Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
cgroup: Add deprecation message to legacy freezer controller
As explained in the commit 76f969e8948d8 ("cgroup: cgroup v2 freezer"),
the original freezer is imperfect, some users may unwittingly rely on it
when there exists the alternative of v2. Print a message when it happens
and explain that in the docs.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
authored by
Michal Koutný
and committed by
Tejun Heo
78f6519e
fd4fd0a8
+8
-2
+4
Documentation/admin-guide/cgroup-v1/freezer-subsystem.rst
+4
Documentation/admin-guide/cgroup-v1/freezer-subsystem.rst
···
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This is the basic mechanism which should do the right thing for user space task
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in a simple scenario.
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+
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This freezer implementation is affected by shortcomings (see commit
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76f969e8948d8 ("cgroup: cgroup v2 freezer")) and cgroup v2 freezer is
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recommended.
+4
-2
kernel/cgroup/legacy_freezer.c
+4
-2
kernel/cgroup/legacy_freezer.c
···
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if (strcmp(buf, freezer_state_strs(0)) == 0)
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freeze = false;
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-
else if (strcmp(buf, freezer_state_strs(CGROUP_FROZEN)) == 0)
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else if (strcmp(buf, freezer_state_strs(CGROUP_FROZEN)) == 0) {
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pr_info_once("Freezing with imperfect legacy cgroup freezer. "
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"See cgroup.freeze of cgroup v2\n");
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freeze = true;
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-
else
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} else
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return -EINVAL;
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freezer_change_state(css_freezer(of_css(of)), freeze);