From 83b9ebf87d783abdde3ffbb73f12256d77906670 Mon Sep 17 00:00:00 2001
From: Zhang Junyang <junyang@stu.pku.edu.cn>
Date: Thu, 20 Mar 2025 20:22:48 +0800
Subject: [PATCH] Avoid repetitive locking for clearing cache

---
 osdk/deps/frame-allocator/src/cache.rs     | 20 +++++++++-------
 osdk/deps/frame-allocator/src/pools/mod.rs | 27 ++++++++++++----------
 2 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/osdk/deps/frame-allocator/src/cache.rs b/osdk/deps/frame-allocator/src/cache.rs
index 7a3957b0..6aa26bc8 100644
--- a/osdk/deps/frame-allocator/src/cache.rs
+++ b/osdk/deps/frame-allocator/src/cache.rs
@@ -71,13 +71,17 @@ impl<const NR_CONT_FRAMES: usize, const COUNT: usize> CacheArray<NR_CONT_FRAMES,
     /// deallocate to the global pool.
     fn dealloc(&mut self, guard: &DisabledLocalIrqGuard, addr: Paddr) {
         if self.push_front(addr).is_none() {
-            super::pools::dealloc(guard, addr, Self::segment_size());
-            let nr_to_dealloc = COUNT * 2 / 3;
+            let nr_to_dealloc = COUNT * 2 / 3 + 1;
 
-            for _ in 0..nr_to_dealloc {
-                let frame = self.pop_front().unwrap();
-                super::pools::dealloc(guard, frame, Self::segment_size());
-            }
+            let segments = (0..nr_to_dealloc).map(|i| {
+                if i == 0 {
+                    (addr, Self::segment_size())
+                } else {
+                    (self.pop_front().unwrap(), Self::segment_size())
+                }
+            });
+
+            super::pools::dealloc(guard, segments);
         };
     }
 
@@ -134,7 +138,7 @@ pub(super) fn alloc(guard: &DisabledLocalIrqGuard, layout: Layout) -> Option<Pad
 pub(super) fn dealloc(guard: &DisabledLocalIrqGuard, addr: Paddr, size: usize) {
     let nr_frames = size / PAGE_SIZE;
     if nr_frames > 4 {
-        super::pools::dealloc(guard, addr, size);
+        super::pools::dealloc(guard, [(addr, size)].into_iter());
         return;
     }
 
@@ -146,6 +150,6 @@ pub(super) fn dealloc(guard: &DisabledLocalIrqGuard, addr: Paddr, size: usize) {
         2 => cache.cache2.dealloc(guard, addr),
         3 => cache.cache3.dealloc(guard, addr),
         4 => cache.cache4.dealloc(guard, addr),
-        _ => super::pools::dealloc(guard, addr, size),
+        _ => super::pools::dealloc(guard, [(addr, size)].into_iter()),
     }
 }
diff --git a/osdk/deps/frame-allocator/src/pools/mod.rs b/osdk/deps/frame-allocator/src/pools/mod.rs
index 90d0b29e..e01561cd 100644
--- a/osdk/deps/frame-allocator/src/pools/mod.rs
+++ b/osdk/deps/frame-allocator/src/pools/mod.rs
@@ -82,8 +82,7 @@ pub(super) fn alloc(guard: &DisabledLocalIrqGuard, layout: Layout) -> Option<Pad
             do_dealloc(
                 &mut local_pool,
                 &mut global_pool,
-                chunk_addr + layout.size(),
-                allocated_size - layout.size(),
+                [(chunk_addr + layout.size(), allocated_size - layout.size())].into_iter(),
             );
         }
     }
@@ -95,12 +94,15 @@ pub(super) fn alloc(guard: &DisabledLocalIrqGuard, layout: Layout) -> Option<Pad
     chunk_addr
 }
 
-pub(super) fn dealloc(guard: &DisabledLocalIrqGuard, addr: Paddr, size: usize) {
+pub(super) fn dealloc(
+    guard: &DisabledLocalIrqGuard,
+    segments: impl Iterator<Item = (Paddr, usize)>,
+) {
     let local_pool_cell = LOCAL_POOL.get_with(guard);
     let mut local_pool = local_pool_cell.borrow_mut();
     let mut global_pool = OnDemandGlobalLock::new();
 
-    do_dealloc(&mut local_pool, &mut global_pool, addr, size);
+    do_dealloc(&mut local_pool, &mut global_pool, segments);
 
     balancing::balance(local_pool.deref_mut(), &mut global_pool);
 
@@ -120,15 +122,16 @@ pub(super) fn add_free_memory(_guard: &DisabledLocalIrqGuard, addr: Paddr, size:
 fn do_dealloc(
     local_pool: &mut BuddySet<MAX_LOCAL_BUDDY_ORDER>,
     global_pool: &mut OnDemandGlobalLock,
-    addr: Paddr,
-    size: usize,
+    segments: impl Iterator<Item = (Paddr, usize)>,
 ) {
-    split_to_chunks(addr, size).for_each(|(addr, order)| {
-        if order >= MAX_LOCAL_BUDDY_ORDER {
-            global_pool.get().insert_chunk(addr, order);
-        } else {
-            local_pool.insert_chunk(addr, order);
-        }
+    segments.for_each(|(addr, size)| {
+        split_to_chunks(addr, size).for_each(|(addr, order)| {
+            if order >= MAX_LOCAL_BUDDY_ORDER {
+                global_pool.get().insert_chunk(addr, order);
+            } else {
+                local_pool.insert_chunk(addr, order);
+            }
+        });
     });
 }