cgroup: initialize cgrp_dfl_root_inhibit_ss_mask from !->dfl_files test (5de4fa13) · Commits · 戴 / test

cgrp_dfl_root_inhibit_ss_mask determines which subsystems are not supported on the default hierarchy and is currently initialized statically and just includes the debug subsystem. Now that there's cgroup_subsys->dfl_files, we can easily tell which subsystems support the default hierarchy or not. Let's initialize cgrp_dfl_root_inhibit_ss_mask by testing whether cgroup_subsys->dfl_files is NULL. After all, subsystems with NULL ->dfl_files aren't useable on the default hierarchy anyway. Signed-off-by:

Tejun Heo <tj@kernel.org> Acked-by:

Li Zefan <lizefan@huawei.com>

kernel/cgroup.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -156,11 +156,7 @@ static bool cgrp_dfl_root_visible;
		static bool cgroup_legacy_files_on_dfl;

		/* some controllers are not supported in the default hierarchy */
		static const unsigned int cgrp_dfl_root_inhibit_ss_mask = 0
		#ifdef CONFIG_CGROUP_DEBUG
		\| (1 << debug_cgrp_id)
		#endif
		;
		static unsigned int cgrp_dfl_root_inhibit_ss_mask;

		/* The list of hierarchy roots */

		@@ -4939,6 +4935,9 @@ int __init cgroup_init(void)
		if (cgroup_legacy_files_on_dfl && !ss->dfl_cftypes)
		ss->dfl_cftypes = ss->legacy_cftypes;

		if (!ss->dfl_cftypes)
		cgrp_dfl_root_inhibit_ss_mask \|= 1 << ss->id;

		if (ss->dfl_cftypes == ss->legacy_cftypes) {
		WARN_ON(cgroup_add_cftypes(ss, ss->dfl_cftypes));
		} else {

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