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Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/…
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…git/tj/cgroup.git
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@sfrothwell
sfrothwell committed Jun 21, 2022
2 parents b9eb320 + 507c869 commit 4992762
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Showing 4 changed files with 71 additions and 58 deletions.
5 changes: 3 additions & 2 deletions include/linux/cgroup-defs.h
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Original file line number Diff line number Diff line change
Expand Up @@ -264,7 +264,8 @@ struct css_set {
* List of csets participating in the on-going migration either as
* source or destination. Protected by cgroup_mutex.
*/
struct list_head mg_preload_node;
struct list_head mg_src_preload_node;
struct list_head mg_dst_preload_node;
struct list_head mg_node;

/*
Expand Down Expand Up @@ -475,7 +476,7 @@ struct cgroup {
struct work_struct release_agent_work;

/* used to track pressure stalls */
struct psi_group psi;
struct psi_group *psi;

/* used to store eBPF programs */
struct cgroup_bpf bpf;
Expand Down
2 changes: 1 addition & 1 deletion include/linux/cgroup.h
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Original file line number Diff line number Diff line change
Expand Up @@ -674,7 +674,7 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp)

static inline struct psi_group *cgroup_psi(struct cgroup *cgrp)
{
return &cgrp->psi;
return cgrp->psi;
}

bool cgroup_psi_enabled(void);
Expand Down
103 changes: 54 additions & 49 deletions kernel/cgroup/cgroup.c
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Original file line number Diff line number Diff line change
Expand Up @@ -765,7 +765,8 @@ struct css_set init_css_set = {
.task_iters = LIST_HEAD_INIT(init_css_set.task_iters),
.threaded_csets = LIST_HEAD_INIT(init_css_set.threaded_csets),
.cgrp_links = LIST_HEAD_INIT(init_css_set.cgrp_links),
.mg_preload_node = LIST_HEAD_INIT(init_css_set.mg_preload_node),
.mg_src_preload_node = LIST_HEAD_INIT(init_css_set.mg_src_preload_node),
.mg_dst_preload_node = LIST_HEAD_INIT(init_css_set.mg_dst_preload_node),
.mg_node = LIST_HEAD_INIT(init_css_set.mg_node),

/*
Expand Down Expand Up @@ -1240,7 +1241,8 @@ static struct css_set *find_css_set(struct css_set *old_cset,
INIT_LIST_HEAD(&cset->threaded_csets);
INIT_HLIST_NODE(&cset->hlist);
INIT_LIST_HEAD(&cset->cgrp_links);
INIT_LIST_HEAD(&cset->mg_preload_node);
INIT_LIST_HEAD(&cset->mg_src_preload_node);
INIT_LIST_HEAD(&cset->mg_dst_preload_node);
INIT_LIST_HEAD(&cset->mg_node);

/* Copy the set of subsystem state objects generated in
Expand Down Expand Up @@ -1376,6 +1378,31 @@ static void cgroup_destroy_root(struct cgroup_root *root)
cgroup_free_root(root);
}

static inline struct cgroup *__cset_cgroup_from_root(struct css_set *cset,
struct cgroup_root *root)
{
struct cgroup *res_cgroup = NULL;

if (cset == &init_css_set) {
res_cgroup = &root->cgrp;
} else if (root == &cgrp_dfl_root) {
res_cgroup = cset->dfl_cgrp;
} else {
struct cgrp_cset_link *link;

list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
struct cgroup *c = link->cgrp;

if (c->root == root) {
res_cgroup = c;
break;
}
}
}

return res_cgroup;
}

/*
* look up cgroup associated with current task's cgroup namespace on the
* specified hierarchy
Expand All @@ -1391,22 +1418,8 @@ current_cgns_cgroup_from_root(struct cgroup_root *root)
rcu_read_lock();

cset = current->nsproxy->cgroup_ns->root_cset;
if (cset == &init_css_set) {
res = &root->cgrp;
} else if (root == &cgrp_dfl_root) {
res = cset->dfl_cgrp;
} else {
struct cgrp_cset_link *link;
res = __cset_cgroup_from_root(cset, root);

list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
struct cgroup *c = link->cgrp;

if (c->root == root) {
res = c;
break;
}
}
}
rcu_read_unlock();

BUG_ON(!res);
Expand All @@ -1422,22 +1435,7 @@ static struct cgroup *cset_cgroup_from_root(struct css_set *cset,
lockdep_assert_held(&cgroup_mutex);
lockdep_assert_held(&css_set_lock);

if (cset == &init_css_set) {
res = &root->cgrp;
} else if (root == &cgrp_dfl_root) {
res = cset->dfl_cgrp;
} else {
struct cgrp_cset_link *link;

list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
struct cgroup *c = link->cgrp;

if (c->root == root) {
res = c;
break;
}
}
}
res = __cset_cgroup_from_root(cset, root);

BUG_ON(!res);
return res;
Expand Down Expand Up @@ -2597,21 +2595,27 @@ int cgroup_migrate_vet_dst(struct cgroup *dst_cgrp)
*/
void cgroup_migrate_finish(struct cgroup_mgctx *mgctx)
{
LIST_HEAD(preloaded);
struct css_set *cset, *tmp_cset;

lockdep_assert_held(&cgroup_mutex);

spin_lock_irq(&css_set_lock);

list_splice_tail_init(&mgctx->preloaded_src_csets, &preloaded);
list_splice_tail_init(&mgctx->preloaded_dst_csets, &preloaded);
list_for_each_entry_safe(cset, tmp_cset, &mgctx->preloaded_src_csets,
mg_src_preload_node) {
cset->mg_src_cgrp = NULL;
cset->mg_dst_cgrp = NULL;
cset->mg_dst_cset = NULL;
list_del_init(&cset->mg_src_preload_node);
put_css_set_locked(cset);
}

list_for_each_entry_safe(cset, tmp_cset, &preloaded, mg_preload_node) {
list_for_each_entry_safe(cset, tmp_cset, &mgctx->preloaded_dst_csets,
mg_dst_preload_node) {
cset->mg_src_cgrp = NULL;
cset->mg_dst_cgrp = NULL;
cset->mg_dst_cset = NULL;
list_del_init(&cset->mg_preload_node);
list_del_init(&cset->mg_dst_preload_node);
put_css_set_locked(cset);
}

Expand Down Expand Up @@ -2651,7 +2655,7 @@ void cgroup_migrate_add_src(struct css_set *src_cset,
if (src_cset->dead)
return;

if (!list_empty(&src_cset->mg_preload_node))
if (!list_empty(&src_cset->mg_src_preload_node))
return;

src_cgrp = cset_cgroup_from_root(src_cset, dst_cgrp->root);
Expand All @@ -2664,7 +2668,7 @@ void cgroup_migrate_add_src(struct css_set *src_cset,
src_cset->mg_src_cgrp = src_cgrp;
src_cset->mg_dst_cgrp = dst_cgrp;
get_css_set(src_cset);
list_add_tail(&src_cset->mg_preload_node, &mgctx->preloaded_src_csets);
list_add_tail(&src_cset->mg_src_preload_node, &mgctx->preloaded_src_csets);
}

/**
Expand All @@ -2689,7 +2693,7 @@ int cgroup_migrate_prepare_dst(struct cgroup_mgctx *mgctx)

/* look up the dst cset for each src cset and link it to src */
list_for_each_entry_safe(src_cset, tmp_cset, &mgctx->preloaded_src_csets,
mg_preload_node) {
mg_src_preload_node) {
struct css_set *dst_cset;
struct cgroup_subsys *ss;
int ssid;
Expand All @@ -2708,16 +2712,16 @@ int cgroup_migrate_prepare_dst(struct cgroup_mgctx *mgctx)
if (src_cset == dst_cset) {
src_cset->mg_src_cgrp = NULL;
src_cset->mg_dst_cgrp = NULL;
list_del_init(&src_cset->mg_preload_node);
list_del_init(&src_cset->mg_src_preload_node);
put_css_set(src_cset);
put_css_set(dst_cset);
continue;
}

src_cset->mg_dst_cset = dst_cset;

if (list_empty(&dst_cset->mg_preload_node))
list_add_tail(&dst_cset->mg_preload_node,
if (list_empty(&dst_cset->mg_dst_preload_node))
list_add_tail(&dst_cset->mg_dst_preload_node,
&mgctx->preloaded_dst_csets);
else
put_css_set(dst_cset);
Expand Down Expand Up @@ -2963,7 +2967,8 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
goto out_finish;

spin_lock_irq(&css_set_lock);
list_for_each_entry(src_cset, &mgctx.preloaded_src_csets, mg_preload_node) {
list_for_each_entry(src_cset, &mgctx.preloaded_src_csets,
mg_src_preload_node) {
struct task_struct *task, *ntask;

/* all tasks in src_csets need to be migrated */
Expand Down Expand Up @@ -3609,21 +3614,21 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
static int cgroup_io_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;

return psi_show(seq, psi, PSI_IO);
}
static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;

return psi_show(seq, psi, PSI_MEM);
}
static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;

return psi_show(seq, psi, PSI_CPU);
}
Expand All @@ -3649,7 +3654,7 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
return -EBUSY;
}

psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
new = psi_trigger_create(psi, buf, nbytes, res);
if (IS_ERR(new)) {
cgroup_put(cgrp);
Expand Down
19 changes: 13 additions & 6 deletions kernel/sched/psi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -957,10 +957,16 @@ int psi_cgroup_alloc(struct cgroup *cgroup)
if (static_branch_likely(&psi_disabled))
return 0;

cgroup->psi.pcpu = alloc_percpu(struct psi_group_cpu);
if (!cgroup->psi.pcpu)
cgroup->psi = kmalloc(sizeof(struct psi_group), GFP_KERNEL);
if (!cgroup->psi)
return -ENOMEM;
group_init(&cgroup->psi);

cgroup->psi->pcpu = alloc_percpu(struct psi_group_cpu);
if (!cgroup->psi->pcpu) {
kfree(cgroup->psi);
return -ENOMEM;
}
group_init(cgroup->psi);
return 0;
}

Expand All @@ -969,10 +975,11 @@ void psi_cgroup_free(struct cgroup *cgroup)
if (static_branch_likely(&psi_disabled))
return;

cancel_delayed_work_sync(&cgroup->psi.avgs_work);
free_percpu(cgroup->psi.pcpu);
cancel_delayed_work_sync(&cgroup->psi->avgs_work);
free_percpu(cgroup->psi->pcpu);
/* All triggers must be removed by now */
WARN_ONCE(cgroup->psi.poll_states, "psi: trigger leak\n");
WARN_ONCE(cgroup->psi->poll_states, "psi: trigger leak\n");
kfree(cgroup->psi);
}

/**
Expand Down

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