(pager_offer_page): Only flush page if not in core now.

1 files changed, 14 insertions, 1 deletions

diff --git a/libpager/offer-page.c b/libpager/offer-page.c
index 42706929..0d16a418 100644
--- a/libpager/offer-page.c
+++ b/libpager/offer-page.c
@@ -28,11 +28,24 @@ pager_offer_page (struct pager *p,
 		  vm_offset_t offset,
 		  vm_address_t buf)
 {
+  char *pm_entry;
+  
   /* The caller expects this to get written back, but if the page is 
      currently resident then our request will get ignored, so flush it
      first */
   if (precious)
-    pager_flush_some (p, offset, vm_page_size, 1);
+    {
+      mutex_lock (&p->interlock);
+      _pager_pagemap_resize (p, offset + vm_page_size);
+      pm_entry = &p->pagemap[offset / vm_page_size];
+      if (*pm_entry & PM_INCORE)
+	{
+	  mutex_unlock (&p->interlock);
+	  pager_flush_some (p, offset, vm_page_size, 1);
+	}
+      else
+	mutex_unlock (&p->interlock);
+    }
 
   memory_object_data_supply (p->memobjcntl, offset, buf, vm_page_size, 0,
 			     writelock ? VM_PROT_WRITE : VM_PROT_NONE,