----- Original Message ---- > From: Ingo Molnar <[EMAIL PROTECTED]> > To: Andrew Morton <[EMAIL PROTECTED]> > Cc: [EMAIL PROTECTED]; linux-kernel@vger.kernel.org; [EMAIL PROTECTED]; > [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED] > Sent: Friday, October 26, 2007 9:33:40 PM > Subject: Re: 2.6.24-rc1: First impressions > > > * Andrew Morton wrote: > > > > > dd1 - copy 16 GB from /dev/zero to local FS > > > > dd1-dir - same, but using O_DIRECT for output > > > > dd2/dd2-dir - copy 2x7.6 GB in parallel from /dev/zero to > local > FS > > > > dd3/dd3-dir - copy 3x5.2 GB in parallel from /dev/zero lo > local > FS > > > > net1 - copy 5.2 GB from NFS3 share to local FS > > > > mix3 - copy 3x5.2 GB from /dev/zero to local disk and two > NFS3 > shares > > > > > > > > I did the numbers for 2.6.19.2, 2.6.22.6 and 2.6.24-rc1. > All > units > > > > are MB/sec. > > > > > > > > test 2.6.19.2 2.6.22.6 2.6.24.-rc1 > > > > ---------------------------------------------------------------- > > > > dd1 28 50 96 > > > > dd1-dir 88 88 86 > > > > dd2 2x16.5 2x11 2x44.5 > > > > dd2-dir 2x44 2x44 2x43 > > > > dd3 3x9.8 3x8.7 3x30 > > > > dd3-dir 3x29.5 3x29.5 3x28.5 > > > > net1 30-33 50-55 37-52 > > > > mix3 17/32 25/50 > 96/35 > (disk/combined-network) > > > > > > wow, really nice results! > > > > Those changes seem suspiciously large to me. I wonder if > there's > less > > physical IO happening during the timed run, and correspondingly more > > afterwards. > > so a final 'sync' should be added to the test too, and the time > it > takes > factored into the bandwidth numbers? >
One of the reasons I do 15 GB transfers is to make sure that I am well above the possible page cache size. And of course I am doing a final sync to finish the runs :-) The sync is also running faster in 2.6.24-rc1. If I factor it in the results for dd1/dd3 are: test 2.6.19.2 2.6.22.6 2.6.24-rc1 sync time 18sec 19sec 6sec dd1 27.5 47.5 92 dd3 3x9.1 3x8.5 3x29 So basically including the sync time make 2.6.24-rc1 even more promosing. Now, I know that my benchmarks numbers are crude and show only a very small aspect of system performance. But - it is an aspect I care about a lot. And those benchmarks match my use-case pretty good. Cheers Martin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
