[sheepdog] [PATCH v2 0/3] let sd_inode_set_vid() to support range update

[Robin Dong]

From: Robin Dong <sanbai at taobao.com>

After testing in large data environment, we find out that the performance of
sheepdog will reduce raplidly when data is bigger than 2TB.
The reason is in sd_inode_set_vid(), it only set one 'vid' at one time, and
need to read ext-node out, set vid, then write ext-node back, which need read
and write 4MB data.
To promote the performance, we let sd_inode_set_vid() to set range of vids one
time and introduce cache for B-tree code, therefore it only need read and write
4MB data at once after set many vids.

Signed-off-by: Robin Dong <sanbai at taobao.com>
---
v1-->v2:
  1. add 'no rationale' for NUMBER_OF_CACHE
  2. change function name from 'cache_xxx' to 'icache_xxx'
  3. add comment to explain the cache can't run in
     concurrent env.
  4. replace 'writer_c/reader_c' to 'cache_writer/cache_reader'

Robin Dong (3):
  lib: create new function set_vid_for_btree()
  lib: change interface sd_inode_set_vid()
  lib: add cache version of writer and reader

 dog/dog.h                |   7 +-
 include/sheepdog_proto.h |   4 +-
 lib/sd_inode.c           | 200 ++++++++++++++++++++++++++++++++++++++---------
 sheep/http/oalloc.c      |   4 +-
 sheep/sheep_priv.h       |   7 +-
 sheepfs/volume.c         |   6 +-
 6 files changed, 182 insertions(+), 46 deletions(-)

-- 
1.7.12.4