This commit introduces memory tracker with jemalloc extent hooks which fully works in case when jemalloc config is following:
MALLOC_CONF="retain:false,percpu_arena:percpu,oversize_threshold:1000000000000,muzzy_decay_ms:0,dirty_decay_ms:0" \
./configure \
--disable-cxx \
$COMMON_CONFIGURE_FLAGS \
--with-malloc-conf="retain:false,percpu_arena:percpu,oversize_threshold:1000000000000,muzzy_decay_ms:0,dirty_decay_ms:0"
This config will for jemalloc not to use lazy purge or MADV_FREE(muzzy_decay_ms=0 and dirty_decay_ms=0), it will force jemalloc not to use
custom arena for huge allocations (oversize_threshold) and it will force jemalloc not extend virtual memory indefinitely (retain=false)
and therefore call alloc hook when allocation actually takes place.
Only problem is if we do huge allocations which are not mapped on alloc directly, in that case jemalloc uses cache and we can overcounter
allocation size.
