On Mon, Mar 09, 2015 at 04:05:03PM -0400, Trond Myklebust wrote: > The spec says that once all layouts that reference a given deviceid > have been returned, then we are only allowed to continue to cache > the deviceid if the metadata server supports notifications. This causes massive performance issues for object and block layout servers where a GETDEVICEINFO (or rather the client processing of it) is expensive. Also it increases the deadlock potential as the GETDEVICEINFO generally isn't safe for writeback under memory pressure (and yes, we'll need more fixes in that area). I've also filed an errata a while ago to update the language in the spec in this area to be consistent and not enforce this behavior: http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=4119 I think the right fix is to have a shrinker that allows the nfs client to retire unused devices on a lru basis under memory pressure. -- 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
