diff options
| author | brookxu <brookxu.cn@gmail.com> | 2020-08-15 08:10:44 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-08-19 12:04:36 -0400 |
| commit | c55ee7d202857b000531c2acfe8ce7cba5b77b5c (patch) | |
| tree | 1a0e2e1eba1610666f3ee926bd7b7a9f20bf1c9a /fs/ext4/mballoc.c | |
| parent | 7ca4fcba92edf82b05533a6e4f6b19a5fbec6f54 (diff) | |
ext4: add mb_debug logging when there are lost chunks
Lost chunks are when some other process raced with the current thread
to grab a particular block allocation. Add mb_debug log for
developers who wants to see how often this is happening for a
particular workload.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Link: https://lore.kernel.org/r/0a165ac0-1912-aebd-8a0d-b42e7cd1aea1@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/mballoc.c')
| -rw-r--r-- | fs/ext4/mballoc.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 51e2fe6094be..0993044cfe46 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2309,6 +2309,7 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac) struct ext4_sb_info *sbi; struct super_block *sb; struct ext4_buddy e4b; + unsigned int lost; sb = ac->ac_sb; sbi = EXT4_SB(sb); @@ -2456,22 +2457,24 @@ repeat: * We've been searching too long. Let's try to allocate * the best chunk we've found so far */ - ext4_mb_try_best_found(ac, &e4b); if (ac->ac_status != AC_STATUS_FOUND) { /* * Someone more lucky has already allocated it. * The only thing we can do is just take first * found block(s) - printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n"); */ + lost = (unsigned int)atomic_inc_return(&sbi->s_mb_lost_chunks); + mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %u\n", + ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start, + ac->ac_b_ex.fe_len, lost); + ac->ac_b_ex.fe_group = 0; ac->ac_b_ex.fe_start = 0; ac->ac_b_ex.fe_len = 0; ac->ac_status = AC_STATUS_CONTINUE; ac->ac_flags |= EXT4_MB_HINT_FIRST; cr = 3; - atomic_inc(&sbi->s_mb_lost_chunks); goto repeat; } } |