From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: Re: can't get bache's sequential_cutoff to work Date: Tue, 23 Jul 2013 22:31:01 +0200 Message-ID: <51EEE805.7090200@profihost.ag> References: <51EE9056.7030903@profihost.ag> <51EEDC73.5020101@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51EEDC73.5020101-2Lf/h1ldwEHR5kwTpVNS9A@public.gmane.org> Sender: linux-bcache-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jack Wang Cc: "linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Kent Overstreet List-Id: linux-bcache@vger.kernel.org It works fine if do really small block writes like this: # dd if=/dev/zero of=/dev/bcache0 bs=100 count=5000000 Can anybody tell me why? Stefan Am 23.07.2013 21:41, schrieb Stefan Priebe: > It's 3.10 with bcache Updates from kent's for 3.10 branch. > > Stefan > > This mail was sent with my iPhone. > > Am 23.07.2013 um 18:00 schrieb Jack Wang >: > >> Hi Stefan, >> >> Strange, I tested bcache 2 month ago, mostly bcache-3.2 branch in >> writeback mode, it works as claimed. >> >> which kernel version are you using? >> >> Jack >> >> >> 2013/7/23 Stefan Priebe - Profihost AG > > >> >> Hi, >> >> maybe i missed something or maybe i'm just wrong. >> >> >> # cat /sys/block/bcache2/bcache/sequential_cutoff >> 512k >> >> # cat /sys/block/bcache2/bcache/stats_five_minute/bypassed >> 64.3M >> >> # dd if=/dev/zero of=/mnt/bcache2/ttt bs=4M count=1000 oflag=direct >> 1000+0 records in >> 1000+0 records out >> 4194304000 bytes (4,2 GB) copied, 11,0348 s, 380 MB/s >> >> # cat /sys/block/bcache2/bcache/stats_five_minute/bypassed >> 69.3M >> >> I also see only IOP/s an writes go to the SSD but not to the disk >> behind. What's wrong? >> >> Greets, >> Stefan >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-bcache" in >> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >> >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >>