libcgroup-0.41-api.c-fix-order-of-memory-subsystem-parameters.patch

   1 From 72a9e0c3d4f8daca9f7dc389edbc1013d7c0d808 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Nikola=20Forr=C3=B3?= <nforro@redhat.com>
   3 Date: Fri, 8 Apr 2016 17:00:19 +0200
   4 Subject: [PATCH] api.c: fix order of memory subsystem parameters generated by
   5  cgsnapshot
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 Order of parameters usually doesn't matter, but that's not the case with
  11 memory.limit_in_bytes and memory.memsw.limit_in_bytes. When the latter
  12 is first in the list of parameters, the resulting configuration is not
  13 loadable with cgconfigparser.
  14
  15 This happens because when a cgroup is created, both memory.limit_in_bytes
  16 and memory.memsw.limit_in_bytes parameters are initialized to highest
  17 value possible (RESOURCE_MAX). And because memory.memsw.limit_in_bytes
  18 must be always higher or equal to memory.limit_in_bytes, it's impossible
  19 to change its value first.
  20
  21 Make sure that after constructing parameter list of memory subsystem,
  22 the mentioned parameters are in correct order.
  23
  24 Signed-off-by: Nikola Forró <nforro@redhat.com>
  25 ---
  26  src/api.c | 24 ++++++++++++++++++++++++
  27  1 file changed, 24 insertions(+)
  28
  29 diff --git a/src/api.c b/src/api.c
  30 index 0bf0615..f5da553 100644
  31 --- a/src/api.c
  32 +++ b/src/api.c
  33 @@ -2651,6 +2651,30 @@ int cgroup_get_cgroup(struct cgroup *cgroup)
  34                         }
  35                 }
  36                 closedir(dir);
  37 +
  38 +               if (! strcmp(cgc->name, "memory")) {
  39 +                       /*
  40 +                        * Make sure that memory.limit_in_bytes is placed before
  41 +                        * memory.memsw.limit_in_bytes in the list of values
  42 +                        */
  43 +                       int memsw_limit = -1;
  44 +                       int mem_limit = -1;
  45 +
  46 +                       for (j = 0; j < cgc->index; j++) {
  47 +                               if (! strcmp(cgc->values[j]->name,
  48 +                                                               "memory.memsw.limit_in_bytes"))
  49 +                                       memsw_limit = j;
  50 +                               else if (! strcmp(cgc->values[j]->name,
  51 +                                                                       "memory.limit_in_bytes"))
  52 +                                       mem_limit = j;
  53 +                       }
  54 +
  55 +                       if (memsw_limit >= 0 && memsw_limit < mem_limit) {
  56 +                               struct control_value *val = cgc->values[memsw_limit];
  57 +                               cgc->values[memsw_limit] = cgc->values[mem_limit];
  58 +                               cgc->values[mem_limit] = val;
  59 +                       }
  60 +               }
  61         }
  62
  63         /* Check if the group really exists or not */
  64 --
  65 2.4.11
  66