On Sun, 6 Oct 2002, Jens Axboe wrote:
On Sun, Oct 06 2002, Peter Osterlund wrote:
Hi!
I have updated the packet writing patch for use with kernel 2.5.40.
http://w1.894.telia.com/~u89404340/patches/packet/2.5/packet-2.5.40.patch.bz...
There are no exciting new features, only adaptions to kernel changes. Although this version works, I get the feeling that it is slower than it used to be. It looks like the packet driver isn't fed enough simultaneous requests. Are there any special tricks I should use to make the deadline I/O scheduler work well with a stacking block driver?
If you can help me quantify what exactly is slower (or why it feels slower), then I can surely help you do a general solution for this. I would be inclined to say that you should just printk every request extracted from the io scheduler with the old version and with deadline and compare them. There just might be some obvious bug there.
One thing I noticed is that the i/o scheduler sometimes feeds requests in reverse order to the cd. This may be OK for hard disks, but seems to be bad for cds, at least my cd. Is this supposed to happen with the new i/o scheduler? Oct 6 22:23:08 pengo kernel: usb-storage: 28 00 00 00 60 80 00 00 0f 00 00 00 Oct 6 22:23:08 pengo kernel: usb-storage: 2a 00 00 00 62 40 00 00 20 00 00 00 Oct 6 22:23:10 pengo kernel: usb-storage: 2a 00 00 00 62 20 00 00 20 00 00 00 Oct 6 22:23:11 pengo kernel: usb-storage: 2a 00 00 00 62 00 00 00 20 00 00 00 Oct 6 22:23:13 pengo kernel: usb-storage: 2a 00 00 00 61 e0 00 00 20 00 00 00 Oct 6 22:23:14 pengo kernel: usb-storage: 2a 00 00 00 61 c0 00 00 20 00 00 00 Oct 6 22:23:15 pengo kernel: usb-storage: 2a 00 00 00 61 a0 00 00 20 00 00 00 Oct 6 22:23:16 pengo kernel: usb-storage: 2a 00 00 00 61 80 00 00 20 00 00 00 Oct 6 22:23:18 pengo kernel: usb-storage: 2a 00 00 00 61 60 00 00 20 00 00 00 Oct 6 22:23:19 pengo kernel: usb-storage: 2a 00 00 00 61 40 00 00 20 00 00 00 Oct 6 22:23:20 pengo kernel: usb-storage: 2a 00 00 00 61 20 00 00 20 00 00 00 Oct 6 22:23:21 pengo kernel: usb-storage: 2a 00 00 00 61 00 00 00 20 00 00 00 Oct 6 22:23:23 pengo kernel: usb-storage: 2a 00 00 00 60 e0 00 00 20 00 00 00 Oct 6 22:23:24 pengo kernel: usb-storage: 2a 00 00 00 60 c0 00 00 20 00 00 00 Oct 6 22:23:25 pengo kernel: usb-storage: 2a 00 00 00 60 a0 00 00 20 00 00 00 Oct 6 22:23:26 pengo kernel: usb-storage: 2a 00 00 00 07 a0 00 00 20 00 00 00 Oct 6 22:23:28 pengo kernel: usb-storage: 2a 00 00 00 07 80 00 00 20 00 00 00 Oct 6 22:23:29 pengo kernel: usb-storage: 2a 00 00 00 07 60 00 00 20 00 00 00 Oct 6 22:23:30 pengo kernel: usb-storage: 2a 00 00 00 07 40 00 00 20 00 00 00 Oct 6 22:23:31 pengo kernel: usb-storage: 2a 00 00 00 07 20 00 00 20 00 00 00 Oct 6 22:23:33 pengo kernel: usb-storage: 2a 00 00 00 07 00 00 00 20 00 00 00 Oct 6 22:23:34 pengo kernel: usb-storage: 2a 00 00 00 06 e0 00 00 20 00 00 00 Oct 6 22:23:35 pengo kernel: usb-storage: 2a 00 00 00 06 c0 00 00 20 00 00 00 Oct 6 22:23:36 pengo kernel: usb-storage: 2a 00 00 00 06 a0 00 00 20 00 00 00 Oct 6 22:23:38 pengo kernel: usb-storage: 2a 00 00 00 06 80 00 00 20 00 00 00 Oct 6 22:23:39 pengo kernel: usb-storage: 2a 00 00 00 06 60 00 00 20 00 00 00 Oct 6 22:23:40 pengo kernel: usb-storage: 2a 00 00 00 06 40 00 00 20 00 00 00 Oct 6 22:23:41 pengo kernel: usb-storage: 2a 00 00 00 06 20 00 00 20 00 00 00 Oct 6 22:23:43 pengo kernel: usb-storage: 2a 00 00 00 06 00 00 00 20 00 00 00 Oct 6 22:23:44 pengo kernel: usb-storage: 2a 00 00 00 05 e0 00 00 20 00 00 00 Oct 6 22:23:45 pengo kernel: usb-storage: 2a 00 00 00 05 c0 00 00 20 00 00 00 Oct 6 22:23:46 pengo kernel: usb-storage: 2a 00 00 00 07 c0 00 00 20 00 00 00 Oct 6 22:23:47 pengo kernel: usb-storage: 2a 00 00 00 60 80 00 00 20 00 00 00 Oct 6 22:23:49 pengo kernel: usb-storage: 2a 00 00 00 62 60 00 00 20 00 00 00 Oct 6 22:23:50 pengo kernel: usb-storage: 2a 00 00 00 62 80 00 00 20 00 00 00 Oct 6 22:23:50 pengo kernel: usb-storage: 2a 00 00 00 62 a0 00 00 20 00 00 00 Oct 6 22:23:50 pengo kernel: usb-storage: 2a 00 00 00 62 c0 00 00 20 00 00 00 Oct 6 22:23:51 pengo kernel: usb-storage: 2a 00 00 00 62 e0 00 00 20 00 00 00 Oct 6 22:23:52 pengo kernel: usb-storage: 2a 00 00 00 63 00 00 00 20 00 00 00 Oct 6 22:23:53 pengo kernel: usb-storage: 2a 00 00 00 63 20 00 00 20 00 00 00 Oct 6 22:23:53 pengo kernel: usb-storage: 2a 00 00 00 63 40 00 00 20 00 00 00 Oct 6 22:23:54 pengo kernel: usb-storage: 2a 00 00 00 63 60 00 00 20 00 00 00 Oct 6 22:23:54 pengo kernel: usb-storage: 2a 00 00 00 63 80 00 00 20 00 00 00 Oct 6 22:23:55 pengo kernel: usb-storage: 2a 00 00 00 63 a0 00 00 20 00 00 00 Oct 6 22:23:56 pengo kernel: usb-storage: 2a 00 00 00 63 c0 00 00 20 00 00 00 Oct 6 22:23:56 pengo kernel: usb-storage: 2a 00 00 00 63 e0 00 00 20 00 00 00 Oct 6 22:23:57 pengo kernel: usb-storage: 2a 00 00 00 64 00 00 00 20 00 00 00 Oct 6 22:23:57 pengo kernel: usb-storage: 2a 00 00 00 64 20 00 00 20 00 00 00 Oct 6 22:23:58 pengo kernel: usb-storage: 2a 00 00 00 64 40 00 00 20 00 00 00 Oct 6 22:23:59 pengo kernel: usb-storage: 2a 00 00 00 64 60 00 00 20 00 00 00 Oct 6 22:23:59 pengo kernel: usb-storage: 2a 00 00 00 64 80 00 00 20 00 00 00 Oct 6 22:24:00 pengo kernel: usb-storage: 2a 00 00 00 64 a0 00 00 20 00 00 00 Oct 6 22:24:00 pengo kernel: usb-storage: 2a 00 00 00 64 c0 00 00 20 00 00 00 Oct 6 22:24:00 pengo kernel: usb-storage: 2a 00 00 00 64 e0 00 00 20 00 00 00 Oct 6 22:24:01 pengo kernel: usb-storage: 2a 00 00 00 65 00 00 00 20 00 00 00 Oct 6 22:24:02 pengo kernel: usb-storage: 2a 00 00 00 65 20 00 00 20 00 00 00 Oct 6 22:24:03 pengo kernel: usb-storage: 2a 00 00 00 65 40 00 00 20 00 00 00 Oct 6 22:24:03 pengo kernel: usb-storage: 2a 00 00 00 65 60 00 00 20 00 00 00 Oct 6 22:24:03 pengo kernel: usb-storage: 2a 00 00 00 65 80 00 00 20 00 00 00 Oct 6 22:24:04 pengo kernel: usb-storage: 2a 00 00 00 65 a0 00 00 20 00 00 00 Oct 6 22:24:05 pengo kernel: usb-storage: 2a 00 00 00 65 c0 00 00 20 00 00 00 Oct 6 22:24:06 pengo kernel: usb-storage: 2a 00 00 00 65 e0 00 00 20 00 00 00 Oct 6 22:24:06 pengo kernel: usb-storage: 2a 00 00 00 66 00 00 00 20 00 00 00 -- Peter Osterlund - petero2@telia.com http://w1.894.telia.com/~u89404340