On Mon, Jan 05 2009, Theodore Tso wrote: > So long-term, I suspect the hueristic which makes sense is that in the > case where there is an fsync() in progress, any writes which take > place as a result of that fsync (which includes the journal records as > well as ordered writes that are being forced out as a result of > data=ordered and which block the fsync from returning), should get a > hint which propagates down to the block layer that these writes *are* > synchronous in that someone is waiting for them to complete. They If someone is waiting for them, they are by definition sync! > shouldn't necessarily be prioritized ahead of other reads (unless they > are readahead operations that couldn't be combined with reads that > *are* synchronous that someone is waiting for completion), but they > should be prioritized ahead of asynchronous writes. And that is *exactly* what flagging the write as sync will do... -- Jens Axboe -- 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