Re: finish_task_switch high in profiles in 2.6.7

Yusuf Goolamabbas
2004-06-24T09:34:46Z

> Is it an SMP system? What sort of workload is it? Does it use threads?
> Check vmstat to see how much context switching is going on with each
> kernel.

Yes, It's an SMP (Dual P3-800). Workload is a busy mailserver (get lots
of SMTP traffic, validate users against a remote database, reject a
truckload of connections). CONFIG_4K_STACKS=y on the 2.6.7 box, e100
driver with NAPI turned off. No threads

The 2.6.7 box shows this wrt context swithes

procs memory swap io system cpu
r b swpd free buff cache si so bi bo in cs us sy wa id
3 0 0 73096 63000 78100 0 0 0 524 5571 14772 25 73 0 2
6 0 0 70932 63000 78100 0 0 0 448 5861 11368 34 65 0 1
7 0 0 72916 63008 78092 0 0 0 12 5838 14956 30 70 0 1
7 0 0 70852 63016 78084 0 0 0 1008 5551 13951 30 69 0 1
22 0 0 65300 63016 78084 0 0 0 0 5989 16043 34 66 0 1
19 0 0 66516 63020 78148 0 0 0 1252 6100 14653 31 69 0 0
29 1 0 67620 63024 78212 0 0 0 992 6314 14747 31 69 0 0

The 2.6.5 box shows this

procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
166 0 0 137752 38148 188836 0 0 0 2424 5973 21695 30 70 0 0
34 0 0 135928 38160 189028 0 0 0 2160 5923 22532 32 68 0 0
28 1 0 136928 38184 189344 0 0 0 2904 6393 22098 31 69 0 0
32 1 0 136672 38204 189324 0 0 0 3240 6412 21362 32 68 0 0
33 0 0 135456 38216 189380 0 0 0 1708 6044 24735 28 72 0 0
17 0 0 135372 38264 189536 0 0 0 3044 6305 22326 35 64 0 0
229 0 0 135060 38272 189732 0 0 0 2340 6416 23697 33 67 0 0 32 0 0 134100 38288 189852 0 0 0 3068 6342 24016 33 67 0 0
16 0 0 134292 38300 190044 0 0 0 2408 6451 24727 31 69 0 0