diff options
| author | Tejun Heo <tj@kernel.org> | 2015-09-18 11:56:28 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2015-09-18 11:56:28 -0400 |
| commit | fc5ed1e95410ad73b2ab8f33cd90eb3bcf6c98a1 (patch) | |
| tree | 796ae052c16ea4a381df3e7c12982b4eeefd5e54 /kernel/cgroup.c | |
| parent | 49d1dc4b81797f88270832b11e9f73809e7e7209 (diff) | |
cgroup: replace cgroup_subsys->disabled tests with cgroup_subsys_enabled()
Replace cgroup_subsys->disabled tests in controllers with
cgroup_subsys_enabled(). cgroup_subsys_enabled() requires literal
subsys name as its parameter and thus can't be used for cgroup core
which iterates through controllers. For cgroup core, introduce and
use cgroup_ssid_enabled() which uses slower static_key_enabled() test
and can be indexed by subsys ID.
This leaves cgroup_subsys->disabled unused. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 361938911bd1..5703ba791b3d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -224,6 +224,19 @@ static void kill_css(struct cgroup_subsys_state *css); static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[], bool is_add); +/** + * cgroup_ssid_enabled - cgroup subsys enabled test by subsys ID + * @ssid: subsys ID of interest + * + * cgroup_subsys_enabled() can only be used with literal subsys names which + * is fine for individual subsystems but unsuitable for cgroup core. This + * is slower static_key_enabled() based test indexed by @ssid. + */ +static bool cgroup_ssid_enabled(int ssid) +{ + return static_key_enabled(cgroup_subsys_enabled_key[ssid]); +} + /* IDR wrappers which synchronize using cgroup_idr_lock */ static int cgroup_idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask) @@ -1482,7 +1495,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) for_each_subsys(ss, i) { if (strcmp(token, ss->legacy_name)) continue; - if (ss->disabled) + if (!cgroup_ssid_enabled(i)) continue; /* Mutually exclusive option 'all' + subsystem name */ @@ -1513,7 +1526,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) */ if (all_ss || (!one_ss && !opts->none && !opts->name)) for_each_subsys(ss, i) - if (!ss->disabled) + if (cgroup_ssid_enabled(i)) opts->subsys_mask |= (1 << i); /* @@ -2762,7 +2775,8 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, if (tok[0] == '\0') continue; for_each_subsys_which(ss, ssid, &tmp_ss_mask) { - if (ss->disabled || strcmp(tok + 1, ss->name)) + if (!cgroup_ssid_enabled(ssid) || + strcmp(tok + 1, ss->name)) continue; if (*tok == '+') { @@ -3320,7 +3334,7 @@ static int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) { int ret; - if (ss->disabled) + if (!cgroup_ssid_enabled(ss->id)) return 0; if (!cfts || cfts[0].name[0] == '\0') @@ -5082,7 +5096,7 @@ int __init cgroup_init(void) * disabled flag and cftype registration needs kmalloc, * both of which aren't available during early_init. */ - if (ss->disabled) + if (!cgroup_ssid_enabled(ssid)) continue; cgrp_dfl_root.subsys_mask |= 1 << ss->id; @@ -5217,7 +5231,8 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v) for_each_subsys(ss, i) seq_printf(m, "%s\t%d\t%d\t%d\n", ss->legacy_name, ss->root->hierarchy_id, - atomic_read(&ss->root->nr_cgrps), !ss->disabled); + atomic_read(&ss->root->nr_cgrps), + cgroup_ssid_enabled(i)); mutex_unlock(&cgroup_mutex); return 0; @@ -5508,7 +5523,6 @@ static int __init cgroup_disable(char *str) continue; static_branch_disable(cgroup_subsys_enabled_key[i]); - ss->disabled = 1; printk(KERN_INFO "Disabling %s control group subsystem\n", ss->name); break; |