linux_dsm_epyc7002/fs/f2fs
Chao Yu bb96a8d51e f2fs: enhance multithread performance
In ->writepages, we use writepages mutex lock to serialize all block
address allocation and page submitting pairs from different inodes.
This method makes our delayed dirty pages of one inode being written
continously as many as possible.

But there is one problem that we did not submit current cached bio in
protection region of writepages mutex lock, so there is a small chance
that we submit the one of other thread's as below, resulting in
splitting more bios.

thread 1			thread 2
->writepages
  lock(writepages)
  ->write_cache_pages
  unlock(writepages)
				  lock(writepages)
				  ->write_cache_pages
  ->f2fs_submit_merged_bio
				    ->writepage
				  unlock(writepages)

fs_mark-6535  [002] ....  2242.270230: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5766152, size = 524288
fs_mark-6536  [000] ....  2242.270361: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767176, size = 4096
fs_mark-6536  [000] ....  2242.270370: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, NODE, sector = 8138112, size = 4096
fs_mark-6535  [002] ....  2242.270776: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767184, size = 516096

This may really increase time of block layer works, and may cause
larger IO lantency.

This patch moves the submitting operation into region of writepages
mutex lock to avoid bio splits when concurrently writebacking is
intensive.

my test environment: virtual machine,
intel cpu i5 2500, 8GB size memory, 4GB size ramdisk

time fs_mark  -t  16  -L  1  -s  524288  -S  1  -d  /mnt/f2fs/

before:
real	0m4.244s
user	0m0.088s
sys	0m12.336s

after:
real	0m3.822s
user	0m0.072s
sys	0m10.760s

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-08-04 14:09:57 -07:00
..
acl.c f2fs: make posix_acl_create() safer and cleaner 2015-05-07 11:38:31 -07:00
acl.h f2fs: avoid deadlock on init_inode_metadata 2014-11-03 16:07:33 -08:00
checkpoint.c f2fs: fix to record dirty page count for symlink 2015-08-04 14:09:52 -07:00
crypto_fname.c f2fs crypto: clean up error handling in f2fs_fname_setup_filename 2015-06-01 16:21:08 -07:00
crypto_key.c f2fs crypto: delete an unnecessary check before the function call "key_put" 2015-08-04 14:09:52 -07:00
crypto_policy.c f2fs crypto: do not set encryption policy for non-directory by ioctl 2015-06-01 16:21:07 -07:00
crypto.c f2fs crypto: add alloc_bounce_page 2015-06-11 15:04:20 -07:00
data.c f2fs: enhance multithread performance 2015-08-04 14:09:57 -07:00
debug.c f2fs: fix building on 32-bit architectures 2015-06-01 16:20:53 -07:00
dir.c f2fs crypto: use per-inode tfm structure 2015-06-01 16:21:04 -07:00
f2fs_crypto.h f2fs crypto: remove alloc_page for bounce_page 2015-06-01 16:21:10 -07:00
f2fs.h f2fs: use extent_cache by default 2015-08-04 14:09:56 -07:00
file.c f2fs: convert inline_data for various fallocate 2015-08-04 14:09:53 -07:00
gc.c f2fs: make the function check_dnode have a return type of bool and change it's name to is_alive 2015-08-04 14:09:56 -07:00
gc.h f2fs: fix sparse warnings 2015-02-11 17:04:49 -08:00
hash.c f2fs: introduce dot and dotdot name check 2015-05-28 15:41:34 -07:00
inline.c f2fs: call set_page_dirty to attach i_wb for cgroup 2015-07-25 08:54:26 -07:00
inode.c f2fs: use extent_cache by default 2015-08-04 14:09:56 -07:00
Kconfig f2fs crypto: add f2fs encryption Kconfig 2015-05-28 15:41:46 -07:00
Makefile f2fs: introduce a shrinker for mounted fs 2015-08-04 14:09:54 -07:00
namei.c f2fs: restrict multimedia filename 2015-08-04 14:09:57 -07:00
node.c f2fs: shrink nat_cache entries 2015-08-04 14:09:55 -07:00
node.h f2fs: move existing definitions into f2fs.h 2015-05-28 15:41:27 -07:00
recovery.c f2fs: hide common code in f2fs_replace_block 2015-06-02 09:52:07 -07:00
segment.c f2fs: shrink extent_cache entries 2015-08-04 14:09:55 -07:00
segment.h Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block 2015-06-25 16:00:17 -07:00
shrinker.c f2fs: use extent_cache by default 2015-08-04 14:09:56 -07:00
super.c f2fs: use extent_cache by default 2015-08-04 14:09:56 -07:00
trace.c f2fs: add sbi and page pointer in f2fs_io_info 2015-05-28 15:41:32 -07:00
trace.h f2fs: add sbi and page pointer in f2fs_io_info 2015-05-28 15:41:32 -07:00
xattr.c f2fs crypto: add encryption policy and password salt support 2015-05-28 15:41:48 -07:00
xattr.h f2fs crypto: add encryption xattr support 2015-05-28 15:41:47 -07:00