From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Turmel Subject: Re: RAID 5,6 sequential writing seems slower in newer kernels Date: Thu, 3 Dec 2015 09:37:52 -0500 Message-ID: <566053C0.4060706@turmel.org> References: <20151202010745.GC9812@www5.open-std.org> <565F03F2.3070803@turmel.org> <565F1035.10800@turmel.org> <565F136F.2090709@turmel.org> <565FA66C.8060907@turmel.org> <565FAB29.9060405@turmel.org> <565FC548.1060302@turmel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Robert Kierski , Dallas Clement Cc: "linux-raid@vger.kernel.org" List-Id: linux-raid.ids On 12/03/2015 08:43 AM, Robert Kierski wrote: > This is why I use Direct-IO to the bare metal block device instead of going through the FS. Rather than discussing the real problem, we're off in the weed talking about whether the tests should be using O_SYNC and whether there is a problem introduced in the latest version of the FS. It's not off in the weeds for Dallas, the OP. > FS's and cache are very good at hiding the problems of those things below them and prevent you from exercising the code you're interested in debugging. Yep, you seem to have a real problem. Phil