On 05/20/2011 08:23 AM, Chris Mason wrote: > Excerpts from Liu Bo's message of 2011-05-19 04:11:24 -0400: >> Introduce a new concept "sub transaction", >> the relation between transaction and sub transaction is >> >> transaction A ---> transid = x >> sub trans a(1) ---> sub_transid = x+1 >> sub trans a(2) ---> sub_transid = x+2 >> ... ... >> sub trans a(n-1) ---> sub_transid = x+n-1 >> sub trans a(n) ---> sub_transid = x+n >> transaction B ---> transid = x+n+1 >> ... ... >> >> And the most important is >> a) a trans handler's transid now gets value from sub transid instead of >> transid. >> b) when a transaction commits, transid may not added by 1, but depend on the >> biggest sub_transaction of the last neighbour transaction, >> i.e. >> B->transid = a(n)->transid + 1, >> (B->transid - A->transid) >= 1 >> c) we start a new sub transaction after a fsync. >> >> We also ship some 'trans->transid' to 'trans->transaction->transid' to >> ensure btrfs works well and to get rid of WARNings. >> >> These are used for the new log code. > > This is exactly what I had in mind. I need to read it harder and make > sure it interacts well with the directory logging code, but I love it. > > Thanks! >
It's so great that you like it. :) But I must NOTE again: Due to the bug which patch 8 fixed, the previous preformance statistics I posted sometime ago, like (*SPEED* : 4.7+ Mb/sec), are valueless and cannot be used as a basis any more... Hope that more people can get the patchset tested. thanks, liubo > -chris > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
