Changeset 5f7a0ef in mainline for kernel/generic/src/mm/frame.c

Timestamp:

2008-07-06T19:47:48Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

498b201

Parents:

2ec725f

Message:

Introduce FRAME_LOW_16_GiB slab/frame allocator flag. When specified, the
allocators will not allocate memory above 16 GiB. Each architecture needs to
make sure not to merge zones from below and above 16 GiB. Allocations that
require memory below 16 GiB need to be altered to use this flag.

File:

• kernel/generic/src/mm/frame.c (modified) (8 diffs)

kernel/generic/src/mm/frame.c

@@ -201 +201 @@
 }
 
-/**
- * Try to find a zone where can we find the frame.
+/** Try to find a zone where can we find the frame.
  *
  * Assume interrupts are disabled.
@@ -238 +237 @@
                 if (i >= zones.count)
                         i = 0;
-        } while(i != hint);
+        } while (i != hint);
 
         spinlock_unlock(&zones.lock);
@@ -255 +254 @@
  *
  * @param order         Size (2^order) of free space we are trying to find.
+ * @param flags         Required flags of the target zone.
  * @param pzone         Pointer to preferred zone or NULL, on return contains
  *                      zone number.
  */
-static zone_t *find_free_zone_and_lock(uint8_t order, unsigned int *pzone)
+static zone_t *
+find_free_zone_and_lock(uint8_t order, int flags, unsigned int *pzone)
 {
         unsigned int i;
@@ -264 +265 @@
         unsigned int hint = pzone ? *pzone : 0;
         
+        /* Mask off flags that are not applicable. */
+        flags &= FRAME_LOW_16_GiB;
+
         spinlock_lock(&zones.lock);
         if (hint >= zones.count)
@@ -273 +277 @@
                 spinlock_lock(&z->lock);
 
-                /* Check if the zone has 2^order frames area available  */
-                if (zone_can_alloc(z, order)) {
-                        spinlock_unlock(&zones.lock);
-                        if (pzone)
-                                *pzone = i;
-                        return z;
+                /*
+                 * Check whether the zone meets the search criteria.
+                 */
+                if ((z->flags & flags) == flags) {
+                        /*
+                         * Check if the zone has 2^order frames area available.
+                         */
+                        if (zone_can_alloc(z, order)) {
+                                spinlock_unlock(&zones.lock);
+                                if (pzone)
+                                        *pzone = i;
+                                return z;
+                        }
                 }
                 spinlock_unlock(&z->lock);
                 if (++i >= zones.count)
                         i = 0;
-        } while(i != hint);
+        } while (i != hint);
         spinlock_unlock(&zones.lock);
         return NULL;
@@ -811 +822 @@
         z->base = start;
         z->count = count;
+
+        /* Mask off flags that are calculated automatically. */
+        flags &= ~FRAME_LOW_16_GiB;
+        /* Determine calculated flags. */
+        if (z->base + count < (1ULL << (34 - FRAME_WIDTH)))     /* 16 GiB */
+                flags |= FRAME_LOW_16_GiB;
+
         z->flags = flags;
+
         z->free_count = count;
         z->busy_count = 0;
@@ -983 +1002 @@
          * First, find suitable frame zone.
          */
-        zone = find_free_zone_and_lock(order, pzone);
+        zone = find_free_zone_and_lock(order, flags, pzone);
         
         /* If no memory, reclaim some slab memory,
@@ -990 +1009 @@
                 freed = slab_reclaim(0);
                 if (freed)
-                        zone = find_free_zone_and_lock(order, pzone);
+                        zone = find_free_zone_and_lock(order, flags, pzone);
                 if (!zone) {
                         freed = slab_reclaim(SLAB_RECLAIM_ALL);
                         if (freed)
-                                zone = find_free_zone_and_lock(order, pzone);
+                                zone = find_free_zone_and_lock(order, flags,
+                                    pzone);
                 }
         }