Access nactive, ndirty and nmuzzy throught getters and not directly.
There are no functional change, but getters are required to propagate
HPA's statistics up to Page Allocator's statitics.
- `-Wmissing-prototypes` and `-Wmissing-variable-declarations` are
helpful for finding dead code and/or things that should be `static`
but aren't marked as such.
- `-Wunused-macros` is of similar utility, but for identifying dead macros.
- `-Wunreachable-code` and `-Wunreachable-code-aggressive` do exactly
what they say: flag unreachable code.
For better or worse, Jemalloc has a significant number of global
variables. Making all eligible global variables `static` and/or `const`
at least makes it slightly easier to reason about them, as these
qualifications communicate to the programmer restrictions on their use
without having to `grep` the whole codebase.
It appears that this was a simple mistake where `hpa_shard_disable` was
being called instead of `hpa_shard_destroy`. At present
`hpa_shard_destroy` is not called anywhere at all outside of test-cases,
which further suggests that this is a bug. @davidtgoldblatt noted
however that since HPA is disabled for manual arenas and we don't
support destruction for auto arenas that presently there is no way to
actually trigger this bug. Nonetheless, it should be fixed.
Currently used only for guarding purposes, the hint is used to determine
if the allocation is supposed to be frequently reused. For example, it
might urge the allocator to ensure the allocation is cached.
As the code evolves, some code paths that have previously assigned
deferred_work_generated may cease being reached. This would leave the value
uninitialized. This change initializes the value for safety.
Adding guarded extents, which are regular extents surrounded by guard pages
(mprotected). To reduce syscalls, small guarded extents are cached as a
separate eset in ecache, and decay through the dirty / muzzy / retained pipeline
as usual.
This change allows every allocator conforming to PAI communicate that it
deferred some work for the future. Without it if a background thread goes into
indefinite sleep, there is no way to notify it about upcoming deferred work.
Previously the calculation of sleep time between wakeups was implemented within
background_thread. This resulted in some parts of decay and hpa specific
logic mixing with background thread implementation. In this change, background
thread delegates this calculation to arena and it, in turn, delegates it to PAI.
The next step is to implement the actual calculation of time until deferred work
in HPA.
This change pulls the SEC options into a struct, which simplifies their handling
across various modules (e.g. PA needs to forward on SEC options from the
malloc_conf string, but it doesn't really need to know their names). While
we're here, make some of the fixed constants configurable, and unify naming from
the configuration options to the internals.
Currently that just means max_alloc, but we're about to add more. While we're
touching these lines anyways, tweak things to be more in line with testing.
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.
For now, this is just a stub containing the ecaches, with no surrounding code
changed. Eventually all the core allocator bits will be moved in, in the
subsequent stack of commits.
Now that we've moved junking to a higher level of the allocation stack, we don't
care about this performance optimization (which only occurred in debug modes).
