The gencore() and freecore() code in gencore.c is guarded by
POSTK_DEBUG_ARCH_DEP_18, so the call to these functions should
also be guarded, otherwise linking fails.
Previously the allocator would return all availble memory for a
request of 0 pages. This is rather counter-intuitive and left no
memory for subsequent allocations.
There is no good reason to map these low addresses (userspace could with
mmap fixed, but that is grounds for many exploits...);
the main advantage however is if we do a null deref or close to (0->foo)
within a pagefault we will get a panic stack instead of getting a hang
because we cannot get some locks.
This replaces the chained list used to keep track of all memory ranges
of a process by a standard rbtree (no need of interval tree here
because there is no overlap)
Accesses that were done directly through vm_range_list before were
replaced by lookup_process_memory_range, even full list scan (e.g.
coredump).
The full scans will thus be less efficient because calls to rb_next()
will not be inlined, but these are rarer calls that can probably afford
this compared to code simplicity.
The only reference to the actual backing structure left outside of
process.c is a call to rb_erase in xpmem_free_process_memory_range.
v2: fix lookup_process_memory_range with small start address
v3: make vm_range_insert error out properly
Panic does not lead to easy debug, all error paths
are handled to just return someting on error
v4: fix lookup_process_memory_range (again)
That optimistically going left was a more serious bug than just
last iteration, we could just pass by a match and continue down
the tree if the match was not a leaf.
v5: some users actually needed leftmost match, so restore behavior
without the breakage (hopefully)
1. Fix OOM: Count memory usage only when allocation succeeded
2. Fix OOM: Make user allocation fail when memory is running out
3. Fix OOM: Move rusage_init() before numa_init()
4. Cleanup: Rename ihkconfig/ihkosctl functions
5. Cleanup: Pass event type to eventfd()
6. Cleanup: arch/.../rusage.h --> arch/.../arch_rusage.h
1. User asks mcctrl for the result via ihk_os_getrusage() with passing void *
2. mcctrl compiles the results and passes them to the user
3. User interprets it by using the type defined in the LWK-specific header
