Nick, As reported to you elsewhere (and duplicated here to get on this thread), application of the patch you sent (attached) dramatically changes the swappiness behavior of the 2.6.9-rc1 (and presumably the rc2) kernel. Here are the updated results: Previously: Kernel Version 2.6.9-rc1-mm3: Total I/O Avg Swap min max pg cache min max ----------- --------- ------- ------ --------- ------- ------- 0 274.80 MB/s 10511 MB ( 5644, 14492) 13293 MB ( 8596, 17156) 20 267.02 MB/s 12624 MB ( 5578, 16287) 15298 MB ( 8468, 18889) 40 267.66 MB/s 13541 MB ( 6619, 17461) 16199 MB ( 9393, 20044) 60 233.73 MB/s 18094 MB ( 16550, 19676) 20629 MB ( 19103, 22192) 80 213.64 MB/s 20950 MB ( 15844, 22977) 23450 MB ( 18496, 25440) 100 164.58 MB/s 26004 MB ( 26004, 26004) 28410 MB ( 28327, 28455) With Nick Piggin et al fix: Kernel Version: linux-2.6.9-rc1-mm3-kswapdfix Total I/O Avg Swap min max pg cache min max ----------- --------- ------- ------ --------- ------- ------- 0 279.97 MB/s 89 MB ( 12, 265) 3062 MB ( 2947, 3267) 20 283.55 MB/s 161 MB ( 15, 372) 3190 MB ( 3011, 3427) 40 282.32 MB/s 204 MB ( 6, 407) 3187 MB ( 2995, 3331) 60 279.42 MB/s 72 MB ( 15, 171) 3091 MB ( 3027, 3155) 80 283.34 MB/s 920 MB ( 144, 3028) 3904 MB ( 3106, 5957) 100 160.55 MB/s 26008 MB ( 26007, 26008) 28473 MB ( 28455, 28487) (The drop at swappiness of 60 may just be randomness, not sure it is significant, but these results are all based on 5 trials.) At any rate, this patch appears to fix the problems I was seeing before. (See http://marc.theaimsgroup.com/?l=linux-kernel&m=109449778320333&w=2 for further details of the benchmark and the test environment). -- Best Regards, Ray ----------------------------------------------- Ray Bryant 512-453-9679 (work) 512-507-7807 (cell) raybry@sgi.com raybry@austin.rr.com The box said: "Requires Windows 98 or better", so I installed Linux. -----------------------------------------------