From c149c4a48b19afbf0c383614e57b452d39b154de Mon Sep 17 00:00:00 2001 From: Xiu Jianfeng Date: Sat, 13 Jul 2024 08:59:16 +0000 Subject: cgroup/cpuset: Remove cpuset_slab_spread_rotor Since the SLAB implementation was removed in v6.8, so the cpuset_slab_spread_rotor is no longer used and can be removed. Signed-off-by: Xiu Jianfeng Reviewed-by: Waiman Long Signed-off-by: Tejun Heo --- include/linux/cpuset.h | 6 ------ include/linux/sched.h | 1 - 2 files changed, 7 deletions(-) (limited to 'include') diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index de4cf0ee96f7..2a6981eeebf8 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -113,7 +113,6 @@ extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *tsk); extern int cpuset_mem_spread_node(void); -extern int cpuset_slab_spread_node(void); static inline int cpuset_do_page_mem_spread(void) { @@ -246,11 +245,6 @@ static inline int cpuset_mem_spread_node(void) return 0; } -static inline int cpuset_slab_spread_node(void) -{ - return 0; -} - static inline int cpuset_do_page_mem_spread(void) { return 0; diff --git a/include/linux/sched.h b/include/linux/sched.h index f8d150343d42..3773c1c8f099 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1243,7 +1243,6 @@ struct task_struct { /* Sequence number to catch updates: */ seqcount_spinlock_t mems_allowed_seq; int cpuset_mem_spread_rotor; - int cpuset_slab_spread_rotor; #endif #ifdef CONFIG_CGROUPS /* Control Group info protected by css_set_lock: */ -- cgit v1.2.3 From 93c8332c8373fee415bd79f08d5ba4ba7ca5ad15 Mon Sep 17 00:00:00 2001 From: Xavier Date: Thu, 4 Jul 2024 14:24:43 +0800 Subject: Union-Find: add a new module in kernel library This patch implements a union-find data structure in the kernel library, which includes operations for allocating nodes, freeing nodes, finding the root of a node, and merging two nodes. Signed-off-by: Xavier Signed-off-by: Tejun Heo --- include/linux/union_find.h | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 include/linux/union_find.h (limited to 'include') diff --git a/include/linux/union_find.h b/include/linux/union_find.h new file mode 100644 index 000000000000..cfd49263c138 --- /dev/null +++ b/include/linux/union_find.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_UNION_FIND_H +#define __LINUX_UNION_FIND_H +/** + * union_find.h - union-find data structure implementation + * + * This header provides functions and structures to implement the union-find + * data structure. The union-find data structure is used to manage disjoint + * sets and supports efficient union and find operations. + * + * See Documentation/core-api/union_find.rst for documentation and samples. + */ + +struct uf_node { + struct uf_node *parent; + unsigned int rank; +}; + +/* This macro is used for static initialization of a union-find node. */ +#define UF_INIT_NODE(node) {.parent = &node, .rank = 0} + +/** + * uf_node_init - Initialize a union-find node + * @node: pointer to the union-find node to be initialized + * + * This function sets the parent of the node to itself and + * initializes its rank to 0. + */ +static inline void uf_node_init(struct uf_node *node) +{ + node->parent = node; + node->rank = 0; +} + +/* find the root of a node */ +struct uf_node *uf_find(struct uf_node *node); + +/* Merge two intersecting nodes */ +void uf_union(struct uf_node *node1, struct uf_node *node2); + +#endif /* __LINUX_UNION_FIND_H */ -- cgit v1.2.3 From ab03125268679e058e1e7b6612f6d12610761769 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Mon, 15 Jul 2024 11:00:34 -0400 Subject: cgroup: Show # of subsystem CSSes in cgroup.stat MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cgroup subsystem state (CSS) is an abstraction in the cgroup layer to help manage different structures in various cgroup subsystems by being an embedded element inside a larger structure like cpuset or mem_cgroup. The /proc/cgroups file shows the number of cgroups for each of the subsystems. With cgroup v1, the number of CSSes is the same as the number of cgroups. That is not the case anymore with cgroup v2. The /proc/cgroups file cannot show the actual number of CSSes for the subsystems that are bound to cgroup v2. So if a v2 cgroup subsystem is leaking cgroups (usually memory cgroup), we can't tell by looking at /proc/cgroups which cgroup subsystems may be responsible. As cgroup v2 had deprecated the use of /proc/cgroups, the hierarchical cgroup.stat file is now being extended to show the number of live and dying CSSes associated with all the non-inhibited cgroup subsystems that have been bound to cgroup v2. The number includes CSSes in the current cgroup as well as in all the descendants underneath it. This will help us pinpoint which subsystems are responsible for the increasing number of dying (nr_dying_descendants) cgroups. The CSSes dying counts are stored in the cgroup structure itself instead of inside the CSS as suggested by Johannes. This will allow us to accurately track dying counts of cgroup subsystems that have recently been disabled in a cgroup. It is now possible that a zero subsystem number is coupled with a non-zero dying subsystem number. The cgroup-v2.rst file is updated to discuss this new behavior. With this patch applied, a sample output from root cgroup.stat file was shown below. nr_descendants 56 nr_subsys_cpuset 1 nr_subsys_cpu 43 nr_subsys_io 43 nr_subsys_memory 56 nr_subsys_perf_event 57 nr_subsys_hugetlb 1 nr_subsys_pids 56 nr_subsys_rdma 1 nr_subsys_misc 1 nr_dying_descendants 30 nr_dying_subsys_cpuset 0 nr_dying_subsys_cpu 0 nr_dying_subsys_io 0 nr_dying_subsys_memory 30 nr_dying_subsys_perf_event 0 nr_dying_subsys_hugetlb 0 nr_dying_subsys_pids 0 nr_dying_subsys_rdma 0 nr_dying_subsys_misc 0 Another sample output from system.slice/cgroup.stat was: nr_descendants 34 nr_subsys_cpuset 0 nr_subsys_cpu 32 nr_subsys_io 32 nr_subsys_memory 34 nr_subsys_perf_event 35 nr_subsys_hugetlb 0 nr_subsys_pids 34 nr_subsys_rdma 0 nr_subsys_misc 0 nr_dying_descendants 30 nr_dying_subsys_cpuset 0 nr_dying_subsys_cpu 0 nr_dying_subsys_io 0 nr_dying_subsys_memory 30 nr_dying_subsys_perf_event 0 nr_dying_subsys_hugetlb 0 nr_dying_subsys_pids 0 nr_dying_subsys_rdma 0 nr_dying_subsys_misc 0 Note that 'debug' controller wasn't used to provide this information because the controller is not recommended in productions kernels, also many of them won't enable CONFIG_CGROUP_DEBUG by default. Similar information could be retrieved with debuggers like drgn but that's also not always available (e.g. lockdown) and the additional cost of runtime tracking here is deemed marginal. tj: Added Michal's paragraphs on why this is not added the debug controller to the commit message. Signed-off-by: Waiman Long Acked-by: Johannes Weiner Acked-by: Roman Gushchin Reviewed-by: Kamalesh Babulal Cc: Michal Koutný Link: http://lkml.kernel.org/r/20240715150034.2583772-1-longman@redhat.com Signed-off-by: Tejun Heo --- include/linux/cgroup-defs.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include') diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index ae04035b6cbe..eb0f6f349496 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -210,6 +210,14 @@ struct cgroup_subsys_state { * fields of the containing structure. */ struct cgroup_subsys_state *parent; + + /* + * Keep track of total numbers of visible descendant CSSes. + * The total number of dying CSSes is tracked in + * css->cgroup->nr_dying_subsys[ssid]. + * Protected by cgroup_mutex. + */ + int nr_descendants; }; /* @@ -470,6 +478,12 @@ struct cgroup { /* Private pointers for each registered subsystem */ struct cgroup_subsys_state __rcu *subsys[CGROUP_SUBSYS_COUNT]; + /* + * Keep track of total number of dying CSSes at and below this cgroup. + * Protected by cgroup_mutex. + */ + int nr_dying_subsys[CGROUP_SUBSYS_COUNT]; + struct cgroup_root *root; /* -- cgit v1.2.3 From 1abab1ba0775036bb67c6c57945c637be644c04f Mon Sep 17 00:00:00 2001 From: Chen Ridong Date: Fri, 30 Aug 2024 10:02:28 +0000 Subject: cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1 This patch introduces CONFIG_CPUSETS_V1 and guard cpuset-v1 code under CONFIG_CPUSETS_V1. The default value of CONFIG_CPUSETS_V1 is N, so that user who adopted v2 don't have 'pay' for cpuset v1. Signed-off-by: Chen Ridong Acked-by: Waiman Long Signed-off-by: Tejun Heo --- include/linux/cpuset.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index 2a6981eeebf8..835e7b793f6a 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -99,6 +99,7 @@ static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask) extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, const struct task_struct *tsk2); +#ifdef CONFIG_CPUSETS_V1 #define cpuset_memory_pressure_bump() \ do { \ if (cpuset_memory_pressure_enabled) \ @@ -106,6 +107,9 @@ extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, } while (0) extern int cpuset_memory_pressure_enabled; extern void __cpuset_memory_pressure_bump(void); +#else +static inline void cpuset_memory_pressure_bump(void) { } +#endif extern void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task); -- cgit v1.2.3