With the Gentoo benchmark, I was wondering if a full test could be done comparing the performance between a kernel with CONFIG_CC_OPTIMIZE_FOR_SIZE=y and one with CONFIG_CC_OPTIMIZE_FOR_SIZE=n.
There have been myths whether throughput increases by building the kernel for size as CPUs with small L2 cache banks would benefit from the reduced executable code, but the code itself should be less optimized in general. Linus himself suggests that optimize for size should be used unless your application uses MMX or floating points -> http://gcc.gnu.org/ml/gcc/2001-07/msg01543.html
If L2 thrashing can be reduced by building with -Os, wouldn't user space applications in general execute faster?
There have been myths whether throughput increases by building the kernel for size as CPUs with small L2 cache banks would benefit from the reduced executable code, but the code itself should be less optimized in general. Linus himself suggests that optimize for size should be used unless your application uses MMX or floating points -> http://gcc.gnu.org/ml/gcc/2001-07/msg01543.html
If L2 thrashing can be reduced by building with -Os, wouldn't user space applications in general execute faster?
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