jffs zlib tuning

[Bernardo Innocenti]

(cc CP, aleph)

David Woodhouse wrote:

>> 1. Did anybody profile the kernel while reading files? Last thing I red 
>> on this list is that the profiler does not work on the XO in kernel 
>> mode. Did anybody fix that
> 
> I believe that standard kernel profiling (on timer ticks) has always
> worked, and even continues to work even though we use a tickless kernel
> now. I think oprofile also works.

oprofile works, but for some reason it cannot generate
call graphs.

It vaguely remember that the problem was that on the Geode we
were using sw timers rather than NMI as a timing source.

Without call graphs, benchmarking our rendering stack has been
somewhat harder.  You'd find lots of time spent in generic
functions such as memcpy(), without a clue why.

-- 
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 |___|   Bernardo Innocenti - http://www.codewiz.org/
  \___\  One Laptop Per Child - http://www.laptop.org/