On Fri, 7 Jan 2005, Rasmus Lerdorf wrote: > I still think it would be worthwhile to make it configurable. Linux or > FreeBSD5 on IA64 with 16k pages, for example, might show some decent > gains by setting that to 15000. Or do a getpagesize() call on startup > to determine it dynamically.
It might be. We've considered having it be configurable before. There are just a lot of implications in changing the value; for example, it affects the memory footprint of the server, it affects how much data gets read in to memory per read() call on a file bucket (which might alter the decision of whether read() or mmap() is preferable, for example), it affects how well the data fits into memory pages, and it affects how much data is buffered in one block for the scenarios you described. There are probably others I'm not thinking of right now, too. Lots of different axes that must be considered when trying to pick an optimal value. But still, if you want to make it configurable, go right ahead. :)
