On Monday 19 February 2007 14:56, Evgeniy Polyakov wrote: > On Mon, Feb 19, 2007 at 02:38:13PM +0100, Eric Dumazet ([EMAIL PROTECTED]) wrote: > > On Monday 19 February 2007 12:41, Evgeniy Polyakov wrote: > > > > 1 microsecond ? Are you kidding ? We want no more than 50 ns. > > > > > > Theory again. > > > > Theory is nice, but I personally prefer oprofile :) > > I base my comments on real facts. > > We *want* 50 ns tcp lookups (2 cache line misses, one with reader intent, > > one for exclusive access intent) > > I said that your words are theory in previous mails :) > > Current code works 10 times worse than you expect. > > > > Existing table does not scale that good - I created (1<<20)/2 (to cover > > > only established part) entries table and filled it with 1 million of > > > random entries -search time is about half of microsecod. > > > > I use exactly 1^20 slots, not 1^19 (see commit > > dbca9b2750e3b1ee6f56a616160ccfc12e8b161f , where I changed layout of > > ehash table so that two chains (established/timewait) are on the same > > cache line. every cache miss *counts*) > > Forget about cache misses and cache lines - we have a hash table, only > part of which is used (part for time-wait sockets, part for established > ones).
No you didnt not read my mail. Current ehash is not as decribed by you. > > Anyway, even with 2^20 (i.e. when the whole table is only used for > established sockets) search time is about 360-370 nsec on 3.7 GHz Core > Duo (only one CPU is used) with 2 GB of ram. Your tests are user land, so unfortunatly are biased... (Unless you use hugetlb data ?) - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
