src/patches/suse-2.6.27.31/patches.suse/module-ref-dynamic-alloc

   1 From: Takashi Iwai <tiwai@suse.de>
   2 Subject: [PATCH] Allocate module.ref array dynamically
   3 Patch-mainline:
   4 References: bnc#425240
   5
   6 This patch makes the module handling code to allocate the ref
   7 array of each module struct dynamically.  It saves both module
   8 disk space and memory footprints when number of CPUs is high
   9 like 4096.
  10
  11 Reference: Novell bnc#425240
  12         https://bugzilla.novell.com/show_bug.cgi?id=425240
  13
  14 Signed-off-by: Takashi Iwai <tiwai@suse.de>
  15
  16 ---
  17  include/linux/module.h |    2 +-
  18  kernel/module.c        |   21 ++++++++++++++++-----
  19  2 files changed, 17 insertions(+), 6 deletions(-)
  20
  21 Index: linux-2.6.27/kernel/module.c
  22 ===================================================================
  23 --- linux-2.6.27.orig/kernel/module.c
  24 +++ linux-2.6.27/kernel/module.c
  25 @@ -557,17 +557,28 @@ static char last_unloaded_module[MODULE_
  26
  27  #ifdef CONFIG_MODULE_UNLOAD
  28  /* Init the unload section of the module. */
  29 -static void module_unload_init(struct module *mod)
  30 +static int module_unload_init(struct module *mod)
  31  {
  32         unsigned int i;
  33 +       size_t refsize = nr_cpu_ids * sizeof(*mod->ref);
  34
  35         INIT_LIST_HEAD(&mod->modules_which_use_me);
  36 -       for (i = 0; i < NR_CPUS; i++)
  37 +
  38 +       mod->ref = kzalloc(refsize, GFP_KERNEL);
  39 +       if (!mod->ref) {
  40 +               mod->ref = vmalloc(refsize);
  41 +               if (!mod->ref)
  42 +                       return -ENOMEM;
  43 +               memset(mod->ref, 0, refsize);
  44 +       }
  45 +       for (i = 0; i < nr_cpu_ids; i++)
  46                 local_set(&mod->ref[i].count, 0);
  47         /* Hold reference count during initialization. */
  48         local_set(&mod->ref[raw_smp_processor_id()].count, 1);
  49         /* Backwards compatibility macros put refcount during init. */
  50         mod->waiter = current;
  51 +
  52 +       return 0;
  53  }
  54
  55  /* modules using other modules */
  56 @@ -647,6 +658,10 @@ static void module_unload_free(struct mo
  57                         }
  58                 }
  59         }
  60 +       if (is_vmalloc_addr(mod->ref))
  61 +               vfree(mod->ref);
  62 +       else
  63 +               kfree(mod->ref);
  64  }
  65
  66  #ifdef CONFIG_MODULE_FORCE_UNLOAD
  67 @@ -705,7 +720,7 @@ unsigned int module_refcount(struct modu
  68  {
  69         unsigned int i, total = 0;
  70
  71 -       for (i = 0; i < NR_CPUS; i++)
  72 +       for (i = 0; i < nr_cpu_ids; i++)
  73                 total += local_read(&mod->ref[i].count);
  74         return total;
  75  }
  76 @@ -894,8 +909,9 @@ static inline int use_module(struct modu
  77         return strong_try_module_get(b) == 0;
  78  }
  79
  80 -static inline void module_unload_init(struct module *mod)
  81 +static inline int module_unload_init(struct module *mod)
  82  {
  83 +       return 0;
  84  }
  85  #endif /* CONFIG_MODULE_UNLOAD */
  86
  87 @@ -2108,7 +2124,9 @@ static noinline struct module *load_modu
  88         mod = (void *)sechdrs[modindex].sh_addr;
  89
  90         /* Now we've moved module, initialize linked lists, etc. */
  91 -       module_unload_init(mod);
  92 +       err = module_unload_init(mod);
  93 +       if (err)
  94 +               goto free_unload;
  95
  96         /* add kobject, so we can reference it. */
  97         err = mod_sysfs_init(mod);
  98 Index: linux-2.6.27/include/linux/module.h
  99 ===================================================================
 100 --- linux-2.6.27.orig/include/linux/module.h
 101 +++ linux-2.6.27/include/linux/module.h
 102 @@ -343,7 +343,7 @@ struct module
 103         void (*exit)(void);
 104
 105         /* Reference counts */
 106 -       struct module_ref ref[NR_CPUS];
 107 +       struct module_ref *ref;
 108  #endif
 109  };
 110  #ifndef MODULE_ARCH_INIT