From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: Re: speed up dirty data cleaning Date: Thu, 7 Nov 2013 18:49:04 -0800 Message-ID: <20131108024904.GL3842@kmo> References: <527B90EF.10404@profihost.ag> <527BAF4B.9080609@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <527BAF4B.9080609-2Lf/h1ldwEHR5kwTpVNS9A@public.gmane.org> Sender: linux-bcache-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stefan Priebe - Profihost AG Cc: "linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-bcache@vger.kernel.org On Thu, Nov 07, 2013 at 04:18:35PM +0100, Stefan Priebe - Profihost AG wrote: > After some time it seems to start writing out all the data at a good > disk speed. > > But how does bcache determine when to write which kind of data out of > bcache. There's a PD controller that tries to keep the amount of dirty data at writeback_percent percentage of your cache size. But, since the dirty data account was _still_ broken, that would screw up that PD controller. Workaround is to set writeback_percent to 0