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6138 don't abuse atomic_cas_*

@@ -66,11 +66,10 @@
  */
 void
 mem_node_add_slice(pfn_t start, pfn_t end)
 {
         int mnode;
-        mnodeset_t newmask, oldmask;
 
         /*
          * DR will pass us the first pfn that is allocatable.
          * We need to round down to get the real start of
          * the slice.

@@ -93,15 +92,11 @@
                         mem_node_config[mnode].physmax = end;
         } else {
                 mem_node_config[mnode].physbase = start;
                 mem_node_config[mnode].physmax = end;
                 atomic_inc_16(&num_memnodes);
-                do {
-                        oldmask = memnodes_mask;
-                        newmask = memnodes_mask | (1ull << mnode);
-                } while (atomic_cas_64(&memnodes_mask, oldmask, newmask) !=
-                         oldmask);
+                atomic_or_64(&memnodes_mask, 1ull << mnode);
         }
         /*
          * Let the common lgrp framework know about the new memory
          */
         lgrp_config(LGRP_CONFIG_MEM_ADD, mnode, MEM_NODE_2_LGRPHAND(mnode));

@@ -117,11 +112,10 @@
 void
 mem_node_del_slice(pfn_t start, pfn_t end)
 {
         int mnode;
         pgcnt_t delta_pgcnt, node_size;
-        mnodeset_t omask, nmask;
 
         if (mem_node_physalign) {
                 start &= ~(btop(mem_node_physalign) - 1);
                 end = roundup(end, btop(mem_node_physalign)) - 1;
         }

@@ -154,14 +148,11 @@
 
                 /*
                  * Delete the whole node.
                  */
                 ASSERT(MNODE_PGCNT(mnode) == 0);
-                do {
-                        omask = memnodes_mask;
-                        nmask = omask & ~(1ull << mnode);
-                } while (atomic_cas_64(&memnodes_mask, omask, nmask) != omask);
+                atomic_and_64(&memnodes_mask, ~(1ull << mnode));
                 atomic_dec_16(&num_memnodes);
                 mem_node_config[mnode].exists = 0;
         }
 }
 

@@ -212,11 +203,10 @@
  */
 int
 mem_node_alloc()
 {
         int mnode;
-        mnodeset_t newmask, oldmask;
 
         /*
          * Find an unused memnode.  Update it atomically to prevent
          * a first time memnode creation race.
          */

@@ -229,14 +219,11 @@
                         panic("Out of free memnodes\n");
 
         mem_node_config[mnode].physbase = (uint64_t)-1;
         mem_node_config[mnode].physmax = 0;
         atomic_inc_16(&num_memnodes);
-        do {
-                oldmask = memnodes_mask;
-                newmask = memnodes_mask | (1ull << mnode);
-        } while (atomic_cas_64(&memnodes_mask, oldmask, newmask) != oldmask);
+        atomic_or_64(&memnodes_mask, 1ull << mnode);
 
         return (mnode);
 }
 
 /*