

If a new child cgroup is created in the frozen cgroup hierarchy (one or more of ancestor cgroups is frozen), the CGRP_FREEZE cgroup flag should be set. Otherwise if a process will be attached to the child cgroup, it won't become frozen. The problem can be reproduced with the test_cgfreezer_mkdir test. This is the output before this patch: ~/test_freezer ok 1 test_cgfreezer_simple ok 2 test_cgfreezer_tree ok 3 test_cgfreezer_forkbomb Cgroup /sys/fs/cgroup/cg_test_mkdir_A/cg_test_mkdir_B isn't frozen not ok 4 test_cgfreezer_mkdir ok 5 test_cgfreezer_rmdir ok 6 test_cgfreezer_migrate ok 7 test_cgfreezer_ptrace ok 8 test_cgfreezer_stopped ok 9 test_cgfreezer_ptraced ok 10 test_cgfreezer_vfork And with this patch: ~/test_freezer ok 1 test_cgfreezer_simple ok 2 test_cgfreezer_tree ok 3 test_cgfreezer_forkbomb ok 4 test_cgfreezer_mkdir ok 5 test_cgfreezer_rmdir ok 6 test_cgfreezer_migrate ok 7 test_cgfreezer_ptrace ok 8 test_cgfreezer_stopped ok 9 test_cgfreezer_ptraced ok 10 test_cgfreezer_vfork Reported-by: Mark Crossen Signed-off-by: Roman Gushchin Fixes: 76f969e8948d ("cgroup: cgroup v2 freezer") Cc: Tejun Heo Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Tejun Heo

Use kvmalloc in cgroups-v1

2019-08-07T18:37:58Z

Instead of using its own logic for k-/vmalloc rely on kvmalloc which is actually doing quite the same. Signed-off-by: Marc Koderer Signed-off-by: Tejun Heo

sched/core: Prevent race condition between cpuset and __sched_setscheduler()

2019-07-25T13:55:04Z

No synchronisation mechanism exists between the cpuset subsystem and calls to function __sched_setscheduler(). As such, it is possible that new root domains are created on the cpuset side while a deadline acceptance test is carried out in __sched_setscheduler(), leading to a potential oversell of CPU bandwidth. Grab cpuset_rwsem read lock from core scheduler, so to prevent situations such as the one described above from happening. The only exception is normalize_rt_tasks() which needs to work under tasklist_lock and can't therefore grab cpuset_rwsem. We are fine with this, as this function is only called by sysrq and, if that gets triggered, DEADLINE guarantees are already gone out of the window anyway. Tested-by: Dietmar Eggemann Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: lizefan@huawei.com Cc: longman@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: rostedt@goodmis.org Cc: tj@kernel.org Cc: tommaso.cucinotta@santannapisa.it Link: https://lkml.kernel.org/r/20190719140000.31694-9-juri.lelli@redhat.com Signed-off-by: Ingo Molnar

cgroup/cpuset: Change cpuset_rwsem and hotplug lock order

2019-07-25T13:55:03Z

cpuset_rwsem is going to be acquired from sched_setscheduler() with a following patch. There are however paths (e.g., spawn_ksoftirqd) in which sched_scheduler() is eventually called while holding hotplug lock; this creates a dependecy between hotplug lock (to be always acquired first) and cpuset_rwsem (to be always acquired after hotplug lock). Fix paths which currently take the two locks in the wrong order (after a following patch is applied). Tested-by: Dietmar Eggemann Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: lizefan@huawei.com Cc: longman@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: rostedt@goodmis.org Cc: tj@kernel.org Cc: tommaso.cucinotta@santannapisa.it Link: https://lkml.kernel.org/r/20190719140000.31694-7-juri.lelli@redhat.com Signed-off-by: Ingo Molnar

cgroup/cpuset: Convert cpuset_mutex to percpu_rwsem

2019-07-25T13:55:02Z

Holding cpuset_mutex means that cpusets are stable (only the holder can make changes) and this is required for fixing a synchronization issue between cpusets and scheduler core. However, grabbing cpuset_mutex from setscheduler() hotpath (as implemented in a later patch) is a no-go, as it would create a bottleneck for tasks concurrently calling setscheduler(). Convert cpuset_mutex to be a percpu_rwsem (cpuset_rwsem), so that setscheduler() will then be able to read lock it and avoid concurrency issues. Tested-by: Dietmar Eggemann Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: lizefan@huawei.com Cc: longman@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: rostedt@goodmis.org Cc: tj@kernel.org Cc: tommaso.cucinotta@santannapisa.it Link: https://lkml.kernel.org/r/20190719140000.31694-6-juri.lelli@redhat.com Signed-off-by: Ingo Molnar