Changeset 4ed41b3 in mainline

Timestamp:

2018-02-20T11:07:51Z (6 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

a211838

Parents:

fec0240

Message:

use a dedicated cache for the per-CPU magazines of caches

This avoids using the malloc()/free() API within the SLAB allocator
itself (which was slightly inconsistent) and it should also conserve
memory since the cache for the per-CPU magazines is sized precisely
according to the number of CPUs.

File:

• kernel/generic/src/mm/slab.c (modified) (6 diffs)

kernel/generic/src/mm/slab.c

@@ -125 +125 @@
 /** Cache for cache descriptors */
 static slab_cache_t slab_cache_cache;
+
+/** Cache for per-CPU magazines of caches */
+static slab_cache_t slab_mag_cache;
 
 /** Cache for external slab descriptors
@@ -589 +592 @@
         assert(_slab_initialized >= 2);
         
-        cache->mag_cache = malloc(sizeof(slab_mag_cache_t) * config.cpu_count,
-            FRAME_ATOMIC);
+        cache->mag_cache = slab_alloc(&slab_mag_cache, FRAME_ATOMIC);
         if (!cache->mag_cache)
                 return false;
@@ -723 +725 @@
 }
 
+/** Return object to cache, use slab if known
+ *
+ */
+NO_TRACE static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
+{
+        ipl_t ipl = interrupts_disable();
+        
+        if ((cache->flags & SLAB_CACHE_NOMAGAZINE) ||
+            (magazine_obj_put(cache, obj)))
+                slab_obj_destroy(cache, obj, slab);
+        
+        interrupts_restore(ipl);
+        atomic_dec(&cache->allocated_objs);
+}
+
 /** Check that there are no slabs and remove cache from system
  *
@@ -751 +768 @@
                 panic("Destroying cache that is not empty.");
         
-        if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
-                free(cache->mag_cache);
+        if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
+                slab_t *mag_slab = obj2slab(cache->mag_cache);
+                _slab_free(mag_slab->cache, cache->mag_cache, mag_slab);
+        }
         
         slab_free(&slab_cache_cache, cache);
@@ -779 +798 @@
         
         return result;
-}
-
-/** Return object to cache, use slab if known
- *
- */
-NO_TRACE static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
-{
-        ipl_t ipl = interrupts_disable();
-        
-        if ((cache->flags & SLAB_CACHE_NOMAGAZINE) ||
-            (magazine_obj_put(cache, obj)))
-                slab_obj_destroy(cache, obj, slab);
-        
-        interrupts_restore(ipl);
-        atomic_dec(&cache->allocated_objs);
 }
 
@@ -931 +935 @@
 #endif
         
+        _slab_cache_create(&slab_mag_cache, "slab_mag_cache",
+            sizeof(slab_mag_cache_t) * config.cpu_count, sizeof(uintptr_t),
+            NULL, NULL, SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
+        
         irq_spinlock_lock(&slab_cache_lock, false);