[andreer]

The reason is simply, for performance. To avoid having to go to the kernel every time we need to allocate memory for a query, and avoid having to clear memory on free/reuse. It is made for Vespa, but also used for other programs.

Similar in purpose to Google's TCMalloc: http://goog-perftools.sourceforge.net/doc/tcmalloc.html

[sanxiyn]

How is it better than TCMalloc? (If it isn't, it probably should be replaced by TCMalloc.)

[andreer]

In our tests, vespamalloc has simply been faster. I don't know how in-depth the analysis has been as to why, but obviously vespamalloc is written and tuned for Vespa so that is a likely factor.