src/patches/suse-2.6.27.25/patches.suse/mem_cgroup_stat-dynamic-alloc

   1 From: Jan Blunck <jblunck@suse.de>
   2 Subject: Dynamically allocate struct mem_cgroup_stat_cpu memory
   3
   4 When increasing NR_CPUS to 4096 the size of struct mem_cgroup is growing to
   5 507904 bytes per instance on x86_64. This patch changes the allocation of
   6 these structures to use nr_cpu_ids instead. Although the init_mem_cgroup still
   7 is that huge since it stays statically allocated.
   8
   9 Signed-off-by: Jan Blunck <jblunck@suse.de>
  10 ---
  11  mm/memcontrol.c |   49 +++++++++++++++++++++++++++++++++++++++++--------
  12  1 file changed, 41 insertions(+), 8 deletions(-)
  13
  14 Index: b/mm/memcontrol.c
  15 ===================================================================
  16 --- a/mm/memcontrol.c
  17 +++ b/mm/memcontrol.c
  18 @@ -59,7 +59,7 @@ struct mem_cgroup_stat_cpu {
  19  } ____cacheline_aligned_in_smp;
  20
  21  struct mem_cgroup_stat {
  22 -       struct mem_cgroup_stat_cpu cpustat[NR_CPUS];
  23 +       struct mem_cgroup_stat_cpu *cpustat;
  24  };
  25
  26  /*
  27 @@ -143,6 +143,7 @@ struct mem_cgroup {
  28         struct mem_cgroup_stat stat;
  29  };
  30  static struct mem_cgroup init_mem_cgroup;
  31 +static struct mem_cgroup_stat_cpu init_mem_cgroup_stat_cpu[NR_CPUS];
  32
  33  /*
  34   * We use the lower bit of the page->page_cgroup pointer as a bit spin
  35 @@ -1097,23 +1098,54 @@ static void free_mem_cgroup_per_zone_inf
  36  static struct mem_cgroup *mem_cgroup_alloc(void)
  37  {
  38         struct mem_cgroup *mem;
  39 +       struct mem_cgroup_stat_cpu *cpustat;
  40 +       size_t statsize = nr_cpu_ids * sizeof(*cpustat);
  41
  42 -       if (sizeof(*mem) < PAGE_SIZE)
  43 -               mem = kmalloc(sizeof(*mem), GFP_KERNEL);
  44 -       else
  45 +       if (sizeof(*mem) > PAGE_SIZE) {
  46                 mem = vmalloc(sizeof(*mem));
  47 -
  48 -       if (mem)
  49 +               if (!mem)
  50 +                       goto out;
  51                 memset(mem, 0, sizeof(*mem));
  52 +       } else
  53 +               mem = kzalloc(sizeof(*mem), GFP_KERNEL);
  54 +
  55 +       if (!mem)
  56 +               goto out;
  57 +
  58 +       if (statsize > PAGE_SIZE) {
  59 +               cpustat = vmalloc(statsize);
  60 +               if (!cpustat)
  61 +                       goto out_mem;
  62 +               memset(cpustat, 0, statsize);
  63 +       } else
  64 +               cpustat = kzalloc(statsize, GFP_KERNEL);
  65 +
  66 +       if (!cpustat)
  67 +               goto out_mem;
  68 +
  69 +       mem->stat.cpustat = cpustat;
  70         return mem;
  71 +
  72 +out_mem:
  73 +       if (is_vmalloc_addr(mem))
  74 +               vfree(mem);
  75 +       else
  76 +               kfree(mem);
  77 +out:
  78 +       return NULL;
  79  }
  80
  81  static void mem_cgroup_free(struct mem_cgroup *mem)
  82  {
  83 -       if (sizeof(*mem) < PAGE_SIZE)
  84 -               kfree(mem);
  85 +       if (is_vmalloc_addr(mem->stat.cpustat))
  86 +               vfree(mem->stat.cpustat);
  87         else
  88 +               kfree(mem->stat.cpustat);
  89 +
  90 +       if (is_vmalloc_addr(mem))
  91                 vfree(mem);
  92 +       else
  93 +               kfree(mem);
  94  }
  95
  96
  97 @@ -1125,6 +1157,7 @@ mem_cgroup_create(struct cgroup_subsys *
  98
  99         if (unlikely((cont->parent) == NULL)) {
 100                 mem = &init_mem_cgroup;
 101 +               mem->stat.cpustat = &init_mem_cgroup_stat_cpu[0];
 102                 page_cgroup_cache = KMEM_CACHE(page_cgroup, SLAB_PANIC);
 103         } else {
 104                 mem = mem_cgroup_alloc();