user/sven/linux.git/kernel/cgroup, branch v5.5-rc2

Merge branch 'for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2019-11-26T03:23:46Z

Pull cgroup updates from Tejun Heo: "There are several notable changes here: - Single thread migrating itself has been optimized so that it doesn't need threadgroup rwsem anymore. - Freezer optimization to avoid unnecessary frozen state changes. - cgroup ID unification so that cgroup fs ino is the only unique ID used for the cgroup and can be used to directly look up live cgroups through filehandle interface on 64bit ino archs. On 32bit archs, cgroup fs ino is still the only ID in use but it is only unique when combined with gen. - selftest and other changes" * 'for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (24 commits) writeback: fix -Wformat compilation warnings docs: cgroup: mm: Fix spelling of "list" cgroup: fix incorrect WARN_ON_ONCE() in cgroup_setup_root() cgroup: use cgrp->kn->id as the cgroup ID kernfs: use 64bit inos if ino_t is 64bit kernfs: implement custom exportfs ops and fid type kernfs: combine ino/id lookup functions into kernfs_find_and_get_node_by_id() kernfs: convert kernfs_node->id from union kernfs_node_id to u64 kernfs: kernfs_find_and_get_node_by_ino() should only look up activated nodes kernfs: use dumber locking for kernfs_find_and_get_node_by_ino() netprio: use css ID instead of cgroup ID writeback: use ino_t for inodes in tracepoints kernfs: fix ino wrap-around detection kselftests: cgroup: Avoid the reuse of fd after it is deallocated cgroup: freezer: don't change task and cgroups status unnecessarily cgroup: use cgroup->last_bstat instead of cgroup->bstat_pending for consistency cgroup: remove cgroup_enable_task_cg_lists() optimization cgroup: pids: use atomic64_t for pids->limit selftests: cgroup: Run test_core under interfering stress selftests: cgroup: Add task migration tests ...

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: fix incorrect WARN_ON_ONCE() in cgroup_setup_root()

2019-11-14T22:46:51Z

743210386c03 ("cgroup: use cgrp->kn->id as the cgroup ID") added WARN which triggers if cgroup_id(root_cgrp) is not 1. This is fine on 64bit ino archs but on 32bit archs cgroup ID is ((gen << 32) | ino) and gen starts at 1, so the root id is 0x1_0000_0001 instead of 1 always triggering the WARN. What we wanna make sure is that the ino part is 1. Fix it. Reported-by: Naresh Kamboju Fixes: 743210386c03 ("cgroup: use cgrp->kn->id as the cgroup ID") Signed-off-by: Tejun Heo

cgroup: use cgrp->kn->id as the cgroup ID

2019-11-12T16:18:04Z

cgroup ID is currently allocated using a dedicated per-hierarchy idr and used internally and exposed through tracepoints and bpf. This is confusing because there are tracepoints and other interfaces which use the cgroupfs ino as IDs. The preceding changes made kn->id exposed as ino as 64bit ino on supported archs or ino+gen (low 32bits as ino, high gen). There's no reason for cgroup to use different IDs. The kernfs IDs are unique and userland can easily discover them and map them back to paths using standard file operations. This patch replaces cgroup IDs with kernfs IDs. * cgroup_id() is added and all cgroup ID users are converted to use it. * kernfs_node creation is moved to earlier during cgroup init so that cgroup_id() is available during init. * While at it, s/cgroup/cgrp/ in psi helpers for consistency. * Fallback ID value is changed to 1 to be consistent with root cgroup ID. Signed-off-by: Tejun Heo Reviewed-by: Greg Kroah-Hartman Cc: Namhyung Kim

kernfs: combine ino/id lookup functions into kernfs_find_and_get_node_by_id()

2019-11-12T16:18:04Z

kernfs_find_and_get_node_by_ino() looks the kernfs_node matching the specified ino. On top of that, kernfs_get_node_by_id() and kernfs_fh_get_inode() implement full ID matching by testing the rest of ID. On surface, confusingly, the two are slightly different in that the latter uses 0 gen as wildcard while the former doesn't - does it mean that the latter can't uniquely identify inodes w/ 0 gen? In practice, this is a distinction without a difference because generation number starts at 1. There are no actual IDs with 0 gen, so it can always safely used as wildcard. Let's simplify the code by renaming kernfs_find_and_get_node_by_ino() to kernfs_find_and_get_node_by_id(), moving all lookup logics into it, and removing now unnecessary kernfs_get_node_by_id(). Signed-off-by: Tejun Heo Reviewed-by: Greg Kroah-Hartman

kernfs: convert kernfs_node->id from union kernfs_node_id to u64

2019-11-12T16:18:03Z

kernfs_node->id is currently a union kernfs_node_id which represents either a 32bit (ino, gen) pair or u64 value. I can't see much value in the usage of the union - all that's needed is a 64bit ID which the current code is already limited to. Using a union makes the code unnecessarily complicated and prevents using 64bit ino without adding practical benefits. This patch drops union kernfs_node_id and makes kernfs_node->id a u64. ino is stored in the lower 32bits and gen upper. Accessors - kernfs[_id]_ino() and kernfs[_id]_gen() - are added to retrieve the ino and gen. This simplifies ID handling less cumbersome and will allow using 64bit inos on supported archs. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo Reviewed-by: Greg Kroah-Hartman Cc: Namhyung Kim Cc: Jens Axboe Cc: Alexei Starovoitov

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

cgroup: freezer: don't change task and cgroups status unnecessarily

2019-11-07T15:38:41Z

It's not necessary to adjust the task state and revisit the state of source and destination cgroups if the cgroups are not in freeze state and the task itself is not frozen. And in this scenario, it wakes up the task who's not supposed to be ready to run. Don't do the unnecessary task state adjustment can help stop waking up the task without a reason. Signed-off-by: Honglei Wang Acked-by: Roman Gushchin Signed-off-by: Tejun Heo

cgroup: use cgroup->last_bstat instead of cgroup->bstat_pending for consistency

2019-11-06T20:50:15Z

cgroup->bstat_pending is used to determine the base stat delta to propagate to the parent. While correct, this is different from how percpu delta is determined for no good reason and the inconsistency makes the code more difficult to understand. This patch makes parent propagation delta calculation use the same method as percpu to global propagation. * cgroup_base_stat_accumulate() is renamed to cgroup_base_stat_add() and cgroup_base_stat_sub() is added. * percpu propagation calculation is updated to use the above helpers. * cgroup->bstat_pending is replaced with cgroup->last_bstat and updated to use the same calculation as percpu propagation. Signed-off-by: Tejun Heo

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