On Thu, Sep 11, 2014 at 03:51:47PM +0200, Jan Kara wrote: > > I'm not yet convinced that just dropping > __jbd2_journal_clean_checkpoint_list() is the right thing to do. Some > periodic cleaning of checkpointed entries would seem reasonable so that we > don't save all that work for the moment we run out of space in the journal. > I'll think how to do that in a more efficient way... I'm sure Jan is aware of this, but for those following along, when we completely run out of space in the journal, and we have to do a formal checkpoint operation --- at which point, all file system activity has to grind to a halt, at which point *all* of the CPU cores will be dead in the water, which is bad for scalability, not to mention really annoying users whose terminals are stalled or whose web requests are completely stuck until the checkpoint completes. :-) So being able to clean up the journal so we don't have to do a forced checkpoint operation which requires waiting for I/O operations is rather important from a performance and usability point of view.... Cheers, - Ted -- 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
