On Tue, Apr 26, 2016 at 01:27:02PM -0400, Benjamin Coddington wrote: > I'm doing some benchmarking on SCSI layout, and I ran into a case where > bonnie++ seemingly stopped making forward progress. > > bl_pg_init_write() wants to figure out how big the layout should be and uses > page_cache_next_hole() pretty aggressively if the inode size isn't equal to > the mapping. Problem is that page_cache_next_hole() is fairly stupid about > just walking through the page_cache radix tree by index. > > The end result is that for fairly large files (>4G) my machine spends all > its time in __radix_tree_lookup(), and I might as well just use regular NFS. Haha. One option is to simply optimize page_cache_next_hole, as that should be easy and the read-ahead could would benefit as well. Or make NFS pass through the writeback size and stop hacking around upper layers in the layout driver. Both seem like useful options. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
