This adds the ability for a Region to define volatile/nonvolatile
areas within mapped memory using madvise(). This also means that
memory purging takes into account all views of the PurgeableVMObject
and only purges memory that is not needed by all of them. When calling
madvise() to change an area to nonvolatile memory, return whether
memory from that area was purged. At that time also try to remap
all memory that is requested to be nonvolatile, and if insufficient
pages are available notify the caller of that fact.
The SI prefixes "k", "M", "G" mean "10^3", "10^6", "10^9".
The IEC prefixes "Ki", "Mi", "Gi" mean "2^10", "2^20", "2^30".
Let's use the correct name, at least in code.
Only changes the name of the constants, no other behavior change.
By having a separate list of constructors for the kernel heap
code, we can properly use constructors without re-running them
after the heap was already initialized. This solves some problems
where values were wiped out because they were overwritten by
running their constructors later in the initialization process.
We need to be able to prevent a WaitQueue from being
modified by another CPU. So, add a SpinLock to it.
Because this pushes some other class over the 64 byte
limit, we also need to add another 128-byte bucket to
the slab allocator.
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
Now that the kernel supports startup-time constructors, we were first
doing slab_alloc_init(), and then the constructors ran later on,
zeroing out the freelist pointers.
This meant that all slab allocators thought they were completelty
exhausted and forwarded all requests to kmalloc() instead.
This is obviously not ideal, and it would be better to teach it how to
allocate more pages, etc. But since the physical page allocator itself
currently uses SlabAllocator, it's a little bit tricky :^)
We need these for PhysicalPage objects. Ultimately I'd like to get rid
of these objects entirely, but while we still have to deal with them,
let's at least handle large demand a bit better.
This is a freelist allocator with static size classes that works as a
complement to the generic kmalloc(). It's a lot faster than kmalloc()
since allocation just means popping from the freelist.
It's also significantly more compact when there are a lot of objects
smaller than the minimum kmalloc chunk size (32 bytes.)
This patch enables it for the Region and PhysicalPage classes.
In the PhysicalPage (8 bytes) case, it's a huge improvement since we
no longer waste 75% of the storage allocated.
There are also a number of ways this can be improved, so let's keep
working on it going forward.
