Remove dead field in VMMap (#1320)

Author: k-sareen

src/util/heap/layout/map.rs

@@ -84,6 +84,4 @@ pub trait VMMap: Sync {
     /// Get the space descriptor for the given address. Return SpaceDescriptor::UNINITIALIZED if the
     /// address is not within the MMTk heap range, or not within MMTk spaces.
     fn get_descriptor_for_address(&self, address: Address) -> SpaceDescriptor;
-
-    fn add_to_cumulative_committed_pages(&self, pages: usize);
 }

src/util/heap/layout/map32.rs

@@ -9,7 +9,6 @@ use crate::util::heap::space_descriptor::SpaceDescriptor;
 use crate::util::int_array_freelist::IntArrayFreeList;
 use crate::util::Address;
 use std::cell::UnsafeCell;
-use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::{Mutex, MutexGuard};
 
 pub struct Map32 {
@@ -27,12 +26,6 @@ pub struct Map32Inner {
     total_available_discontiguous_chunks: usize,
     finalized: bool,
     descriptor_map: Vec<SpaceDescriptor>,
-
-    // TODO: Is this the right place for this field?
-    // This used to be a global variable. When we remove global states, this needs to be put somewhere.
-    // Currently I am putting it here, as for where this variable is used, we already have
-    // references to vm_map - so it is convenient to put it here.
-    cumulative_committed_pages: AtomicUsize,
 }
 
 unsafe impl Send for Map32 {}
@@ -51,7 +44,6 @@ impl Map32 {
                 total_available_discontiguous_chunks: 0,
                 finalized: false,
                 descriptor_map: vec![SpaceDescriptor::UNINITIALIZED; max_chunks],
-                cumulative_committed_pages: AtomicUsize::new(0),
             }),
             sync: Mutex::new(()),
         }
@@ -260,11 +252,6 @@ impl VMMap for Map32 {
             .copied()
             .unwrap_or(SpaceDescriptor::UNINITIALIZED)
     }
-
-    fn add_to_cumulative_committed_pages(&self, pages: usize) {
-        self.cumulative_committed_pages
-            .fetch_add(pages, Ordering::Relaxed);
-    }
 }
 
 impl Map32 {

src/util/heap/layout/map64.rs

@@ -10,7 +10,6 @@ use crate::util::memory::MmapStrategy;
 use crate::util::raw_memory_freelist::RawMemoryFreeList;
 use crate::util::Address;
 use std::cell::UnsafeCell;
-use std::sync::atomic::{AtomicUsize, Ordering};
 
 const NON_MAP_FRACTION: f64 = 1.0 - 8.0 / 4096.0;
 
@@ -23,12 +22,6 @@ struct Map64Inner {
     descriptor_map: Vec<SpaceDescriptor>,
     base_address: Vec<Address>,
     high_water: Vec<Address>,
-
-    // TODO: Is this the right place for this field?
-    // This used to be a global variable. When we remove global states, this needs to be put somewhere.
-    // Currently I am putting it here, as for where this variable is used, we already have
-    // references to vm_map - so it is convenient to put it here.
-    cumulative_committed_pages: AtomicUsize,
 }
 
 unsafe impl Send for Map64 {}
@@ -53,7 +46,6 @@ impl Map64 {
                 high_water,
                 base_address,
                 finalized: false,
-                cumulative_committed_pages: AtomicUsize::new(0),
             }),
         }
     }
@@ -212,12 +204,6 @@ impl VMMap for Map64 {
             SpaceDescriptor::UNINITIALIZED
         }
     }
-
-    fn add_to_cumulative_committed_pages(&self, pages: usize) {
-        self.inner()
-            .cumulative_committed_pages
-            .fetch_add(pages, Ordering::Relaxed);
-    }
 }
 
 impl Map64 {

src/util/heap/pageresource.rs

@@ -2,7 +2,6 @@ use crate::util::address::Address;
 use crate::util::conversions;
 use crate::util::freelist::FreeList;
 use crate::util::opaque_pointer::*;
-use crate::vm::ActivePlan;
 use std::sync::Mutex;
 
 use super::layout::VMMap;
@@ -70,14 +69,10 @@ pub trait PageResource<VM: VMBinding>: 'static {
      * This *MUST* be called by each PageResource during the
      * allocPages, and the caller must hold the lock.
      */
-    fn commit_pages(&self, reserved_pages: usize, actual_pages: usize, tls: VMThread) {
+    fn commit_pages(&self, reserved_pages: usize, actual_pages: usize, _tls: VMThread) {
         let delta = actual_pages - reserved_pages;
         self.common().accounting.reserve(delta);
         self.common().accounting.commit(actual_pages);
-        if VM::VMActivePlan::is_mutator(tls) {
-            self.vm_map()
-                .add_to_cumulative_committed_pages(actual_pages);
-        }
     }
 
     fn reserved_pages(&self) -> usize {