Re: finish_task_switch high in profiles in 2.6.7

[Nick Piggin]

Yusuf Goolamabbas wrote:
> > 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 

OK

> 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

OK. They're both using 100% CPU... is 2.6.5 getting more work done?
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