Using an edata_t both for hugepages and the allocations within those hugepages
was convenient at first, but has outlived its usefulness. Representing
hugepages explicitly, with their own data structure, will make future
development easier.
This was promised in the review of the introduction of geom_grow, but would have
been painful to do there because of the series that introduced it. Now that
those are comitted, renaming is easier.
Previously all the small size classes were cached. However this has downsides
-- particularly when page size is greater than 4K (e.g. iOS), which will result
in much higher SMALL_MAXCLASS.
This change allows tcache_max to be set to lower values, to better control
resources taken by tcache.
This will be the centralized component of the coming hugepage allocator; the
source of larger chunks of memory from which smaller ones can be obtained.
This introduces a new sort of edata_t; a pageslab, and a set to manage them.
This is part of a series of a commits to implement a hugepage allocator; the
pageset will be per-arena, and track small page allocations requests within a
larger extent allocated from a centralized hugepage allocator.
The existing checks are good at finding such issues (on tcache flush), but not
so good at pinpointing them. Debug mode can find them, but sometimes debug mode
slows down a program so much that hard-to-hit bugs can take a long time to
crash.
This commit adds functionality to keep programs mostly on their fast paths,
while also checking every sized delete argument they get.
Add options stats_interval and stats_interval_opts to allow interval based stats
printing. This provides an easy way to collect stats without code changes,
because opt.stats_print may not work (some binaries never exit).
Eventually, we may fully break off the extent module; but not for some time. If
it's going to live on in a non-transitory state, it might as well have the nicer
name.
This will eventually completely wrap the eset, and handle concurrency,
allocation, and deallocation. For now, we only pull out the mutex from the
eset.
