gh0s7/mckernel
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Handle hugetlbfs file mapping

Browse Source 
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
This commit is contained in:
Dominique Martinet
2018-09-21 10:50:31 +09:00
committed by Masamichi Takagi
parent 3e3ccf377c
commit 39f9d7fdff
14 changed files with 555 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
kernel/include/memobj.h
View File

@@ -19,6 +19,7 @@
#include <ihk/lock.h>
#include <errno.h>
#include <list.h>
#include <pager.h>
#ifdef POSTK_DEBUG_ARCH_DEP_18 /* coredump arch separation. */
#else /* POSTK_DEBUG_ARCH_DEP_18 */
@@ -44,6 +45,7 @@ enum {
MF_XPMEM = 0x10000, /* To identify XPMEM attachment pages for rusage accounting */
MF_ZEROOBJ = 0x20000, /* To identify pages of anonymous, on-demand paging ranges for rusage accounting */
MF_SHM = 0x40000,
MF_HUGETLBFS = 0x100000,
};
#define MEMOBJ_READY 0
@@ -83,11 +85,15 @@ static inline int memobj_ref(struct memobj *obj)
return ihk_atomic_inc_return(&obj->refcnt);
}
static inline void memobj_unref(struct memobj *obj)
static inline int memobj_unref(struct memobj *obj)
{
if (ihk_atomic_dec_return(&obj->refcnt) == 0) {
int cnt;
if ((cnt = ihk_atomic_dec_return(&obj->refcnt)) == 0) {
(*obj->ops->free)(obj);
}
return cnt;
}
static inline int memobj_get_page(struct memobj *obj, off_t off,
@@ -150,5 +156,10 @@ int shmobj_create(struct shmid_ds *ds, struct memobj **objp);
int zeroobj_create(struct memobj **objp);
int devobj_create(int fd, size_t len, off_t off, struct memobj **objp, int *maxprotp,
int prot, int populate_flags);
int hugefileobj_pre_create(struct pager_create_result *result,
struct memobj **objp, int *maxprotp);
int hugefileobj_create(struct memobj *obj, size_t len, off_t off,
int *pgshiftp, uintptr_t virt_addr);
void hugefileobj_cleanup(void);
#endif /* HEADER_MEMOBJ_H */