SC: Remove global data.

The global data is mostly only used at initialization, or for easy access to
values we could compute statically.  Instead of consuming that space (and
risking TLB misses), we can just pass around a pointer to stack data during
bootstrapping.

include/jemalloc/internal/sc.h

@@ -182,6 +182,7 @@
 #define SC_NGROUP (1ULL << SC_LG_NGROUP)
 #define SC_PTR_BITS ((1ULL << LG_SIZEOF_PTR) * 8)
 #define SC_NTINY (LG_QUANTUM - SC_LG_TINY_MIN)
+#define SC_LG_TINY_MAXCLASS (LG_QUANTUM > SC_LG_TINY_MIN ? LG_QUANTUM - 1 : -1)
 #define SC_NPSEUDO SC_NGROUP
 #define SC_LG_FIRST_REGULAR_BASE (LG_QUANTUM + SC_LG_NGROUP)
 /*
@@ -200,7 +201,7 @@
  * because delta may be smaller than a page, this is not the same as the number
  * of size classes that are *multiples* of the page size.
  */
-#define SC_NPSIZES_MAX (						\
+#define SC_NPSIZES (							\
     /* Start with all the size classes. */				\
     SC_NSIZES								\
     /* Subtract out those groups with too small a base. */		\
@@ -209,11 +210,8 @@
     - SC_NPSEUDO							\
     /* And the tiny group. */						\
     - SC_NTINY								\
-    /*									\
-     * In the lg_base == lg_page - 1 group, only the last sc is big	\
-     * enough to make it to lg_page.					\
-     */									\
-    - (SC_NGROUP - 1))
+    /* Groups where ndelta*delta is not a multiple of the page size. */	\
+    - (2 * (SC_NGROUP)))
 
 /*
  * We declare a size class is binnable if size < page size * group. Or, in other
@@ -314,7 +312,6 @@ struct sc_data_s {
 	sc_t sc[SC_NSIZES];
 };
 
-extern sc_data_t sc_data_global;
 void sc_data_init(sc_data_t *data);
 /*
  * Updates slab sizes in [begin, end] to be pgs pages in length, if possible.
@@ -322,6 +319,6 @@ void sc_data_init(sc_data_t *data);
  */
 void sc_data_update_slab_size(sc_data_t *data, size_t begin, size_t end,
     int pgs);
-void sc_boot();
+void sc_boot(sc_data_t *data);
 
 #endif /* JEMALLOC_INTERNAL_SC_H */