Re: [f2fs-dev] [PATCH] f2fs: use rw_sem instead of fs_lock(locks mutex)

2013-09-26 Thread Jin Xu
Great to see fs_locks is to be replaced. :) There is a potential problem with using r/w semaphore this way. The thread doing checkpoint might get starved if other threads are intensively locking the read semaphore for I/O. I noticed that Josef introduced a rwsem_is_contended for solving similar i

Re: [f2fs-dev][PATCH] f2fs: limit nr_iovecs in bio_alloc

2013-09-13 Thread Jin Xu
Did this patch pass the basic build? There seems have a typo regarding MAX_BIO_BLOCK. -- Jin On 13/09/2013 18:07, Chao Yu wrote: > This patch add macro MAX_BIO_BLOCKS to limit value of npages in > f2fs_bio_alloc, > it can avoid to return NULL in bio_alloc caused by npages is larger than > UIO_MAX

[PATCH] f2fs: optimize the victim searching loop slightly

2013-09-12 Thread Jin Xu
function call overhead - reduce multiplication and division operations - reduce unnecessary comparison operation Signed-off-by: Jin Xu --- fs/f2fs/gc.c | 15 +-- 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index a78b8e3..14187bf

Re: [f2fs-dev] [PATCH] f2fs: optimize fs_lock for better performance

2013-09-11 Thread Jin Xu
Hi, On 11/09/2013 21:19, Kim Jaegeuk wrote: Hi Russ, The usage of fs_locks is for the recovery, so it doesn't matter with stress-testing. Actually what I've concerned is that we should not grab two or more fs_locks in the same call path. Thanks, I am wondering why we don't use other kind of

[PATCH] f2fs: optimize gc for better performance

2013-09-04 Thread Jin Xu
From: Jin Xu This patch improves the gc efficiency by optimizing the victim selection policy. With this optimization, the random re-write performance could increase up to 20%. For f2fs, when disk is in shortage of free spaces, gc will selects dirty segments and moves valid blocks around for

Re: [PATCH] f2fs: optimize gc for better performance

2013-09-04 Thread Jin Xu
Yes, I will submit the patch later. On 05/09/2013 07:50, Jaegeuk Kim wrote: Hi Jin, 2013-09-04 (수), 21:17 +0800, Jin Xu: Hi Jaegeuk, On 04/09/2013 17:40, Jaegeuk Kim wrote: Hi Jin, 2013-09-04 (수), 07:59 +0800, Jin Xu: Hi Jaegeuk, On 03/09/2013 08:45, Jaegeuk Kim wrote: Hi Jin

Re: [PATCH] f2fs: optimize gc for better performance

2013-09-04 Thread Jin Xu
Hi Jaegeuk, On 04/09/2013 17:40, Jaegeuk Kim wrote: Hi Jin, 2013-09-04 (수), 07:59 +0800, Jin Xu: Hi Jaegeuk, On 03/09/2013 08:45, Jaegeuk Kim wrote: Hi Jin, [...] It seems that we can obtain the performance gain just by setting the MAX_VICTIM_SEARCH to 4096, for example. So, how about

Re: [PATCH] f2fs: optimize gc for better performance

2013-09-03 Thread Jin Xu
Hi Jaegeuk, On 03/09/2013 08:45, Jaegeuk Kim wrote: Hi Jin, [...] It seems that we can obtain the performance gain just by setting the MAX_VICTIM_SEARCH to 4096, for example. So, how about just adding an ending criteria like below? I agree that we could get the performance improvement by

Re: [PATCH] f2fs: optimize gc for better performance

2013-08-29 Thread Jin Xu
Hi Jaegeuk, On 08/29/2013 07:56 PM, Jaegeuk Kim wrote: Hi, 2013-08-29 (목), 08:48 +0800, Jin Xu: From: Jin Xu This patch improves the foreground gc efficiency by optimizing the victim selection policy. With this optimization, the random re-write performance could increase up to 20

[PATCH] f2fs: optimize gc for better performance

2013-08-28 Thread Jin Xu
From: Jin Xu This patch improves the foreground gc efficiency by optimizing the victim selection policy. With this optimization, the random re-write performance could increase up to 20%. For f2fs, foreground gc happens when disk is lack of free spaces, it selects dirty segments and moves valid

[PATCH] f2fs: avoid writing inode redundantly when creating a file

2013-08-15 Thread Jin Xu
From: Jin Xu In f2fs_write_inode, updating inode after f2fs_balance_fs is not a optimized way in the case that f2fs_gc is performed ahead. The inode page will be unnecessarily written out twice, one of which is in f2fs_gc->...->sync_node_pages and the other is in update_inode_page. Let&#x

[PATCH] f2fs: fix a deadlock in fsync

2013-08-05 Thread Jin Xu
From: Jin Xu This patch fixes a deadlock bug that occurs quite often when there are concurrent write and fsync on a same file. Following is the simplified call trace when tasks get hung. fsync thread: - f2fs_sync_file ... - f2fs_write_data_pages ... - update_extent_cache