On Wed 25-03-09 18:29:10, Alexander Beregalov wrote: > 2009/3/25 Jan Kara <jack@xxxxxxx>: > > On Wed 25-03-09 18:18:43, Alexander Beregalov wrote: > >> 2009/3/25 Jan Kara <jack@xxxxxxx>: > >> >> > So, I think I need to try it on 2.6.29-rc7 again. > >> >> I've looked into this. Obviously, what's happenning is that we delete > >> >> an inode and jbd2_journal_release_jbd_inode() finds inode is just under > >> >> writeout in transaction commit and thus it waits. But it gets never woken > >> >> up and because it has a handle from the transaction, every one eventually > >> >> blocks on waiting for a transaction to finish. > >> >> But I don't really see how that can happen. The code is really > >> >> straightforward and everything happens under j_list_lock... Strange. > >> > BTW: Is the system SMP? > >> No, it is UP system. > > Even stranger. And do you have CONFIG_PREEMPT set? > > > >> The bug exists even in 2.6.29, I posted it with a new topic. > > OK, I've sort-of expected this. > > CONFIG_PREEMPT_RCU=y > CONFIG_PREEMPT_RCU_TRACE=y > # CONFIG_PREEMPT_NONE is not set > # CONFIG_PREEMPT_VOLUNTARY is not set > CONFIG_PREEMPT=y > CONFIG_DEBUG_PREEMPT=y > # CONFIG_PREEMPT_TRACER is not set > > config is attached. Thanks for the data. I still don't see how the wakeup can get lost. The process even cannot be preempted when we are in the section protected by j_list_lock... Can you send me a disassembly of functions jbd2_journal_release_jbd_inode() and journal_submit_data_buffers() so that I can see whether the compiler has not reordered something unexpectedly? Thanks. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
