Remove USE_MEASURE

The initial performance monitoring for snmalloc used timing of small
operations to guide the design. This feature has not been maintained or
used for several years.

This commit removes the feature.

src/mem/alloc.h

@@ -7,7 +7,6 @@
 #endif
 
 #include "../pal/pal_consts.h"
-#include "../test/histogram.h"
 #include "allocstats.h"
 #include "chunkmap.h"
 #include "external_alloc.h"
@@ -1002,12 +1001,6 @@ namespace snmalloc
     template<ZeroMem zero_mem>
     SNMALLOC_FAST_PATH void* small_alloc(size_t size)
     {
-      MEASURE_TIME_MARKERS(
-        small_alloc,
-        4,
-        16,
-        MARKERS(zero_mem == YesZero ? "zeromem" : "nozeromem"));
-
       SNMALLOC_ASSUME(size <= SLAB_SIZE);
       sizeclass_t sizeclass = size_to_sizeclass(size);
       return small_alloc_inner<zero_mem>(sizeclass, size);
@@ -1212,7 +1205,6 @@ namespace snmalloc
     SNMALLOC_FAST_PATH void small_dealloc_offseted(
       Superslab* super, Slab* slab, void* p, sizeclass_t sizeclass)
     {
-      MEASURE_TIME(small_dealloc, 4, 16);
       stats().sizeclass_dealloc(sizeclass);
 
       small_dealloc_offseted_inner(super, slab, p, sizeclass);
@@ -1283,12 +1275,6 @@ namespace snmalloc
     template<ZeroMem zero_mem>
     void* medium_alloc(sizeclass_t sizeclass, size_t rsize, size_t size)
     {
-      MEASURE_TIME_MARKERS(
-        medium_alloc,
-        4,
-        16,
-        MARKERS(zero_mem == YesZero ? "zeromem" : "nozeromem"));
-
       sizeclass_t medium_class = sizeclass - NUM_SMALL_CLASSES;
 
       DLList<Mediumslab>* sc = &medium_classes[medium_class];
@@ -1382,7 +1368,6 @@ namespace snmalloc
     SNMALLOC_FAST_PATH
     void medium_dealloc_local(Mediumslab* slab, void* p, sizeclass_t sizeclass)
     {
-      MEASURE_TIME(medium_dealloc, 4, 16);
       stats().sizeclass_dealloc(sizeclass);
       bool was_full = Mediumslab::dealloc(slab, p);
 
@@ -1410,12 +1395,6 @@ namespace snmalloc
     template<ZeroMem zero_mem>
     void* large_alloc(size_t size)
     {
-      MEASURE_TIME_MARKERS(
-        large_alloc,
-        4,
-        16,
-        MARKERS(zero_mem == YesZero ? "zeromem" : "nozeromem"));
-
       if (NeedsInitialisation(this))
       {
         return InitThreadAllocator([size](void* alloc) {
@@ -1478,8 +1457,6 @@ namespace snmalloc
 
       size_t large_class = chunkmap_slab_kind - SUPERSLAB_BITS;
 
-      MEASURE_TIME(large_dealloc, 4, 16);
-
       chunkmap().clear_large_size(p, size);
 
       stats().large_dealloc(large_class);
@@ -1496,7 +1473,6 @@ namespace snmalloc
     SNMALLOC_FAST_PATH
     void remote_dealloc(RemoteAllocator* target, void* p, sizeclass_t sizeclass)
     {
-      MEASURE_TIME(remote_dealloc, 4, 16);
       SNMALLOC_ASSERT(target->trunc_id() != get_trunc_id());
 
       // Check whether this will overflow the cache first.  If we are a fake