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add shared mapped file (in progress)

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implemented:
- Pages can be shared between maps.
- A change made to a map is written to the file, at munmap().

not yet implemented:
- VM operation during page IO execution.
  Because page IO is executed with VM's lock.
- Page IO, which does not change a file size with any case.
  When munmap() races with truncate(), the file size may be changed
  illegally.
This commit is contained in:
NAKAMURA Gou
2013-11-06 17:17:56 +09:00
parent d35140ab0b
commit bbbc6e1570
8 changed files with 153 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
arch/x86/kernel/memory.c
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@@ -814,6 +814,8 @@ static int split_large_page(pte_t *ptep)
struct clear_range_args {
int free_physical;
uint8_t padding[4];
struct memobj *memobj;
};
static int clear_range_l1(void *args0, pte_t *ptep, uint64_t base,
@@ -822,13 +824,18 @@ static int clear_range_l1(void *args0, pte_t *ptep, uint64_t base,
struct clear_range_args *args = args0;
uint64_t phys;
struct page *page;
pte_t old;
if (*ptep == PTE_NULL) {
return -ENOENT;
}
phys = *ptep & PT_PHYSMASK;
*ptep = PTE_NULL;
old = xchg(ptep, PTE_NULL);
if ((old & PFL1_DIRTY) && args->memobj) {
memobj_flush_page(args->memobj, phys, PTL1_SIZE);
}
if (args->free_physical) {
page = phys_to_page(phys);
@@ -848,6 +855,7 @@ static int clear_range_l2(void *args0, pte_t *ptep, uint64_t base,
struct page_table *pt;
int error;
struct page *page;
pte_t old;
if (*ptep == PTE_NULL) {
return -ENOENT;
@@ -869,7 +877,11 @@ static int clear_range_l2(void *args0, pte_t *ptep, uint64_t base,
if (*ptep & PFL2_SIZE) {
phys = *ptep & PT_PHYSMASK;
*ptep = PTE_NULL;
old = xchg(ptep, PTE_NULL);
if ((old & PFL2_DIRTY) && args->memobj) {
memobj_flush_page(args->memobj, phys, PTL2_SIZE);
}
if (args->free_physical) {
page = phys_to_page(phys);
@@ -922,7 +934,7 @@ static int clear_range_l4(void *args0, pte_t *ptep, uint64_t base,
}
static int clear_range(struct page_table *pt, uintptr_t start, uintptr_t end,
int free_physical)
int free_physical, struct memobj *memobj)
{
int error;
struct clear_range_args args;
@@ -935,6 +947,8 @@ static int clear_range(struct page_table *pt, uintptr_t start, uintptr_t end,
}
args.free_physical = free_physical;
args.memobj = memobj;
error = walk_pte_l4(pt, 0, start, end, &clear_range_l4, &args);
return error;
}
@@ -943,14 +957,14 @@ int ihk_mc_pt_clear_range(page_table_t pt, void *start, void *end)
{
#define KEEP_PHYSICAL 0
return clear_range(pt, (uintptr_t)start, (uintptr_t)end,
KEEP_PHYSICAL);
KEEP_PHYSICAL, NULL);
}
int ihk_mc_pt_free_range(page_table_t pt, void *start, void *end)
int ihk_mc_pt_free_range(page_table_t pt, void *start, void *end, struct memobj *memobj)
{
#define FREE_PHYSICAL 1
return clear_range(pt, (uintptr_t)start, (uintptr_t)end,
FREE_PHYSICAL);
FREE_PHYSICAL, memobj);
}
struct change_attr_args {
@@ -1284,7 +1298,7 @@ int set_range_l1(void *args0, pte_t *ptep, uintptr_t base, uintptr_t start,
error = -EBUSY;
ekprintf("set_range_l1(%lx,%lx,%lx):page exists. %d %lx\n",
base, start, end, error, *ptep);
(void)clear_range(args->pt, start, base, KEEP_PHYSICAL);
(void)clear_range(args->pt, start, base, KEEP_PHYSICAL, NULL);
goto out;
}
@@ -1332,7 +1346,7 @@ int set_range_l2(void *args0, pte_t *ptep, uintptr_t base, uintptr_t start,
"__alloc_new_pt failed. %d %lx\n",
base, start, end, error, *ptep);
(void)clear_range(args->pt, start, base,
KEEP_PHYSICAL);
KEEP_PHYSICAL, NULL);
goto out;
}
@@ -1343,7 +1357,7 @@ int set_range_l2(void *args0, pte_t *ptep, uintptr_t base, uintptr_t start,
ekprintf("set_range_l2(%lx,%lx,%lx):"
"page exists. %d %lx\n",
base, start, end, error, *ptep);
(void)clear_range(args->pt, start, base, KEEP_PHYSICAL);
(void)clear_range(args->pt, start, base, KEEP_PHYSICAL, NULL);
goto out;
}
else {
@@ -1400,7 +1414,7 @@ int set_range_l3(void *args0, pte_t *ptep, uintptr_t base, uintptr_t start,
"__alloc_new_pt failed. %d %lx\n",
base, start, end, error, *ptep);
(void)clear_range(args->pt, start, base,
KEEP_PHYSICAL);
KEEP_PHYSICAL, NULL);
goto out;
}
*ptep = virt_to_phys(pt) | PFL3_PDIR_ATTR;
@@ -1410,7 +1424,7 @@ int set_range_l3(void *args0, pte_t *ptep, uintptr_t base, uintptr_t start,
ekprintf("set_range_l3(%lx,%lx,%lx):"
"page exists. %d %lx\n",
base, start, end, error, *ptep);
(void)clear_range(args->pt, start, base, KEEP_PHYSICAL);
(void)clear_range(args->pt, start, base, KEEP_PHYSICAL, NULL);
goto out;
}
else {
@@ -1449,7 +1463,7 @@ int set_range_l4(void *args0, pte_t *ptep, uintptr_t base, uintptr_t start,
"__alloc_new_pt failed. %d %lx\n",
base, start, end, error, *ptep);
(void)clear_range(args->pt, start, base,
KEEP_PHYSICAL);
KEEP_PHYSICAL, NULL);
goto out;
}
*ptep = virt_to_phys(pt) | PFL4_PDIR_ATTR;