[PATCH 0/4] 8xx: Optimize TLB Miss code.

[Joakim Tjernlund]

Heiko Schocher <hs at denx.de> wrote on 2010/03/03 11:10:10:
>
> Hello Joakim,
>
> Joakim Tjernlund wrote:
> > Heiko Schocher <hs at denx.de> wrote on 2010/03/03 09:02:47:
> [...]
> >> Here the results:
> >> (The first 4 rows are the results for the kernel without your patches,
> >>  the next 4 rows are the results for the kernel with your patches)
> >>
> >> make[1]: Entering directory `/home/hs/lmbench-3.0-a9/results'
> >
> > I see both ups and downs in this test, don't quite understand why.
> > What is your config w.r.t SWAP, MODULES, CPU6 and CPU15?
>
> Sorry, forgot to say, where to find the sources. You can find them
> here:
>
> http://git.denx.de/?p=linux-2.6-denx.git;a=shortlog;h=refs/heads/tqm8xx

OK, so you got SWAP=no, MODULES=yes, CPU6=no, CPU15=no
PIN_TLB isn't listed in you def config so I assume
it is no?

MODULES=yes nullifies one optimization.

I don't understand the bad numbers for Prot Fault:
File & VM system latencies in microseconds - smaller is better
-------------------------------------------------------------------------------
Host                 OS   0K File      10K File     Mmap    Prot   Page   100fd
                        Create Delete Create Delete Latency Fault  Fault  selct
--------- ------------- ------ ------ ------ ------ ------- ----- ------- -----
tqm8xx    Linux 2.6.33- 5917.2 3968.3  31.2K 4329.0  4147.0  18.8    34.1 135.2
tqm8xx    Linux 2.6.33- 5714.3 3937.0  32.3K 6060.6  4210.0  14.2    34.5 131.4
tqm8xx    Linux 2.6.33- 5747.1 4000.0  31.2K 4329.0  4114.0 7.692    34.0 133.1
tqm8xx    Linux 2.6.33- 5747.1 4081.6  30.3K 4273.5  4100.0  18.2    34.2 135.0
tqm8xx    Linux 2.6.33- 5714.3 3952.6  31.2K 4273.5  4130.0  33.5    35.1 136.1
tqm8xx    Linux 2.6.33- 5714.3 3906.2  31.2K 6060.6  4105.0  25.7    35.5 135.9
tqm8xx    Linux 2.6.33- 5681.8 3921.6  32.3K 4255.3  4144.0  23.5    35.0 134.9
tqm8xx    Linux 2.6.33- 5649.7 3937.0  30.3K 4237.3  4116.0  21.6    35.3 135.3

Could you try reverting patch:
  8xx: Don't touch ACCESSED when no SWAP.
and see if that makes a difference?

Turning on pinned TLBs(you must turn on ADVANCED_OPTIONS first) could be an improvement,
regardless of my patches.

    Jocke