From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Date: Mon, 10 Sep 2007 16:39:24 +0000 Subject: Re: [BTT PATCH] Major revamping (ver 2.0) Message-Id: <20070910163924.GL6892@kernel.dk> List-Id: References: <46E33802.9040209@hp.com> In-Reply-To: <46E33802.9040209@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-btrace@vger.kernel.org On Sat, Sep 08 2007, Alan D. Brunelle wrote: > After a lot of fighting with maintaining a tree-styled design (each trace > having it's own node), it was just getting too cumbersome to work in all > circumstances. Taking a clue from blkparse itself, I decided to just keep > track of IOs at queue time, and updating fields based upon later traces. > > The attached (large) patch works much faster, handles larger test cases > with less failures, and is managing some pretty large jobs I'm working on > (large Oracle-based DB analysis - 32-way box w/ lots of storage). > > I've also added a Q2Q seek distance feature - it's come in handy when > comparing results of IO scheduler choice: We can see what the incoming IO > seek distances are (at queue time), and then see how the scheduler itself > manages things (via merges & sorting) by looking at D2D seek distances > generated. > > As noted in the subject, I arbitrarily bumped this to version 2.00 as the > innards are so different. The documentation (btt/doc/btt.tex) has been > updated to reflect some minor output changes. I also fixed a bug dealing > with process name notification: there was a problem that if a new PID came > up with a name that was previously seen, btt wouldn't keep track of it > right. [When running with Oracle, a lot of processes have the same name but > different PIDs of course.] Applied (the 2nd full variant). -- Jens Axboe