Re: [eigen] Clean aligned memory allocation

[Gael Guennebaud <gael.guennebaud@xxxxxxxxx>]

Maybe I should precise that the previous numbers have been obtained on OSX. On Linux I observe nearly no overhead at all for our handmade version.

For completeness, I attached some interesting plots comparing posix_memalign vs handmade_aligned_alloc, on both linux and osx, for allocating 100 buffers of sizes going from 4 to 16000 Bytes with an increment of 4 Bytes.

Despite the overhead on OSX for some particular buffer size, I'm still in favor of keeping the std::malloc based variants only, mainly because of the huge performance impact of reallocating a buffer allocated with posix_memalign.

gael

Attachment: mem_overhead_linux.pdf
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Attachment: mem_overhead_osx.pdf
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