On Sat, Oct 16, 2010 at 12:03:00AM +1100, Nick Piggin wrote: > On Fri, Oct 15, 2010 at 09:59:43PM +1100, Dave Chinner wrote: > > My series uses i_lock only to protect i_state and i_ref. It does not > > need to protect any more of the inode than that as other locks > > protect the other list fields. As a result, it's still the inermost > > lock and there are no trylocks in the code at all. > We discussed it and I didn't think latencies would be any worse > a problem than they are today. I agreed it may be an issue and > pointed out there are ways forward to fix it. BTW. if a few trylocks are your biggest issue, this is a joke. I told you how they can be fixed with incremental patches on top of the series (which basically whittle down the lock coverage of the old inode_lock, and so IMO need to be done in small chunks well bisectable and with good rationale). So why you didn't submit a couple of incremental patches to do just that is beyond me. I've had prototypes in my tree actually to do that from a while back, but actually I'm thinking that using RCU may be a better way to go now that Linus has agreed on it and we have sketched a design to do slab-free-RCU. Either way, it's much easier to compare pros and cons of each, when they are done incrementally on top of the existing base. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
