Re: [RFC v2 14/83] Add range node kmem cache.

[Andiry Xu]

On Sun, Mar 11, 2018 at 4:55 AM, Nikolay Borisov
<n.borisov.lkml@xxxxxxxxx> wrote:
>
>
> On 10.03.2018 20:17, Andiry Xu wrote:
>> From: Andiry Xu <jix024@xxxxxxxxxxx>
>>
>> Range node specifies a range of [start, end]. and is managed by a red-black tree.
>> NOVA uses range node to manage NVM allocator and inodes being used.
>>
>> Signed-off-by: Andiry Xu <jix024@xxxxxxxxxxx>
>> ---
>>  fs/nova/nova.h  |  8 ++++++++
>>  fs/nova/super.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
>>  fs/nova/super.h |  2 ++
>>  3 files changed, 52 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/nova/nova.h b/fs/nova/nova.h
>> index ba7ffca..e0e85fb 100644
>> --- a/fs/nova/nova.h
>> +++ b/fs/nova/nova.h
>> @@ -301,6 +301,14 @@ static inline u64 nova_get_epoch_id(struct super_block *sb)
>>  }
>>
>>  #include "inode.h"
>> +
>> +/* A node in the RB tree representing a range of pages */
>> +struct nova_range_node {
>> +     struct rb_node node;
>> +     unsigned long range_low;
>> +     unsigned long range_high;
>> +};
>> +
>>  #include "bbuild.h"
>>
>>  /* ====================================================== */
>> diff --git a/fs/nova/super.c b/fs/nova/super.c
>> index f41cc04..aec1cd3 100644
>> --- a/fs/nova/super.c
>> +++ b/fs/nova/super.c
>> @@ -52,6 +52,7 @@ MODULE_PARM_DESC(nova_dbgmask, "Control debugging output");
>>  static struct super_operations nova_sops;
>>
>>  static struct kmem_cache *nova_inode_cachep;
>> +static struct kmem_cache *nova_range_node_cachep;
>>
>>
>>  /* FIXME: should the following variable be one per NOVA instance? */
>> @@ -686,6 +687,20 @@ static void nova_put_super(struct super_block *sb)
>>       sb->s_fs_info = NULL;
>>  }
>>
>> +inline void nova_free_range_node(struct nova_range_node *node)
>> +{
>> +     kmem_cache_free(nova_range_node_cachep, node);
>> +}
>> +
>> +inline struct nova_range_node *nova_alloc_range_node(struct super_block *sb)
>> +{
>> +     struct nova_range_node *p;
>> +
>> +     p = (struct nova_range_node *)
> nit: needless cast

Thanks. Will fix.

Andiry

>> +             kmem_cache_zalloc(nova_range_node_cachep, GFP_NOFS);
>> +     return p;
>> +}
>> +
>>  static struct inode *nova_alloc_inode(struct super_block *sb)
>>  {
>>       struct nova_inode_info *vi;
>> @@ -719,6 +734,17 @@ static void init_once(void *foo)
>>       inode_init_once(&vi->vfs_inode);
>>  }
>>
>> +static int __init init_rangenode_cache(void)
>> +{
>> +     nova_range_node_cachep = kmem_cache_create("nova_range_node_cache",
>> +                                     sizeof(struct nova_range_node),
>> +                                     0, (SLAB_RECLAIM_ACCOUNT |
>
>> +                                     SLAB_MEM_SPREAD), NULL);
>> +     if (nova_range_node_cachep == NULL)
>> +             return -ENOMEM;
>> +     return 0;
>> +}
>> +
>>  static int __init init_inodecache(void)
>>  {
>>       nova_inode_cachep = kmem_cache_create("nova_inode_cache",
>> @@ -740,6 +766,11 @@ static void destroy_inodecache(void)
>>       kmem_cache_destroy(nova_inode_cachep);
>>  }
>>
>> +static void destroy_rangenode_cache(void)
>> +{
>> +     kmem_cache_destroy(nova_range_node_cachep);
>> +}
>> +
>>
>>  /*
>>   * the super block writes are all done "on the fly", so the
>> @@ -781,20 +812,27 @@ static int __init init_nova_fs(void)
>>       nova_info("Arch new instructions support: CLWB %s\n",
>>                       support_clwb ? "YES" : "NO");
>>
>> -     rc = init_inodecache();
>> +     rc = init_rangenode_cache();
>>       if (rc)
>>               goto out;
>>
>> -     rc = register_filesystem(&nova_fs_type);
>> +     rc = init_inodecache();
>>       if (rc)
>>               goto out1;
>>
>> +     rc = register_filesystem(&nova_fs_type);
>> +     if (rc)
>> +             goto out2;
>> +
>>  out:
>>       NOVA_END_TIMING(init_t, init_time);
>>       return rc;
>>
>> -out1:
>> +out2:
>>       destroy_inodecache();
>> +
>> +out1:
>> +     destroy_rangenode_cache();
>>       goto out;
>>  }
>>
>> @@ -802,6 +840,7 @@ static void __exit exit_nova_fs(void)
>>  {
>>       unregister_filesystem(&nova_fs_type);
>>       destroy_inodecache();
>> +     destroy_rangenode_cache();
>>  }
>>
>>  MODULE_AUTHOR("Andiry Xu <jix024@xxxxxxxxxxx>");
>> diff --git a/fs/nova/super.h b/fs/nova/super.h
>> index cb53908..b478080 100644
>> --- a/fs/nova/super.h
>> +++ b/fs/nova/super.h
>> @@ -145,5 +145,7 @@ static inline struct nova_super_block *nova_get_super(struct super_block *sb)
>>  }
>>
>>  extern void nova_error_mng(struct super_block *sb, const char *fmt, ...);
>> +extern struct nova_range_node *nova_alloc_range_node(struct super_block *sb);
>> +extern void nova_free_range_node(struct nova_range_node *node);
>>
>>  #endif
>>