Hi Ibe (learnedbyerror)!

Thanks for your informative response!
I think that we are "on the same page" and you know what you are doing!

You are quite correct to be suspicious of gcc -O3 level. I TA an Advanced Assembly class whenever it "makes", which is only about every 5 years. It is a difficult class and it takes years to get enough qualified students in order to justify running the class.

Sometimes we play "beat the compiler". This is possible at even at the highest optimization level. I agree that -O2 is "fairly safe". At -O3 the compiler gets increasingly bizarre in what it does - it writes ASM that no human would ever think of. It may even write code that winds up slower! The Phd guy I alluded to in an earlier post was one of our students.

Here is one suggestion which may or may not help you:

Your application is very DB intensive.
The DB will have two important general limits:

  1. the number of operations per second
  2. a much smaller number, the number of transactions per second
As it turns out, the commit of 1 million inserts doesn't take much longer than the commit of just one single insert.

See if you can reduce the number of DB transactions per second. This can have a huge impact upon performance! You may or may not be done with the first part of optimization (algorithm and coding enhancements).

I suspect that there is still more than a 25% improvement that can be had without resorting to an optimized compile of Perl itself.

In reply to Re^3: Compile perl for performance by Marshall
in thread Compile perl for performance by learnedbyerror

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