| Message ID | 20250218031448.46951-5-inwardvessel@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | cgroup: separate rstat trees | expand |
Hi JP, kernel test robot noticed the following build warnings: [auto build test WARNING on tj-cgroup/for-next] [also build test WARNING on bpf-next/master bpf/master linus/master v6.14-rc3 next-20250219] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/JP-Kobryn/cgroup-move-rstat-pointers-into-struct-of-their-own/20250218-111725 base: https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-next patch link: https://lore.kernel.org/r/20250218031448.46951-5-inwardvessel%40gmail.com patch subject: [PATCH 04/11] cgroup: introduce cgroup_rstat_ops config: arc-randconfig-002-20250219 (https://download.01.org/0day-ci/archive/20250219/202502191558.xCTZRkPs-lkp@intel.com/config) compiler: arc-elf-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250219/202502191558.xCTZRkPs-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202502191558.xCTZRkPs-lkp@intel.com/ All warnings (new ones prefixed by >>): >> kernel/cgroup/rstat.c:210: warning: Function parameter or struct member 'ops' not described in 'cgroup_rstat_push_children' >> kernel/cgroup/rstat.c:269: warning: Function parameter or struct member 'ops' not described in 'cgroup_rstat_updated_list' >> kernel/cgroup/rstat.c:465: warning: Function parameter or struct member 'ops' not described in '__cgroup_rstat_flush_release' kernel/cgroup/rstat.c:465: warning: expecting prototype for cgroup_rstat_flush_release(). Prototype was for __cgroup_rstat_flush_release() instead vim +210 kernel/cgroup/rstat.c 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 194 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 195 /** d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 196 * cgroup_rstat_push_children - push children cgroups into the given list d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 197 * @head: current head of the list (= subtree root) d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 198 * @child: first child of the root 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 199 * @cpu: target cpu d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 200 * Return: A new singly linked list of cgroups to be flush 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 201 * d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 202 * Iteratively traverse down the cgroup_rstat_cpu updated tree level by d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 203 * level and push all the parents first before their next level children d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 204 * into a singly linked list built from the tail backward like "pushing" d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 205 * cgroups into a stack. The root is pushed by the caller. d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 206 */ 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 207 static struct cgroup_rstat *cgroup_rstat_push_children( d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 208 struct cgroup_rstat *head, struct cgroup_rstat *child, int cpu, d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 209 struct cgroup_rstat_ops *ops) d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 @210 { 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 211 struct cgroup_rstat *chead = child; /* Head of child cgroup level */ 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 212 struct cgroup_rstat *ghead = NULL; /* Head of grandchild cgroup level */ 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 213 struct cgroup_rstat *parent, *grandchild; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 214 struct cgroup_rstat_cpu *crstatc; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 215 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 216 child->rstat_flush_next = NULL; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 217 d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 218 next_level: d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 219 while (chead) { d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 220 child = chead; 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 221 chead = child->rstat_flush_next; d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 222 parent = ops->parent_fn(child); d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 223 d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 224 /* updated_next is parent cgroup terminated */ d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 225 while (child != parent) { 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 226 child->rstat_flush_next = head; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 227 head = child; 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 228 crstatc = rstat_cpu(child, cpu); d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 229 grandchild = crstatc->updated_children; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 230 if (grandchild != child) { d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 231 /* Push the grand child to the next level */ d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 232 crstatc->updated_children = child; 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 233 grandchild->rstat_flush_next = ghead; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 234 ghead = grandchild; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 235 } d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 236 child = crstatc->updated_next; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 237 crstatc->updated_next = NULL; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 238 } d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 239 } d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 240 d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 241 if (ghead) { d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 242 chead = ghead; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 243 ghead = NULL; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 244 goto next_level; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 245 } d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 246 return head; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 247 } d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 248 d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 249 /** d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 250 * cgroup_rstat_updated_list - return a list of updated cgroups to be flushed d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 251 * @root: root of the cgroup subtree to traverse d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 252 * @cpu: target cpu d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 253 * Return: A singly linked list of cgroups to be flushed d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 254 * d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 255 * Walks the updated rstat_cpu tree on @cpu from @root. During traversal, d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 256 * each returned cgroup is unlinked from the updated tree. 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 257 * 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 258 * The only ordering guarantee is that, for a parent and a child pair d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 259 * covered by a given traversal, the child is before its parent in d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 260 * the list. d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 261 * d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 262 * Note that updated_children is self terminated and points to a list of d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 263 * child cgroups if not empty. Whereas updated_next is like a sibling link d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 264 * within the children list and terminated by the parent cgroup. An exception d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 265 * here is the cgroup root whose updated_next can be self terminated. 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 266 */ 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 267 static struct cgroup_rstat *cgroup_rstat_updated_list( d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 268 struct cgroup_rstat *root, int cpu, struct cgroup_rstat_ops *ops) 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 @269 { d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 270 raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu); 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 271 struct cgroup_rstat_cpu *rstatc = rstat_cpu(root, cpu); 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 272 struct cgroup_rstat *head = NULL, *parent, *child; d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 273 struct cgroup *cgrp; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 274 unsigned long flags; 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 275 d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 276 cgrp = ops->cgroup_fn(root); 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 277 flags = _cgroup_rstat_cpu_lock(cpu_lock, cpu, cgrp, false); 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 278 d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 279 /* Return NULL if this subtree is not on-list */ d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 280 if (!rstatc->updated_next) d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 281 goto unlock_ret; 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 282 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 283 /* d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 284 * Unlink @root from its parent. As the updated_children list is 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 285 * singly linked, we have to walk it to find the removal point. 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 286 */ d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 287 parent = ops->parent_fn(root); dc26532aed0ab2 kernel/cgroup/rstat.c Johannes Weiner 2021-04-29 288 if (parent) { dc26532aed0ab2 kernel/cgroup/rstat.c Johannes Weiner 2021-04-29 289 struct cgroup_rstat_cpu *prstatc; 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 290 struct cgroup_rstat **nextp; 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 291 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 292 prstatc = rstat_cpu(parent, cpu); c58632b3631cb2 kernel/cgroup/rstat.c Tejun Heo 2018-04-26 293 nextp = &prstatc->updated_children; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 294 while (*nextp != root) { dc26532aed0ab2 kernel/cgroup/rstat.c Johannes Weiner 2021-04-29 295 struct cgroup_rstat_cpu *nrstatc; dc26532aed0ab2 kernel/cgroup/rstat.c Johannes Weiner 2021-04-29 296 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 297 nrstatc = rstat_cpu(*nextp, cpu); 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 298 WARN_ON_ONCE(*nextp == parent); c58632b3631cb2 kernel/cgroup/rstat.c Tejun Heo 2018-04-26 299 nextp = &nrstatc->updated_next; 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 300 } c58632b3631cb2 kernel/cgroup/rstat.c Tejun Heo 2018-04-26 301 *nextp = rstatc->updated_next; dc26532aed0ab2 kernel/cgroup/rstat.c Johannes Weiner 2021-04-29 302 } 9a9e97b2f1f27e kernel/cgroup/rstat.c Tejun Heo 2018-04-26 303 dc26532aed0ab2 kernel/cgroup/rstat.c Johannes Weiner 2021-04-29 304 rstatc->updated_next = NULL; e76d28bdf9ba53 kernel/cgroup/rstat.c Waiman Long 2023-11-03 305 d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 306 /* Push @root to the list first before pushing the children */ d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 307 head = root; 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 308 root->rstat_flush_next = NULL; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 309 child = rstatc->updated_children; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 310 rstatc->updated_children = root; d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 311 if (child != root) d67ed623c585f2 kernel/cgroup/rstat.c JP Kobryn 2025-02-17 312 head = cgroup_rstat_push_children(head, child, cpu, ops); d499fd418fa159 kernel/cgroup/rstat.c Waiman Long 2023-11-30 313 unlock_ret: 3d844899ba042a kernel/cgroup/rstat.c JP Kobryn 2025-02-17 314 _cgroup_rstat_cpu_unlock(cpu_lock, cpu, cgrp, flags, false); e76d28bdf9ba53 kernel/cgroup/rstat.c Waiman Long 2023-11-03 315 return head; 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 316 } 041cd640b2f3c5 kernel/cgroup/stat.c Tejun Heo 2017-09-25 317
On Mon, Feb 17, 2025 at 07:14:41PM -0800, JP Kobryn wrote: > The cgroup_rstat_ops interface provides a way for type-specific > operations to be hidden from the common rstat operations. Use it to > decouple the cgroup_subsys_type from within the internal rstat > updated/flush routines. The new ops interface allows for greater > extensibility in terms of future changes. i.e. public updated/flush Here you might need to be explicit what future changes. Will all controllers using rstat require this ops interface or some of them?
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index a32bcd7942a5..a8bb304e49c4 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -9,6 +9,12 @@ #include <trace/events/cgroup.h> +struct cgroup_rstat_ops { + struct cgroup_rstat *(*parent_fn)(struct cgroup_rstat *); + struct cgroup *(*cgroup_fn)(struct cgroup_rstat *); + void (*flush_fn)(struct cgroup_rstat *, int); +}; + static DEFINE_SPINLOCK(cgroup_rstat_lock); static DEFINE_PER_CPU(raw_spinlock_t, cgroup_rstat_cpu_lock); @@ -19,7 +25,17 @@ static struct cgroup_rstat_cpu *rstat_cpu(struct cgroup_rstat *rstat, int cpu) return per_cpu_ptr(rstat->rstat_cpu, cpu); } -static struct cgroup_rstat *rstat_parent(struct cgroup_rstat *rstat) +static inline bool is_base_css(struct cgroup_subsys_state *css) +{ + /* css for base stats has no subsystem */ + if (!css->ss) + return true; + + return false; +} + +static struct cgroup_rstat *rstat_parent_via_css( + struct cgroup_rstat *rstat) { struct cgroup_subsys_state *css = container_of( rstat, typeof(*css), rstat); @@ -30,6 +46,33 @@ static struct cgroup_rstat *rstat_parent(struct cgroup_rstat *rstat) return &(css->parent->rstat); } +static struct cgroup *rstat_cgroup_via_css(struct cgroup_rstat *rstat) +{ + struct cgroup_subsys_state *css = + container_of(rstat, struct cgroup_subsys_state, rstat); + + return css->cgroup; +} + +static void rstat_flush_via_css(struct cgroup_rstat *rstat, int cpu) +{ + struct cgroup_subsys_state *css = container_of( + rstat, typeof(*css), rstat); + + if (is_base_css(css)) { + cgroup_base_stat_flush(css->cgroup, cpu); + return; + } + + css->ss->css_rstat_flush(css, cpu); +} + +static struct cgroup_rstat_ops rstat_css_ops = { + .parent_fn = rstat_parent_via_css, + .cgroup_fn = rstat_cgroup_via_css, + .flush_fn = rstat_flush_via_css, +}; + /* * Helper functions for rstat per CPU lock (cgroup_rstat_cpu_lock). * @@ -84,11 +127,11 @@ void _cgroup_rstat_cpu_unlock(raw_spinlock_t *cpu_lock, int cpu, raw_spin_unlock_irqrestore(cpu_lock, flags); } -static void __cgroup_rstat_updated(struct cgroup_rstat *rstat, int cpu) +static void __cgroup_rstat_updated(struct cgroup_rstat *rstat, int cpu, + struct cgroup_rstat_ops *ops) { - struct cgroup_subsys_state *css = container_of( - rstat, typeof(*css), rstat); - struct cgroup *cgrp = css->cgroup; + struct cgroup *cgrp; + raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu); unsigned long flags; @@ -103,12 +146,13 @@ static void __cgroup_rstat_updated(struct cgroup_rstat *rstat, int cpu) if (data_race(rstat_cpu(rstat, cpu)->updated_next)) return; + cgrp = ops->cgroup_fn(rstat); flags = _cgroup_rstat_cpu_lock(cpu_lock, cpu, cgrp, true); /* put @rstat and all ancestors on the corresponding updated lists */ while (true) { struct cgroup_rstat_cpu *rstatc = rstat_cpu(rstat, cpu); - struct cgroup_rstat *parent = rstat_parent(rstat); + struct cgroup_rstat *parent = ops->parent_fn(rstat); struct cgroup_rstat_cpu *prstatc; /* @@ -145,7 +189,7 @@ static void __cgroup_rstat_updated(struct cgroup_rstat *rstat, int cpu) */ __bpf_kfunc void cgroup_rstat_updated(struct cgroup_subsys_state *css, int cpu) { - __cgroup_rstat_updated(&css->rstat, cpu); + __cgroup_rstat_updated(&css->rstat, cpu, &rstat_css_ops); } /** @@ -161,7 +205,8 @@ __bpf_kfunc void cgroup_rstat_updated(struct cgroup_subsys_state *css, int cpu) * cgroups into a stack. The root is pushed by the caller. */ static struct cgroup_rstat *cgroup_rstat_push_children( - struct cgroup_rstat *head, struct cgroup_rstat *child, int cpu) + struct cgroup_rstat *head, struct cgroup_rstat *child, int cpu, + struct cgroup_rstat_ops *ops) { struct cgroup_rstat *chead = child; /* Head of child cgroup level */ struct cgroup_rstat *ghead = NULL; /* Head of grandchild cgroup level */ @@ -174,7 +219,7 @@ static struct cgroup_rstat *cgroup_rstat_push_children( while (chead) { child = chead; chead = child->rstat_flush_next; - parent = rstat_parent(child); + parent = ops->parent_fn(child); /* updated_next is parent cgroup terminated */ while (child != parent) { @@ -220,16 +265,15 @@ static struct cgroup_rstat *cgroup_rstat_push_children( * here is the cgroup root whose updated_next can be self terminated. */ static struct cgroup_rstat *cgroup_rstat_updated_list( - struct cgroup_rstat *root, int cpu) + struct cgroup_rstat *root, int cpu, struct cgroup_rstat_ops *ops) { - struct cgroup_subsys_state *css = container_of( - root, typeof(*css), rstat); - struct cgroup *cgrp = css->cgroup; raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu); struct cgroup_rstat_cpu *rstatc = rstat_cpu(root, cpu); struct cgroup_rstat *head = NULL, *parent, *child; + struct cgroup *cgrp; unsigned long flags; + cgrp = ops->cgroup_fn(root); flags = _cgroup_rstat_cpu_lock(cpu_lock, cpu, cgrp, false); /* Return NULL if this subtree is not on-list */ @@ -240,7 +284,7 @@ static struct cgroup_rstat *cgroup_rstat_updated_list( * Unlink @root from its parent. As the updated_children list is * singly linked, we have to walk it to find the removal point. */ - parent = rstat_parent(root); + parent = ops->parent_fn(root); if (parent) { struct cgroup_rstat_cpu *prstatc; struct cgroup_rstat **nextp; @@ -265,7 +309,7 @@ static struct cgroup_rstat *cgroup_rstat_updated_list( child = rstatc->updated_children; rstatc->updated_children = root; if (child != root) - head = cgroup_rstat_push_children(head, child, cpu); + head = cgroup_rstat_push_children(head, child, cpu, ops); unlock_ret: _cgroup_rstat_cpu_unlock(cpu_lock, cpu, cgrp, flags, false); return head; @@ -323,34 +367,30 @@ static inline void __cgroup_rstat_unlock(struct cgroup *cgrp, int cpu_in_loop) } /* see cgroup_rstat_flush() */ -static void cgroup_rstat_flush_locked(struct cgroup_rstat *rstat) +static void cgroup_rstat_flush_locked(struct cgroup_rstat *rstat, + struct cgroup_rstat_ops *ops) __releases(&cgroup_rstat_lock) __acquires(&cgroup_rstat_lock) { - struct cgroup_subsys_state *css = container_of( - rstat, typeof(*css), rstat); - struct cgroup *cgrp = css->cgroup; int cpu; lockdep_assert_held(&cgroup_rstat_lock); for_each_possible_cpu(cpu) { - struct cgroup_rstat *pos = cgroup_rstat_updated_list(rstat, cpu); + struct cgroup_rstat *pos = cgroup_rstat_updated_list( + rstat, cpu, ops); for (; pos; pos = pos->rstat_flush_next) { - struct cgroup_subsys_state *pos_css = container_of( - pos, typeof(*pos_css), rstat); - struct cgroup *pos_cgroup = pos_css->cgroup; - - if (!pos_css->ss) - cgroup_base_stat_flush(pos_cgroup, cpu); - else - pos_css->ss->css_rstat_flush(pos_css, cpu); + struct cgroup *pos_cgroup = ops->cgroup_fn(pos); + ops->flush_fn(pos, cpu); bpf_rstat_flush(pos_cgroup, cgroup_parent(pos_cgroup), cpu); } /* play nice and yield if necessary */ if (need_resched() || spin_needbreak(&cgroup_rstat_lock)) { + struct cgroup *cgrp; + + cgrp = ops->cgroup_fn(rstat); __cgroup_rstat_unlock(cgrp, cpu); if (!cond_resched()) cpu_relax(); @@ -359,16 +399,15 @@ static void cgroup_rstat_flush_locked(struct cgroup_rstat *rstat) } } -static void __cgroup_rstat_flush(struct cgroup_rstat *rstat) +static void __cgroup_rstat_flush(struct cgroup_rstat *rstat, + struct cgroup_rstat_ops *ops) { - struct cgroup_subsys_state *css = container_of( - rstat, typeof(*css), rstat); - struct cgroup *cgrp = css->cgroup; + struct cgroup *cgrp; might_sleep(); - + cgrp = ops->cgroup_fn(rstat); __cgroup_rstat_lock(cgrp, -1); - cgroup_rstat_flush_locked(rstat); + cgroup_rstat_flush_locked(rstat, ops); __cgroup_rstat_unlock(cgrp, -1); } @@ -387,19 +426,19 @@ static void __cgroup_rstat_flush(struct cgroup_rstat *rstat) */ __bpf_kfunc void cgroup_rstat_flush(struct cgroup_subsys_state *css) { - __cgroup_rstat_flush(&css->rstat); + __cgroup_rstat_flush(&css->rstat, &rstat_css_ops); } -static void __cgroup_rstat_flush_hold(struct cgroup_rstat *rstat) +static void __cgroup_rstat_flush_hold(struct cgroup_rstat *rstat, + struct cgroup_rstat_ops *ops) __acquires(&cgroup_rstat_lock) { - struct cgroup_subsys_state *css = container_of( - rstat, typeof(*css), rstat); - struct cgroup *cgrp = css->cgroup; + struct cgroup *cgrp; might_sleep(); + cgrp = ops->cgroup_fn(rstat); __cgroup_rstat_lock(cgrp, -1); - cgroup_rstat_flush_locked(rstat); + cgroup_rstat_flush_locked(rstat, ops); } /** @@ -413,20 +452,20 @@ static void __cgroup_rstat_flush_hold(struct cgroup_rstat *rstat) */ void cgroup_rstat_flush_hold(struct cgroup_subsys_state *css) { - __cgroup_rstat_flush_hold(&css->rstat); + __cgroup_rstat_flush_hold(&css->rstat, &rstat_css_ops); } /** * cgroup_rstat_flush_release - release cgroup_rstat_flush_hold() * @rstat: rstat node used to find associated cgroup used by tracepoint */ -static void __cgroup_rstat_flush_release(struct cgroup_rstat *rstat) +static void __cgroup_rstat_flush_release(struct cgroup_rstat *rstat, + struct cgroup_rstat_ops *ops) __releases(&cgroup_rstat_lock) { - struct cgroup_subsys_state *css = container_of( - rstat, typeof(*css), rstat); - struct cgroup *cgrp = css->cgroup; + struct cgroup *cgrp; + cgrp = ops->cgroup_fn(rstat); __cgroup_rstat_unlock(cgrp, -1); } @@ -436,7 +475,7 @@ static void __cgroup_rstat_flush_release(struct cgroup_rstat *rstat) */ void cgroup_rstat_flush_release(struct cgroup_subsys_state *css) { - __cgroup_rstat_flush_release(&css->rstat); + __cgroup_rstat_flush_release(&css->rstat, &rstat_css_ops); } static void __cgroup_rstat_init(struct cgroup_rstat *rstat)
The cgroup_rstat_ops interface provides a way for type-specific operations to be hidden from the common rstat operations. Use it to decouple the cgroup_subsys_type from within the internal rstat updated/flush routines. The new ops interface allows for greater extensibility in terms of future changes. i.e. public updated/flush api's can be created that accept a arbitrary types, as long as that type has an associated ops interface. Signed-off-by: JP Kobryn <inwardvessel@gmail.com> --- kernel/cgroup/rstat.c | 131 +++++++++++++++++++++++++++--------------- 1 file changed, 85 insertions(+), 46 deletions(-)