Am 08.10.2013 22:39, schrieb Dicebot:
On Tuesday, 8 October 2013 at 17:55:33 UTC, Araq wrote:
O(1) malloc implementations exist, it is a solved problem.
(http://www.gii.upv.es/tlsf/)
custom allocator != generic malloc
In such conditions you almost always want to use incremental region
allocator anyway. Problem is hidden automatical allocation.
TLSF executes a maximum of 168 processor instructions in a x86
architecture. Saying that you can't use that during request handling
is like saying that you can't afford a cache miss.
Some time ago I have been working in a networking project where request
context was specifically designed to fit in a single cache line and
breaking this immediately resulted in 30-40% performance penalty. There
is nothing crazy about saying you can't afford an extra cache miss. It
is just not that common. Same goes for avoiding heap allocations (but is
much more common).
How did you manage to keep the request size portable across
processors/motherboards?
Was the hardware design fixed?
--
Paulo
