----- Original Message ---- > From: Andrew Morton <[EMAIL PROTECTED]> > To: Arjan van de Ven <[EMAIL PROTECTED]> > Cc: Ingo Molnar <[EMAIL PROTECTED]>; [EMAIL PROTECTED]; > linux-kernel@vger.kernel.org; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL > PROTECTED]; [EMAIL PROTECTED] > Sent: Saturday, October 27, 2007 7:59:51 AM > Subject: Re: 2.6.24-rc1: First impressions > > On Fri, 26 Oct 2007 22:46:57 -0700 Arjan van de > Ven > 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. > > > > > > > another option... this is ext2.. didn't the ext2 reservation > stuff > get > > merged into -rc1? for ext3 that gave a 4x or so speed boost (much > > better sequential allocation pattern) > > > > Yes, one would expect that to make a large difference in > dd2/dd2-dir > and > dd3/dd3-dir - but only on SMP. On UP there's not enough concurrency > in the fs block allocator for any damage to occur. >
Just for the record the test are done on SMP. > Reservations won't affect dd1 though, and that went faster too. > This is the one result that surprised me most, as I did not really expect any big moves here. I am not complaining :-), but definitely it would be nice to understand the why. 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/
