diff options
| author | Ye Bin <yebin10@huawei.com> | 2023-12-11 14:25:44 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-12-12 18:25:46 +0300 |
| commit | 6c02757c936063f0631b4e43fe156f8c8f1f351f (patch) | |
| tree | b08ea34526f4d264322d9022dc2db246b7665b98 /fs/jbd2 | |
| parent | 619f75dae2cf117b1d07f27b046b9ffb071c4685 (diff) | |
| download | linux-6c02757c936063f0631b4e43fe156f8c8f1f351f.tar.xz | |
jbd2: fix soft lockup in journal_finish_inode_data_buffers()
There's issue when do io test:
WARN: soft lockup - CPU#45 stuck for 11s! [jbd2/dm-2-8:4170]
CPU: 45 PID: 4170 Comm: jbd2/dm-2-8 Kdump: loaded Tainted: G OE
Call trace:
dump_backtrace+0x0/0x1a0
show_stack+0x24/0x30
dump_stack+0xb0/0x100
watchdog_timer_fn+0x254/0x3f8
__hrtimer_run_queues+0x11c/0x380
hrtimer_interrupt+0xfc/0x2f8
arch_timer_handler_phys+0x38/0x58
handle_percpu_devid_irq+0x90/0x248
generic_handle_irq+0x3c/0x58
__handle_domain_irq+0x68/0xc0
gic_handle_irq+0x90/0x320
el1_irq+0xcc/0x180
queued_spin_lock_slowpath+0x1d8/0x320
jbd2_journal_commit_transaction+0x10f4/0x1c78 [jbd2]
kjournald2+0xec/0x2f0 [jbd2]
kthread+0x134/0x138
ret_from_fork+0x10/0x18
Analyzed informations from vmcore as follows:
(1) There are about 5k+ jbd2_inode in 'commit_transaction->t_inode_list';
(2) Now is processing the 855th jbd2_inode;
(3) JBD2 task has TIF_NEED_RESCHED flag;
(4) There's no pags in address_space around the 855th jbd2_inode;
(5) There are some process is doing drop caches;
(6) Mounted with 'nodioread_nolock' option;
(7) 128 CPUs;
According to informations from vmcore we know 'journal->j_list_lock' spin lock
competition is fierce. So journal_finish_inode_data_buffers() maybe process
slowly. Theoretically, there is scheduling point in the filemap_fdatawait_range_keep_errors().
However, if inode's address_space has no pages which taged with PAGECACHE_TAG_WRITEBACK,
will not call cond_resched(). So may lead to soft lockup.
journal_finish_inode_data_buffers
filemap_fdatawait_range_keep_errors
__filemap_fdatawait_range
while (index <= end)
nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end, PAGECACHE_TAG_WRITEBACK);
if (!nr_pages)
break; --> If 'nr_pages' is equal zero will break, then will not call cond_resched()
for (i = 0; i < nr_pages; i++)
wait_on_page_writeback(page);
cond_resched();
To solve above issue, add scheduling point in the journal_finish_inode_data_buffers();
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231211112544.3879780-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2')
| -rw-r--r-- | fs/jbd2/commit.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 9bdb377a348f..5e122586e06e 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -270,6 +270,7 @@ static int journal_finish_inode_data_buffers(journal_t *journal, if (!ret) ret = err; } + cond_resched(); spin_lock(&journal->j_list_lock); jinode->i_flags &= ~JI_COMMIT_RUNNING; smp_mb(); |