Re: splice/vmsplice performance test results
From: Jim Schutt
Date: Fri Nov 17 2006 - 12:22:40 EST
On Thu, 2006-11-16 at 21:25 +0100, Jens Axboe wrote:
> On Thu, Nov 16 2006, Jim Schutt wrote:
> > Hi,
> >
> > My test program can do one of the following:
> >
> > send data:
> > A) read() from file into buffer, write() buffer into socket
> > B) mmap() section of file, write() that into socket, munmap()
> > C) splice() from file to pipe, splice() from pipe to socket
> >
> > receive data:
> > 1) read() from socket into buffer, write() buffer into file
> > 2) ftruncate() to extend file, mmap() new extent, read()
> > from socket into new extent, munmap()
> > 3) read() from socket into buffer, vmsplice() buffer to
> > pipe, splice() pipe to file (using the double-buffer trick)
> >
> > Here's the results, using:
> > - 64 KiB buffer, mmap extent, or splice
> > - 1 MiB TCP window
> > - 16 GiB data sent across network
> >
> > A) from /dev/zero -> 1) to /dev/null : 857 MB/s (6.86 Gb/s)
> >
> > A) from file -> 1) to /dev/null : 472 MB/s (3.77 Gb/s)
> > B) from file -> 1) to /dev/null : 366 MB/s (2.93 Gb/s)
> > C) from file -> 1) to /dev/null : 854 MB/s (6.83 Gb/s)
> >
> > A) from /dev/zero -> 1) to file : 375 MB/s (3.00 Gb/s)
> > A) from /dev/zero -> 2) to file : 150 MB/s (1.20 Gb/s)
> > A) from /dev/zero -> 3) to file : 286 MB/s (2.29 Gb/s)
> >
> > I had (naively) hoped the read/vmsplice/splice combination would
> > run at the same speed I can write a file, i.e. at about 450 MB/s
> > on my setup. Do any of my numbers seem bogus, so I should look
> > harder at my test program?
>
> Could be read-ahead playing in here, I'd have to take a closer look at
> the generated io patterns to say more about that. Any chance you can
> capture iostat or blktrace info for such a run to compare that goes to
> the disk?
I've attached a file with iostat and vmstat results for the case
where I read from a socket and write a file, vs. the case where I
read from a socket and use vmsplice/splice to write the file.
(Sorry it's not inline - my mailer locks up when I try to
include the file.)
Would you still like blktrace info for these two cases?
-- Jim
Here's 'iostat -dx 5' on the receiver, when it reads from a socket
and writes to a file:
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdd 0.00 0.00 0.00 0.20 0.00 0.40 0.00 0.20 2.00 0.00 0.00 0.00 0.00
sde 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
md0 0.00 0.00 0.00 0.20 0.00 0.40 0.00 0.20 2.00 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.20 0.00 571.26 0.00 142574.45 0.00 71287.23 249.58 0.89 1.56 0.43 24.51
sdc 0.00 0.00 0.00 576.85 0.00 142558.08 0.00 71279.04 247.13 1.02 1.77 0.42 23.95
sdd 0.00 1.20 0.60 577.45 4.79 142545.91 2.40 71272.95 246.61 1.16 2.00 0.54 31.46
sde 0.00 0.60 0.00 573.85 0.00 142607.58 0.00 71303.79 248.51 1.34 2.33 0.54 30.74
md0 0.00 0.00 0.60 2301.40 4.79 570286.03 2.40 285143.01 247.74 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.20 0.00 750.40 0.00 187265.80 0.00 93632.90 249.55 1.10 1.46 0.42 31.36
sdc 0.00 1.40 0.00 755.80 0.00 187236.80 0.00 93618.40 247.73 1.30 1.72 0.43 32.64
sdd 0.00 2.80 0.00 751.20 0.00 187253.40 0.00 93626.70 249.27 1.53 2.04 0.55 41.36
sde 0.00 0.20 0.00 767.40 0.00 187235.20 0.00 93617.60 243.99 1.65 2.15 0.54 41.52
md0 0.00 0.00 0.00 3029.40 0.00 748991.20 0.00 374495.60 247.24 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 1.00 0.00 771.26 0.00 187299.20 0.00 93649.60 242.85 1.21 1.57 0.44 33.61
sdc 0.00 1.60 0.00 765.87 0.00 187262.28 0.00 93631.14 244.51 1.33 1.73 0.45 34.49
sdd 0.00 1.00 0.00 739.72 0.00 187258.48 0.00 93629.24 253.15 1.43 1.93 0.55 40.56
sde 0.00 0.80 0.00 744.31 0.00 187227.15 0.00 93613.57 251.54 1.85 2.48 0.56 41.68
md0 0.00 0.00 0.00 3025.55 0.00 749047.11 0.00 374523.55 247.57 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.40 0.20 751.30 3.19 185520.36 1.60 92760.18 246.87 1.15 1.52 0.45 33.85
sdc 0.00 1.20 0.00 741.12 0.00 185344.51 0.00 92672.26 250.09 1.38 1.87 0.45 33.21
sdd 0.00 2.59 0.00 756.09 0.00 185470.06 0.00 92735.03 245.30 1.53 2.03 0.54 40.64
sde 0.00 0.40 0.00 744.71 0.00 185379.64 0.00 92689.82 248.93 1.72 2.31 0.54 40.16
md0 0.00 0.00 0.20 3002.79 3.19 742992.02 1.60 371496.01 247.42 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 753.80 0.00 186913.80 0.00 93456.90 247.96 1.20 1.59 0.45 34.00
sdc 0.00 1.80 0.00 756.40 0.00 186971.20 0.00 93485.60 247.19 1.35 1.79 0.44 33.60
sdd 0.00 1.00 0.00 751.00 0.00 186895.40 0.00 93447.70 248.86 1.54 2.05 0.55 41.20
sde 0.00 1.00 0.00 755.60 0.00 186832.00 0.00 93416.00 247.26 1.76 2.33 0.56 42.00
md0 0.00 0.00 0.00 3019.20 0.00 747254.00 0.00 373627.00 247.50 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 744.89 0.00 184891.58 0.00 92445.79 248.21 1.17 1.58 0.45 33.59
sdc 0.00 4.21 0.00 742.08 0.00 184734.27 0.00 92367.13 248.94 1.41 1.90 0.45 33.75
sdd 0.00 0.60 0.00 759.72 0.00 184695.19 0.00 92347.60 243.11 1.52 2.00 0.55 41.68
sde 0.00 0.80 0.00 737.88 0.00 184989.18 0.00 92494.59 250.71 1.79 2.43 0.56 41.68
md0 0.00 0.00 0.00 2991.18 0.00 739566.73 0.00 369783.37 247.25 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.80 0.00 736.53 0.00 184289.42 0.00 92144.71 250.21 1.19 1.61 0.46 34.09
sdc 0.00 1.00 0.00 743.51 0.00 184225.15 0.00 92112.57 247.78 1.39 1.86 0.46 34.57
sdd 0.00 0.60 0.00 747.70 0.00 184270.86 0.00 92135.43 246.45 1.60 2.13 0.56 41.68
sde 0.00 0.80 0.00 754.69 0.00 184199.60 0.00 92099.80 244.07 1.69 2.24 0.56 42.16
md0 0.00 0.00 0.00 2985.83 0.00 737036.13 0.00 368518.06 246.84 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 1.00 0.00 753.09 0.00 183984.23 0.00 91992.12 244.30 1.20 1.59 0.45 33.61
sdc 0.00 0.80 0.00 741.52 0.00 184097.41 0.00 92048.70 248.27 1.35 1.83 0.45 33.05
sdd 0.00 0.60 0.00 735.13 0.00 184121.56 0.00 92060.78 250.46 1.48 2.01 0.55 40.72
sde 0.00 0.40 0.00 742.12 0.00 183975.65 0.00 91987.82 247.91 1.76 2.38 0.56 41.20
md0 0.00 0.00 0.00 2969.86 0.00 734952.50 0.00 367476.25 247.47 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 1.60 0.00 741.40 0.00 183925.00 0.00 91962.50 248.08 1.11 1.50 0.45 33.44
sdc 0.00 0.80 0.00 738.80 0.00 183760.00 0.00 91880.00 248.73 1.36 1.85 0.45 33.36
sdd 0.00 0.40 0.00 749.40 0.00 183790.60 0.00 91895.30 245.25 1.52 2.02 0.55 41.04
sde 0.00 0.40 0.00 742.20 0.00 183752.80 0.00 91876.40 247.58 1.71 2.30 0.55 40.80
md0 0.00 0.00 0.00 2980.20 0.00 736559.60 0.00 368279.80 247.15 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 201.40 0.00 50070.60 0.00 25035.30 248.61 0.30 1.48 0.46 9.20
sdc 0.00 0.40 0.00 198.40 0.00 50134.40 0.00 25067.20 252.69 0.38 1.90 0.46 9.20
sdd 0.00 0.20 0.00 203.00 0.00 50102.60 0.00 25051.30 246.81 0.49 2.40 0.56 11.36
sde 0.00 0.00 0.00 209.80 0.00 50146.00 0.00 25073.00 239.02 0.48 2.28 0.53 11.04
md0 0.00 0.00 0.00 808.00 0.00 199122.40 0.00 99561.20 246.44 0.00 0.00 0.00 0.00
and here's 'vmstat 5' during the same time, at 5 sec intervals:
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 0 596 931948 244 18152 0 0 0 0 359 31 0 0 100 0
1 0 596 279084 240 648088 0 0 2 318336 25708 3892 0 54 40 7
1 0 596 7108 108 910932 0 0 0 374689 28552 5537 0 64 29 7
1 0 596 8216 108 908124 0 0 0 375773 28805 3841 0 67 26 7
2 1 596 7812 88 908512 0 0 2 372315 28616 3348 0 66 26 7
1 0 596 7904 88 908368 0 0 0 372839 28687 3455 0 67 26 7
2 0 596 7632 88 908624 0 0 0 369063 28381 3380 0 68 26 7
1 0 596 8540 100 907712 0 0 2 369179 28405 3394 0 68 25 7
1 0 596 7088 120 909272 0 0 6 368593 28351 3430 0 67 25 8
1 0 596 7876 108 908492 0 0 0 367826 28282 3342 0 68 24 7
And here's 'iostat -dx 5' on the receiver, when it reads from a socket
and uses vmsplice/splice to write the file:
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdd 0.00 0.20 0.00 0.40 0.00 3.40 0.00 1.70 8.50 0.00 0.00 0.00 0.00
sde 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
md0 0.00 0.00 0.00 0.60 0.00 3.40 0.00 1.70 5.67 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 250.30 0.00 62179.24 0.00 31089.62 248.42 0.34 1.34 0.40 9.90
sdc 0.00 0.00 0.60 249.10 4.79 62166.87 2.40 31083.43 248.98 0.42 1.67 0.41 10.14
sdd 0.00 1.00 0.00 253.89 0.00 62200.40 0.00 31100.20 244.99 0.49 1.94 0.53 13.49
sde 0.00 0.00 0.00 249.10 0.00 62166.87 0.00 31083.43 249.56 0.56 2.26 0.53 13.25
md0 0.00 0.00 0.60 1003.39 4.79 248713.37 2.40 124356.69 247.73 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 551.60 0.00 138981.40 0.00 69490.70 251.96 0.75 1.37 0.43 23.52
sdc 0.00 0.40 0.00 545.40 0.00 138878.80 0.00 69439.40 254.64 1.06 1.93 0.44 23.76
sdd 0.00 0.00 0.00 582.80 0.00 138822.40 0.00 69411.20 238.20 1.28 2.20 0.55 31.92
sde 0.00 0.40 0.00 579.80 0.00 138780.80 0.00 69390.40 239.36 1.19 2.05 0.54 31.20
md0 0.00 0.00 0.00 2260.60 0.00 555465.00 0.00 277732.50 245.72 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 539.68 0.00 137531.66 0.00 68765.83 254.84 0.75 1.39 0.43 23.09
sdc 0.00 0.20 0.00 537.47 0.00 137494.39 0.00 68747.19 255.82 1.05 1.96 0.43 23.01
sdd 0.00 0.00 0.00 578.36 0.00 137462.12 0.00 68731.06 237.68 1.32 2.28 0.58 33.43
sde 0.00 0.60 0.00 578.76 0.00 137487.78 0.00 68743.89 237.56 1.22 2.12 0.57 33.27
md0 0.00 0.00 0.00 2234.87 0.00 549974.35 0.00 274987.17 246.09 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 537.45 0.00 137488.65 0.00 68744.32 255.82 0.71 1.33 0.42 22.63
sdc 0.00 0.20 0.00 537.85 0.00 137495.42 0.00 68747.71 255.64 1.03 1.92 0.43 23.11
sdd 0.00 0.00 0.00 579.08 0.00 137461.35 0.00 68730.68 237.38 1.28 2.22 0.56 32.35
sde 0.00 0.20 0.00 573.31 0.00 137447.01 0.00 68723.51 239.74 1.17 2.04 0.55 31.39
md0 0.00 0.00 0.00 2228.09 0.00 549892.43 0.00 274946.22 246.80 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 540.40 0.00 137667.40 0.00 68833.70 254.75 0.74 1.38 0.42 22.96
sdc 0.00 0.20 0.00 538.20 0.00 137634.60 0.00 68817.30 255.73 1.05 1.96 0.44 23.52
sdd 0.00 0.00 0.00 581.60 0.00 137643.20 0.00 68821.60 236.66 1.30 2.23 0.57 33.36
sde 0.00 0.00 0.00 580.60 0.00 137641.60 0.00 68820.80 237.07 1.22 2.10 0.56 32.72
md0 0.00 0.00 0.00 2241.00 0.00 550586.80 0.00 275293.40 245.69 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 536.33 0.00 137057.29 0.00 68528.64 255.55 0.73 1.35 0.43 22.91
sdc 0.00 0.20 0.00 535.53 0.00 136950.70 0.00 68475.35 255.73 1.04 1.93 0.43 22.91
sdd 0.00 0.20 0.00 578.64 0.00 136950.10 0.00 68475.05 236.67 1.28 2.20 0.56 32.65
sde 0.00 0.00 0.00 577.84 0.00 137124.15 0.00 68562.08 237.30 1.20 2.07 0.56 32.26
md0 0.00 0.00 0.00 2233.73 0.00 549359.68 0.00 274679.84 245.94 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.20 0.00 547.60 0.00 136721.80 0.00 68360.90 249.67 0.78 1.43 0.44 24.24
sdc 0.00 0.20 0.00 535.00 0.00 136815.40 0.00 68407.70 255.73 1.06 1.99 0.46 24.40
sdd 0.00 0.60 0.00 565.00 0.00 136840.00 0.00 68420.00 242.19 1.25 2.22 0.59 33.28
sde 0.00 0.00 0.00 571.20 0.00 136664.00 0.00 68332.00 239.26 1.22 2.14 0.56 32.16
md0 0.00 0.00 0.00 2214.80 0.00 545761.20 0.00 272880.60 246.42 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.20 0.00 541.12 0.00 136218.96 0.00 68109.48 251.74 0.77 1.42 0.45 24.35
sdc 0.00 0.20 0.00 532.53 0.00 136133.53 0.00 68066.77 255.63 1.07 2.01 0.45 23.79
sdd 0.00 0.20 0.00 562.87 0.00 136132.53 0.00 68066.27 241.85 1.25 2.22 0.55 30.98
sde 0.00 0.40 0.00 571.66 0.00 136114.97 0.00 68057.49 238.11 1.15 2.01 0.52 29.94
md0 0.00 0.00 0.00 2209.18 0.00 544600.00 0.00 272300.00 246.52 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.20 0.00 547.60 0.00 135878.80 0.00 67939.40 248.14 0.80 1.46 0.45 24.72
sdc 0.00 0.20 0.00 538.20 0.00 135837.20 0.00 67918.60 252.39 1.03 1.91 0.46 24.72
sdd 0.00 0.00 0.00 554.80 0.00 135854.40 0.00 67927.20 244.87 1.15 2.07 0.56 30.80
sde 0.00 0.00 0.00 560.60 0.00 135904.00 0.00 67952.00 242.43 1.26 2.24 0.55 30.80
md0 0.00 0.00 0.00 2201.60 0.00 543474.40 0.00 271737.20 246.85 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.40 0.00 553.00 0.00 136131.40 0.00 68065.70 246.17 0.88 1.60 0.45 25.04
sdc 0.00 0.40 0.00 552.80 0.00 136140.80 0.00 68070.40 246.27 0.99 1.79 0.44 24.08
sdd 0.00 0.00 0.00 547.80 0.00 136147.20 0.00 68073.60 248.53 1.12 2.05 0.56 30.72
sde 0.00 0.80 0.00 549.80 0.00 136028.80 0.00 68014.40 247.42 1.31 2.37 0.56 30.96
md0 0.00 0.00 0.00 2206.40 0.00 544779.40 0.00 272389.70 246.91 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 549.60 0.00 135710.60 0.00 67855.30 246.93 0.85 1.54 0.47 26.08
sdc 0.00 0.20 0.00 544.80 0.00 135724.20 0.00 67862.10 249.13 1.02 1.88 0.47 25.36
sdd 0.00 0.20 0.00 548.20 0.00 135739.20 0.00 67869.60 247.61 1.15 2.09 0.57 31.52
sde 0.00 2.00 0.00 553.80 0.00 135891.20 0.00 67945.60 245.38 1.24 2.25 0.56 31.28
md0 0.00 0.00 0.00 2197.40 0.00 542734.00 0.00 271367.00 246.99 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 553.60 0.00 135733.00 0.00 67866.50 245.18 0.84 1.53 0.47 25.76
sdc 0.00 0.20 0.00 545.00 0.00 135703.40 0.00 67851.70 249.00 1.02 1.87 0.46 24.96
sdd 0.00 0.40 0.00 548.60 0.00 135649.60 0.00 67824.80 247.27 1.13 2.06 0.56 30.72
sde 0.00 0.00 0.00 548.60 0.00 135673.60 0.00 67836.80 247.31 1.27 2.32 0.56 30.64
md0 0.00 0.00 0.00 2196.40 0.00 542759.60 0.00 271379.80 247.11 0.00 0.00 0.00 0.00
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.40 0.00 445.00 0.00 109865.80 0.00 54932.90 246.89 0.70 1.58 0.46 20.64
sdc 0.00 1.00 0.00 447.00 0.00 109896.20 0.00 54948.10 245.85 0.79 1.77 0.45 20.24
sdd 0.00 0.60 0.00 448.00 0.00 109880.60 0.00 54940.30 245.27 0.94 2.10 0.55 24.64
sde 0.00 0.40 0.00 441.80 0.00 109851.20 0.00 54925.60 248.64 1.07 2.43 0.56 24.64
md0 0.00 0.00 0.00 1784.20 0.00 439493.80 0.00 219746.90 246.33 0.00 0.00 0.00 0.00
and here's 'vmstat 5' during the same time, at 5 sec intervals:
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
1 0 596 867408 192 77884 0 0 2 1 1163 30 0 2 98 0
1 0 596 299956 196 628000 0 0 2 275379 21385 3112 0 58 36 5
1 0 596 92256 196 829024 0 0 0 276103 20903 3997 0 59 35 5
2 0 596 8320 100 909068 0 0 0 275221 20929 3106 0 61 35 5
1 0 596 8276 88 908564 0 0 0 275253 21041 2410 0 62 33 5
1 0 596 7100 88 909980 0 0 0 275288 21001 2243 0 63 33 4
1 0 596 7524 88 909356 0 0 0 274507 20956 2207 0 62 33 5
1 1 596 7520 88 909396 0 0 0 272799 20833 2236 0 63 33 4
1 0 596 7040 88 909936 0 0 0 271638 20771 2060 0 63 32 5
1 0 596 7996 88 909008 0 0 0 271984 20773 2191 0 63 32 5
1 0 596 7940 88 909084 0 0 0 271769 20755 2155 0 63 31 5
2 0 596 7824 88 908980 0 0 0 272193 20743 2158 0 63 32 5
1 0 596 7144 88 909812 0 0 0 271100 20736 2121 0 64 31 5