http://bugzilla.kernel.org/show_bug.cgi?id=14830 Jan Kara <jack@xxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jack@xxxxxxx --- Comment #2 from Jan Kara <jack@xxxxxxx> 2010-01-18 21:50:38 --- There are two issues here - the first is that sync takes long - this is at the level of "don't do it when it hurts" kind of thing ;). So when you do heavy writing and call sync, it simply takes long time to flush all the caches to disk. If you think the time is inappropriately long, we can have a look at it but for that we'd need much more details like amount and nature of data writen (many small files vs a few large ones), time it takes sync to complete, speed of disks for sequential IO... The second issue is that nfsd blocks as well. Partly this might be because sync blocks writers (so that it can get it's work done in a finite time), partly it might be a limitation of ext4 because all metadata writes go through a journal which has a limited size and thus we have to copy data from the journal to final locations on disk once in a while and that usually leads to all writer processes blocking waiting for the journal space to be freed (which can take a longer time when 'sync' process is making disk busy with data writes). Note in the log file: This problem prevents production use of systems using this kernel. evokes a question: Do you have a kernel which behaved better for you? Which one? -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- 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
