[PD] symbol anxiety

Mathieu Bouchard matju at artengine.ca
Mon Feb 23 20:12:38 CET 2009

On Mon, 23 Feb 2009, Phil Stone wrote:

> Just to see the magnitude of the issue, I made a little test patch 
> (attached) called [symbol_pig].  It just creates symbols, very fast.  A 
> very rough measurement based on watching resident memory increasing in 
> bash's top command indicates that (on OS X 10.4), a megabyte is used up 
> for approximately every 32,000 symbols.

Each t_symbol is a 12-byte malloc (double that in 64-bit mode) and another 
malloc the size of the text plus one. Malloc overhead varies (as I said in 
the previous mail), but if you add 4 bytes and round to the next multiple 
of 16, that's almost the least RAM a malloc-function can use up for your 
malloc. So, 16+16=32 bytes per small symbol, that makes a megabyte.

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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal, Québec

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