Hugetlbfs file mappings are handled differently than regular files:
- pager_req_create will tell us the file is in a hugetlbfs
- allocate memory upfront, we need to fail if not enough memory
- the memory needs to be given again if another process maps the same
file
This implementation still has some hacks, in particular, the memory
needs to be freed when all mappings are done and the file has been
deleted/closed by all processes.
We cannot know when the file is closed/unlinked easily, so clean up
memory when all processes have exited.
To test, install libhugetlbfs and link a program with the additional
LDFLAGS += -B /usr/share/libhugetlbfs -Wl,--hugetlbfs-align
Then run with HUGETLB_ELFMAP=RW set, you can check this works with
HUGETLB_DEBUG=1 HUGETLB_VERBOSE=2
Change-Id: I327920ff06efd82e91b319b27319f41912169af1
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
