target/linux/brcm2708/patches-4.14/950-0136-cgroup-Disable-cgroup-memory-by-default.patch

   1 From 584bc4a6093ceb9aea07673185ee0084edc8690b Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Mon, 27 Nov 2017 17:14:54 +0000
   4 Subject: [PATCH 136/454] cgroup: Disable cgroup "memory" by default
   5
   6 Some Raspberry Pis have limited RAM and most users won't use the
   7 cgroup memory support so it is disabled by default. Enable with:
   8
   9     cgroup_enable=memory
  10
  11 See: https://github.com/raspberrypi/linux/issues/1950
  12
  13 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
  14 ---
  15  kernel/cgroup/cgroup.c | 30 ++++++++++++++++++++++++++++++
  16  1 file changed, 30 insertions(+)
  17
  18 --- a/kernel/cgroup/cgroup.c
  19 +++ b/kernel/cgroup/cgroup.c
  20 @@ -5162,6 +5162,8 @@ int __init cgroup_init_early(void)
  21  }
  22
  23  static u16 cgroup_disable_mask __initdata;
  24 +static u16 cgroup_enable_mask __initdata;
  25 +static int __init cgroup_disable(char *str);
  26
  27  /**
  28   * cgroup_init - cgroup initialization
  29 @@ -5200,6 +5202,12 @@ int __init cgroup_init(void)
  30
  31         mutex_unlock(&cgroup_mutex);
  32
  33 +       /* Apply an implicit disable... */
  34 +       cgroup_disable("memory");
  35 +
  36 +       /* ...knowing that an explicit enable will override it. */
  37 +       cgroup_disable_mask &= ~cgroup_enable_mask;
  38 +
  39         for_each_subsys(ss, ssid) {
  40                 if (ss->early_init) {
  41                         struct cgroup_subsys_state *css =
  42 @@ -5583,6 +5591,28 @@ static int __init cgroup_disable(char *s
  43  }
  44  __setup("cgroup_disable=", cgroup_disable);
  45
  46 +static int __init cgroup_enable(char *str)
  47 +{
  48 +       struct cgroup_subsys *ss;
  49 +       char *token;
  50 +       int i;
  51 +
  52 +       while ((token = strsep(&str, ",")) != NULL) {
  53 +               if (!*token)
  54 +                       continue;
  55 +
  56 +               for_each_subsys(ss, i) {
  57 +                       if (strcmp(token, ss->name) &&
  58 +                           strcmp(token, ss->legacy_name))
  59 +                               continue;
  60 +
  61 +                       cgroup_enable_mask |= 1 << i;
  62 +               }
  63 +       }
  64 +       return 1;
  65 +}
  66 +__setup("cgroup_enable=", cgroup_enable);
  67 +
  68  /**
  69   * css_tryget_online_from_dir - get corresponding css from a cgroup dentry
  70   * @dentry: directory dentry of interest