From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from resqmta-po-07v.sys.comcast.net ([96.114.154.166]:39696 "EHLO resqmta-po-07v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751276AbaL1AZr (ORCPT ); Sat, 27 Dec 2014 19:25:47 -0500 Message-ID: <549F4E0A.9090700@pobox.com> Date: Sat, 27 Dec 2014 16:25:46 -0800 From: Robert White MIME-Version: 1.0 To: Martin Steigerwald CC: Hugo Mills , linux-btrfs@vger.kernel.org Subject: Re: BTRFS free space handling still needs more work: Hangs again References: <3738341.y7uRQFcLJH@merkaba> <34633403.WlleJmkifE@merkaba> <549ECCD8.6090307@pobox.com> <1694920.QVWA5EcL6C@merkaba> In-Reply-To: <1694920.QVWA5EcL6C@merkaba> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 12/27/2014 08:01 AM, Martin Steigerwald wrote: >>>From how you write I get the impression that you think everyone else > beside you is just silly and dumb. Please stop this assumption. I may not > always get terms right, and I may make a mistake as with the wrong df > figure. But I also highly dislike to feel treated like someone who doesn´t > know a thing. Nope. I'm a systems theorist and I demand/require variable isolation. Not a question of "silly" or "dumb" but a question of "speaking with sufficient precision and clarity". For instance you speak of "having an impression" and then decide I've made an assumption. I define my position. Explain my terms. Give my examples. I also risk being utterly wrong because sometimes being completely wrong gets others to cut away misconceptions and assumptions. It annoys some people, but it gets results. You've been going around on this topic for how long? and just today Hugo "got" that your problem is becoming CPU bound (long process) instead of a hard lockup. We've stopped talking about "trees" and started talking about free space management. We've stopped talking about 17G of free space and gotten down to the 5 or so, plus you've gotten angry at me, tried to prove me an idiot, and so produced test cases and data that is absolutely clear including steps to reproduce. In real life I work on mission critical systems that can get people killed when they fail. So I have developed the reflex of tenacity in getting everyone using the same words, talking about the same concepts, giving concrete examples, and generally bringing the discussion to a very precise head. Example: I had two parties in conflict about a system. One party said that every time they did "an orderly shutdown" the device would hang in a way that took days to recover from. The other party would examine the device and say "could not reproduce". Turns out that the two parties were doing entirely different (but both correct) sequences for "orderly shutdown". They'd been having that conflict for more than a year. But since they both _knew_ what an "orderly shutdown" was, they _never_ analyzed what they were saying. (turns out one procedure left a chip in a state that it wouldn't restart until a capacitor discharged, and the other procedure did not.) So yea, when people make statements that "everybody understands" and those statements don't agree. I start slicing concepts off one at a time... It's not about "dumb" or "silly" it's about exact and accurate descriptions that have been stripped of assumptions and tribal knowledge. And I don't care if I come off looking like "the bad guy" because I don't believe in "the bad guy" at all when it comes to making things more clear and getting out of a communications deadlock. My only goal is "less broken". So occasionally annoying... but look... progress!