From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Lehmann Subject: dir_level explained? Date: Sun, 4 Oct 2015 11:56:47 +0200 Message-ID: <20151004095647.GC3177@schmorp.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Zig2J-0002Q6-SC for linux-f2fs-devel@lists.sourceforge.net; Sun, 04 Oct 2015 09:56:55 +0000 Received: from mail.nethype.de ([5.9.56.24]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1Zig2I-0007SU-Op for linux-f2fs-devel@lists.sourceforge.net; Sun, 04 Oct 2015 09:56:55 +0000 Received: from [10.0.0.5] (helo=doom.schmorp.de) by mail.nethype.de with esmtp (Exim 4.84) (envelope-from ) id 1Zig2C-00064d-Nf for linux-f2fs-devel@lists.sourceforge.net; Sun, 04 Oct 2015 09:56:48 +0000 Received: from [10.0.0.1] (helo=cerebro.laendle) by doom.schmorp.de with esmtp (Exim 4.84) (envelope-from ) id 1Zig2B-0003cd-UA for linux-f2fs-devel@lists.sourceforge.net; Sun, 04 Oct 2015 09:56:47 +0000 Received: from root by cerebro.laendle with local (Exim 4.84) (envelope-from ) id 1Zig2B-0000st-TV for linux-f2fs-devel@lists.sourceforge.net; Sun, 04 Oct 2015 11:56:47 +0200 Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-f2fs-devel@lists.sourceforge.net Hi! In all my tests I intentionally didn't play with dir_level, to get an idea of baseline performance. I also wasn't worried because my standard response to slow random reads is dmcache, but now that I realised I can't use dmcache with these drives, I got more interested in dir_level. If I understand it correctly, higher values of dir_level potentially waste more space but gain performance. However, I have no clue about what the trade-off really is. Could you explain what kind of extra space usage I can expect from higher levels of dir_level, or what the values mean? -- The choice of a Deliantra, the free code+content MORPG -----==- _GNU_ http://www.deliantra.net ----==-- _ generation ---==---(_)__ __ ____ __ Marc Lehmann --==---/ / _ \/ // /\ \/ / schmorp@schmorp.de -=====/_/_//_/\_,_/ /_/\_\ ------------------------------------------------------------------------------