git.openwrt.org Git - openwrt/openwrt.git/blob

   1 From 4bbdd9335a4784743a5ac30697f24972219559c2 Mon Sep 17 00:00:00 2001
   2 From: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
   3 Date: Wed, 22 May 2024 17:12:16 +0100
   4 Subject: [PATCH 1340/1350] mm/numa: Allow override of kernel's default NUMA
   5  policy
   6
   7 Add numa_policy kernel argument to allow overriding the kernel's default
   8 NUMA policy at boot time.
   9
  10 Syntax identical to what tmpfs accepts as it's mpol argument is accepted.
  11
  12 Some examples:
  13
  14  numa_policy=interleave
  15  numa_policy=interleave=skip-interleave
  16  numa_policy=bind:0-3,5,7,9-15
  17  numa_policy=bind=static:1-2
  18
  19 Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
  20 ---
  21  mm/mempolicy.c | 49 ++++++++++++++++++++++++++++++++++++++++++-------
  22  1 file changed, 42 insertions(+), 7 deletions(-)
  23
  24 --- a/mm/mempolicy.c
  25 +++ b/mm/mempolicy.c
  26 @@ -2974,7 +2974,9 @@ void __init numa_policy_init(void)
  27  /* Reset policy of current process to default */
  28  void numa_default_policy(void)
  29  {
  30 -       do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
  31 +       struct mempolicy *pol = &default_policy;
  32 +
  33 +       do_set_mempolicy(pol->mode, pol->flags, &pol->nodes);
  34  }
  35
  36  /*
  37 @@ -2992,7 +2994,6 @@ static const char * const policy_modes[]
  38  };
  39
  40
  41 -#ifdef CONFIG_TMPFS
  42  /**
  43   * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
  44   * @str:  string containing mempolicy to parse
  45 @@ -3005,13 +3006,18 @@ static const char * const policy_modes[]
  46   */
  47  int mpol_parse_str(char *str, struct mempolicy **mpol)
  48  {
  49 -       struct mempolicy *new = NULL;
  50 +       struct mempolicy *new;
  51         unsigned short mode_flags;
  52         nodemask_t nodes;
  53         char *nodelist = strchr(str, ':');
  54         char *flags = strchr(str, '=');
  55         int err = 1, mode;
  56
  57 +       if (*mpol)
  58 +               new = *mpol;
  59 +       else
  60 +               new = NULL;
  61 +
  62         if (flags)
  63                 *flags++ = '\0';        /* terminate mode string */
  64
  65 @@ -3090,9 +3096,16 @@ int mpol_parse_str(char *str, struct mem
  66                         goto out;
  67         }
  68
  69 -       new = mpol_new(mode, mode_flags, &nodes);
  70 -       if (IS_ERR(new))
  71 -               goto out;
  72 +       if (!new) {
  73 +               new = mpol_new(mode, mode_flags, &nodes);
  74 +               if (IS_ERR(new))
  75 +                       goto out;
  76 +       } else {
  77 +               atomic_set(&new->refcnt, 1);
  78 +               new->mode = mode;
  79 +               new->flags = mode_flags;
  80 +               new->home_node = NUMA_NO_NODE;
  81 +       }
  82
  83         /*
  84          * Save nodes for mpol_to_str() to show the tmpfs mount options
  85 @@ -3125,7 +3138,29 @@ out:
  86                 *mpol = new;
  87         return err;
  88  }
  89 -#endif /* CONFIG_TMPFS */
  90 +
  91 +static int __init setup_numapolicy(char *str)
  92 +{
  93 +       struct mempolicy pol = { }, *ppol = &pol;
  94 +       char buf[128];
  95 +       int ret;
  96 +
  97 +       if (str)
  98 +               ret = mpol_parse_str(str, &ppol);
  99 +       else
 100 +               ret = -EINVAL;
 101 +
 102 +       if (!ret) {
 103 +               default_policy = pol;
 104 +               mpol_to_str(buf, sizeof(buf), &pol);
 105 +               pr_info("NUMA default policy overridden to '%s'\n", buf);
 106 +       } else {
 107 +               pr_warn("Unable to parse numa_policy=\n");
 108 +       }
 109 +
 110 +       return ret == 0;
 111 +}
 112 +__setup("numa_policy=", setup_numapolicy);
 113
 114  /**
 115   * mpol_to_str - format a mempolicy structure for printing