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Diffstat (limited to 'arch/m68k/mm/fault.c')
-rw-r--r--arch/m68k/mm/fault.c42
1 files changed, 34 insertions, 8 deletions
diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c
index 6b020a8..aeebbb7 100644
--- a/arch/m68k/mm/fault.c
+++ b/arch/m68k/mm/fault.c
@@ -72,7 +72,8 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
{
struct mm_struct *mm = current->mm;
struct vm_area_struct * vma;
- int write, fault;
+ int fault;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
#ifdef DEBUG
printk ("do page fault:\nregs->sr=%#x, regs->pc=%#lx, address=%#lx, %ld, %p\n",
@@ -87,6 +88,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
if (in_atomic() || !mm)
goto no_context;
+retry:
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
@@ -117,14 +119,13 @@ good_area:
#ifdef DEBUG
printk("do_page_fault: good_area\n");
#endif
- write = 0;
switch (error_code & 3) {
default: /* 3: write, present */
/* fall through */
case 2: /* write, not present */
if (!(vma->vm_flags & VM_WRITE))
goto acc_err;
- write++;
+ flags |= FAULT_FLAG_WRITE;
break;
case 1: /* read, present */
goto acc_err;
@@ -139,10 +140,14 @@ good_area:
* the fault.
*/
- fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0);
+ fault = handle_mm_fault(mm, vma, address, flags);
#ifdef DEBUG
printk("handle_mm_fault returns %d\n",fault);
#endif
+
+ if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+ return 0;
+
if (unlikely(fault & VM_FAULT_ERROR)) {
if (fault & VM_FAULT_OOM)
goto out_of_memory;
@@ -150,10 +155,31 @@ good_area:
goto bus_err;
BUG();
}
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
+
+ /*
+ * Major/minor page fault accounting is only done on the
+ * initial attempt. If we go through a retry, it is extremely
+ * likely that the page will be found in page cache at that point.
+ */
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (fault & VM_FAULT_MAJOR)
+ current->maj_flt++;
+ else
+ current->min_flt++;
+ if (fault & VM_FAULT_RETRY) {
+ /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
+ * of starvation. */
+ flags &= ~FAULT_FLAG_ALLOW_RETRY;
+
+ /*
+ * No need to up_read(&mm->mmap_sem) as we would
+ * have already released it in __lock_page_or_retry
+ * in mm/filemap.c.
+ */
+
+ goto retry;
+ }
+ }
up_read(&mm->mmap_sem);
return 0;