It has come to light that the chunked allocator have a couple of fundamental design issues.
The primary is that free space management becomes overly complex, causing significant performance issues. The second is that you can not really disable the use of pools by configuration, even if we claim this in squid.conf. The only way to control this runtime is by setting the undocumented(?) MEMPOOLS environment variable or by running under valgrind. I suspect the main effect of trying to disable or tune down usage of pools via squid.conf today is only significantly worsened performance. As I see it we basically have two choices a) Remove the memory pools config parameters from MemPools & squid.conf + related "impossible" free space reclaim code. b) Revert to the older much simpler pooled design. The main benefit of the chunked allocator is that it can pack data more efficiently than malloc() taking benefit of our typed allocations. In terms of fragmentation reduction there is very limited benefits And there is obvious drawbacks in free space reclaim efficiency. Regards Henrik
