On Thu 16-06-16 12:45:28, Wang Shilong wrote: > From: Wang Shilong <wshilong@xxxxxxx> > > Lustre register some callbacks in ext4 to keep data consistency, > we see millons callbacks possibility on MDS for metadata operations. > > If there are many commit callbacks which might take some cpu > time, we can mark commit done before we call commit callback. > this can relax some thread waiting for commit finished, for example > transaction throttle in end transaction. > > Signed-off-by: Wang Shilong <wshilong@xxxxxxx> This is wrong - the commit callbacks will mark blocks free in bitmaps and ext4_should_retry_alloc() relies on the fact that once commit is reported as completed, all blocks freed in the committed transaction are really free in the bitmaps. This patch breaks the assumption. And Ted's optimization, which is BTW buggy, doesn't change anything on that... Honza -- Jan Kara <jack@xxxxxxxx> 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
