So I was trying to understand what this report is about for some time but honestly I have failed... On Thu 17-02-22 20:10:04, Byungchul Park wrote: > [ 9.008161] =================================================== > [ 9.008163] DEPT: Circular dependency has been detected. > [ 9.008164] 5.17.0-rc1-00015-gb94f67143867-dirty #2 Tainted: G W > [ 9.008166] --------------------------------------------------- > [ 9.008167] summary > [ 9.008167] --------------------------------------------------- > [ 9.008168] *** DEADLOCK *** > [ 9.008168] > [ 9.008168] context A > [ 9.008169] [S] (unknown)(&(&journal->j_wait_transaction_locked)->dmap:0) > [ 9.008171] [W] wait(&(&journal->j_wait_commit)->dmap:0) > [ 9.008172] [E] event(&(&journal->j_wait_transaction_locked)->dmap:0) > [ 9.008173] > [ 9.008173] context B > [ 9.008174] [S] down_write(mapping.invalidate_lock:0) > [ 9.008175] [W] wait(&(&journal->j_wait_transaction_locked)->dmap:0) > [ 9.008176] [E] up_write(mapping.invalidate_lock:0) > [ 9.008177] > [ 9.008178] context C > [ 9.008179] [S] (unknown)(&(&journal->j_wait_commit)->dmap:0) > [ 9.008180] [W] down_write(mapping.invalidate_lock:0) > [ 9.008181] [E] event(&(&journal->j_wait_commit)->dmap:0) > [ 9.008181] > [ 9.008182] [S]: start of the event context > [ 9.008183] [W]: the wait blocked > [ 9.008183] [E]: the event not reachable So what situation is your tool complaining about here? Can you perhaps show it here in more common visualization like: TASK1 TASK2 does foo, grabs Z does X, grabs lock Y blocks on Z blocks on Y or something like that? Because I was not able to decipher this from the report even after trying for some time... Honza > [ 9.008184] --------------------------------------------------- > [ 9.008184] context A's detail > [ 9.008185] --------------------------------------------------- > [ 9.008186] context A > [ 9.008186] [S] (unknown)(&(&journal->j_wait_transaction_locked)->dmap:0) > [ 9.008187] [W] wait(&(&journal->j_wait_commit)->dmap:0) > [ 9.008188] [E] event(&(&journal->j_wait_transaction_locked)->dmap:0) > [ 9.008189] > [ 9.008190] [S] (unknown)(&(&journal->j_wait_transaction_locked)->dmap:0): > [ 9.008191] (N/A) > [ 9.008191] > [ 9.008192] [W] wait(&(&journal->j_wait_commit)->dmap:0): > [ 9.008193] prepare_to_wait (kernel/sched/wait.c:275) > [ 9.008197] stacktrace: > [ 9.008198] __schedule (kernel/sched/sched.h:1318 kernel/sched/sched.h:1616 kernel/sched/core.c:6213) > [ 9.008200] schedule (kernel/sched/core.c:6373 (discriminator 1)) > [ 9.008201] kjournald2 (fs/jbd2/journal.c:250) > [ 9.008203] kthread (kernel/kthread.c:377) > [ 9.008206] ret_from_fork (arch/x86/entry/entry_64.S:301) > [ 9.008209] > [ 9.008209] [E] event(&(&journal->j_wait_transaction_locked)->dmap:0): > [ 9.008210] __wake_up_common (kernel/sched/wait.c:108) > [ 9.008212] stacktrace: > [ 9.008213] dept_event (kernel/dependency/dept.c:2337) > [ 9.008215] __wake_up_common (kernel/sched/wait.c:109) > [ 9.008217] __wake_up_common_lock (./include/linux/spinlock.h:428 (discriminator 1) kernel/sched/wait.c:141 (discriminator 1)) > [ 9.008218] jbd2_journal_commit_transaction (fs/jbd2/commit.c:583) > [ 9.008221] kjournald2 (fs/jbd2/journal.c:214 (discriminator 3)) > [ 9.008223] kthread (kernel/kthread.c:377) > [ 9.008224] ret_from_fork (arch/x86/entry/entry_64.S:301) > [ 9.008226] --------------------------------------------------- > [ 9.008226] context B's detail > [ 9.008227] --------------------------------------------------- > [ 9.008228] context B > [ 9.008228] [S] down_write(mapping.invalidate_lock:0) > [ 9.008229] [W] wait(&(&journal->j_wait_transaction_locked)->dmap:0) > [ 9.008230] [E] up_write(mapping.invalidate_lock:0) > [ 9.008231] > [ 9.008232] [S] down_write(mapping.invalidate_lock:0): > [ 9.008233] ext4_da_write_begin (fs/ext4/truncate.h:21 fs/ext4/inode.c:2963) > [ 9.008237] stacktrace: > [ 9.008237] down_write (kernel/locking/rwsem.c:1514) > [ 9.008239] ext4_da_write_begin (fs/ext4/truncate.h:21 fs/ext4/inode.c:2963) > [ 9.008241] generic_perform_write (mm/filemap.c:3784) > [ 9.008243] ext4_buffered_write_iter (fs/ext4/file.c:269) > [ 9.008245] ext4_file_write_iter (fs/ext4/file.c:677) > [ 9.008247] new_sync_write (fs/read_write.c:504 (discriminator 1)) > [ 9.008250] vfs_write (fs/read_write.c:590) > [ 9.008251] ksys_write (fs/read_write.c:644) > [ 9.008253] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > [ 9.008255] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113) > [ 9.008258] > [ 9.008258] [W] wait(&(&journal->j_wait_transaction_locked)->dmap:0): > [ 9.008259] prepare_to_wait (kernel/sched/wait.c:275) > [ 9.008261] stacktrace: > [ 9.008261] __schedule (kernel/sched/sched.h:1318 kernel/sched/sched.h:1616 kernel/sched/core.c:6213) > [ 9.008263] schedule (kernel/sched/core.c:6373 (discriminator 1)) > [ 9.008264] wait_transaction_locked (fs/jbd2/transaction.c:184) > [ 9.008266] add_transaction_credits (fs/jbd2/transaction.c:248 (discriminator 3)) > [ 9.008267] start_this_handle (fs/jbd2/transaction.c:427) > [ 9.008269] jbd2__journal_start (fs/jbd2/transaction.c:526) > [ 9.008271] __ext4_journal_start_sb (fs/ext4/ext4_jbd2.c:105) > [ 9.008273] ext4_truncate (fs/ext4/inode.c:4164) > [ 9.008274] ext4_da_write_begin (./include/linux/fs.h:827 fs/ext4/truncate.h:23 fs/ext4/inode.c:2963) > [ 9.008276] generic_perform_write (mm/filemap.c:3784) > [ 9.008277] ext4_buffered_write_iter (fs/ext4/file.c:269) > [ 9.008279] ext4_file_write_iter (fs/ext4/file.c:677) > [ 9.008281] new_sync_write (fs/read_write.c:504 (discriminator 1)) > [ 9.008283] vfs_write (fs/read_write.c:590) > [ 9.008284] ksys_write (fs/read_write.c:644) > [ 9.008285] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > [ 9.008287] > [ 9.008288] [E] up_write(mapping.invalidate_lock:0): > [ 9.008288] ext4_da_get_block_prep (fs/ext4/inode.c:1795 fs/ext4/inode.c:1829) > [ 9.008291] --------------------------------------------------- > [ 9.008291] context C's detail > [ 9.008292] --------------------------------------------------- > [ 9.008292] context C > [ 9.008293] [S] (unknown)(&(&journal->j_wait_commit)->dmap:0) > [ 9.008294] [W] down_write(mapping.invalidate_lock:0) > [ 9.008295] [E] event(&(&journal->j_wait_commit)->dmap:0) > [ 9.008296] > [ 9.008297] [S] (unknown)(&(&journal->j_wait_commit)->dmap:0): > [ 9.008298] (N/A) > [ 9.008298] > [ 9.008299] [W] down_write(mapping.invalidate_lock:0): > [ 9.008299] ext4_da_write_begin (fs/ext4/truncate.h:21 fs/ext4/inode.c:2963) > [ 9.008302] stacktrace: > [ 9.008302] down_write (kernel/locking/rwsem.c:1514) > [ 9.008304] ext4_da_write_begin (fs/ext4/truncate.h:21 fs/ext4/inode.c:2963) > [ 9.008305] generic_perform_write (mm/filemap.c:3784) > [ 9.008307] ext4_buffered_write_iter (fs/ext4/file.c:269) > [ 9.008309] ext4_file_write_iter (fs/ext4/file.c:677) > [ 9.008311] new_sync_write (fs/read_write.c:504 (discriminator 1)) > [ 9.008312] vfs_write (fs/read_write.c:590) > [ 9.008314] ksys_write (fs/read_write.c:644) > [ 9.008315] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > [ 9.008316] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113) > [ 9.008318] > [ 9.008319] [E] event(&(&journal->j_wait_commit)->dmap:0): > [ 9.008320] __wake_up_common (kernel/sched/wait.c:108) > [ 9.008321] stacktrace: > [ 9.008322] __wake_up_common (kernel/sched/wait.c:109) > [ 9.008323] __wake_up_common_lock (./include/linux/spinlock.h:428 (discriminator 1) kernel/sched/wait.c:141 (discriminator 1)) > [ 9.008324] __jbd2_log_start_commit (fs/jbd2/journal.c:508) > [ 9.008326] jbd2_log_start_commit (fs/jbd2/journal.c:527) > [ 9.008327] __jbd2_journal_force_commit (fs/jbd2/journal.c:560) > [ 9.008329] jbd2_journal_force_commit_nested (fs/jbd2/journal.c:583) > [ 9.008331] ext4_should_retry_alloc (fs/ext4/balloc.c:670 (discriminator 3)) > [ 9.008332] ext4_da_write_begin (fs/ext4/inode.c:2965 (discriminator 1)) > [ 9.008334] generic_perform_write (mm/filemap.c:3784) > [ 9.008335] ext4_buffered_write_iter (fs/ext4/file.c:269) > [ 9.008337] ext4_file_write_iter (fs/ext4/file.c:677) > [ 9.008339] new_sync_write (fs/read_write.c:504 (discriminator 1)) > [ 9.008341] vfs_write (fs/read_write.c:590) > [ 9.008342] ksys_write (fs/read_write.c:644) > [ 9.008343] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > [ 9.008345] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113) > [ 9.008347] --------------------------------------------------- > [ 9.008348] information that might be helpful > [ 9.008348] --------------------------------------------------- > [ 9.008349] CPU: 0 PID: 89 Comm: jbd2/sda1-8 Tainted: G W 5.17.0-rc1-00015-gb94f67143867-dirty #2 > [ 9.008352] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > [ 9.008353] Call Trace: > [ 9.008354] <TASK> > [ 9.008355] dump_stack_lvl (lib/dump_stack.c:107) > [ 9.008358] print_circle (./arch/x86/include/asm/atomic.h:108 ./include/linux/atomic/atomic-instrumented.h:258 kernel/dependency/dept.c:157 kernel/dependency/dept.c:762) > [ 9.008360] ? print_circle (kernel/dependency/dept.c:1086) > [ 9.008362] cb_check_dl (kernel/dependency/dept.c:1104) > [ 9.008364] bfs (kernel/dependency/dept.c:860) > [ 9.008366] add_dep (kernel/dependency/dept.c:1423) > [ 9.008368] do_event.isra.25 (kernel/dependency/dept.c:1651) > [ 9.008370] ? __wake_up_common (kernel/sched/wait.c:108) > [ 9.008372] dept_event (kernel/dependency/dept.c:2337) > [ 9.008374] __wake_up_common (kernel/sched/wait.c:109) > [ 9.008376] __wake_up_common_lock (./include/linux/spinlock.h:428 (discriminator 1) kernel/sched/wait.c:141 (discriminator 1)) > [ 9.008379] jbd2_journal_commit_transaction (fs/jbd2/commit.c:583) > [ 9.008381] ? arch_stack_walk (arch/x86/kernel/stacktrace.c:24) > [ 9.008385] ? ret_from_fork (arch/x86/entry/entry_64.S:301) > [ 9.008387] ? dept_enable_hardirq (./arch/x86/include/asm/current.h:15 kernel/dependency/dept.c:241 kernel/dependency/dept.c:999 kernel/dependency/dept.c:1043 kernel/dependency/dept.c:1843) > [ 9.008389] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/irqflags.h:45 ./arch/x86/include/asm/irqflags.h:80 ./arch/x86/include/asm/irqflags.h:138 ./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) > [ 9.008392] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:103 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) > [ 9.008394] ? try_to_del_timer_sync (kernel/time/timer.c:1239) > [ 9.008396] kjournald2 (fs/jbd2/journal.c:214 (discriminator 3)) > [ 9.008398] ? prepare_to_wait_exclusive (kernel/sched/wait.c:431) > [ 9.008400] ? commit_timeout (fs/jbd2/journal.c:173) > [ 9.008402] kthread (kernel/kthread.c:377) > [ 9.008404] ? kthread_complete_and_exit (kernel/kthread.c:332) > [ 9.008407] ret_from_fork (arch/x86/entry/entry_64.S:301) > [ 9.008410] </TASK> -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
