diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index ff117ca8..9ab3fe6b 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -32,7 +32,7 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: --all-features -- -D warnings
+          args: --features=protobuf,flamegraph -- -D warnings
 
   test:
     name: Test
@@ -56,4 +56,4 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: test
-          args: --all-features
+          args: --features=protobuf,flamegraph
diff --git a/Cargo.toml b/Cargo.toml
index b583473d..d4c521d8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,7 @@ default = ["cpp"]
 flamegraph = ["inferno"]
 protobuf = ["prost", "prost-derive", "prost-build"]
 cpp = ["symbolic-demangle/cpp"]
+heap = []
 
 [dependencies]
 backtrace = "0.3"
@@ -21,9 +22,9 @@ lazy_static = "1.4"
 libc = "^0.2.66"
 log = "0.4"
 nix = "0.19"
-parking_lot = "0.11"
 tempfile = "3.1"
 thiserror = "1.0"
+spin = "0.7"
 
 inferno = { version = "0.10", default-features = false, features = ["nameattr"], optional = true }
 prost = { version = "0.6", optional = true }
@@ -53,6 +54,10 @@ required-features = ["protobuf"]
 name = "multithread_flamegraph"
 required-features = ["flamegraph"]
 
+[[example]]
+name = "heap_profiler"
+required-features = ["protobuf", "flamegraph", "heap"]
+
 [[bench]]
 name = "collector"
 path = "benches/collector.rs"
diff --git a/examples/heap_profiler.rs b/examples/heap_profiler.rs
new file mode 100644
index 00000000..35ae2cb1
--- /dev/null
+++ b/examples/heap_profiler.rs
@@ -0,0 +1,43 @@
+// Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
+
+use pprof::protos::Message;
+use pprof::AllocRecorder;
+use std::alloc::System;
+use std::fs::File;
+use std::io::Write;
+
+#[global_allocator]
+static ALLOC: AllocRecorder<System> = AllocRecorder::new(System);
+
+fn main() {
+    let guard = ALLOC.profile().unwrap();
+
+    memory_leak(65536);
+
+    match guard.report().build() {
+        Ok(report) => {
+            let mut file = File::create("profile.pb").unwrap();
+            let profile = report.pprof().unwrap();
+
+            let mut content = Vec::new();
+            profile.encode(&mut content).unwrap();
+            file.write_all(&content).unwrap();
+
+            let file = File::create("flamegraph.svg").unwrap();
+            report.flamegraph(file).unwrap();
+
+            println!("{:?}", report);
+        }
+        Err(_) => {}
+    };
+}
+
+fn memory_leak(size: usize) {
+    let b = Box::new(vec![0; size]);
+    Box::leak(b);
+
+    if size > 0 {
+        memory_leak(size / 2);
+        memory_leak(size / 2);
+    }
+}
diff --git a/src/collector.rs b/src/collector.rs
index c77a7eae..ee56477c 100644
--- a/src/collector.rs
+++ b/src/collector.rs
@@ -342,6 +342,40 @@ mod tests {
         }
     }
 
+    #[test]
+    fn collector_minus_test() {
+        let mut collector = Collector::new().unwrap();
+        let mut real_map = BTreeMap::new();
+
+        for item in 0..(1 << 12) * 4 {
+            for _ in 0..(item % 4) {
+                collector.add(item, 2).unwrap();
+            }
+        }
+
+        for item in 0..(1 << 12) * 4 {
+            for _ in 0..(item % 4) {
+                collector.add(item, -1).unwrap();
+            }
+        }
+
+        collector.try_iter().unwrap().for_each(|entry| {
+            add_map(&mut real_map, &entry);
+        });
+
+        for item in 0..(1 << 12) * 4 {
+            let count = (item % 4) as isize;
+            match real_map.get(&item) {
+                Some(value) => {
+                    assert_eq!(count, *value);
+                }
+                None => {
+                    assert_eq!(count, 0);
+                }
+            }
+        }
+    }
+
     extern "C" {
         static mut __malloc_hook: Option<extern "C" fn(size: usize) -> *mut c_void>;
 
diff --git a/src/heap_profiler.rs b/src/heap_profiler.rs
new file mode 100644
index 00000000..3d0ffcbb
--- /dev/null
+++ b/src/heap_profiler.rs
@@ -0,0 +1,162 @@
+// Copyright 2020 TiKV Project Authors. Licensed under Apache-2.0.
+
+use std::alloc::{GlobalAlloc, Layout};
+use std::ops::Deref;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use backtrace::Frame;
+use spin::RwLock;
+
+use crate::profiler::Profiler;
+use crate::Error;
+use crate::ReportBuilder;
+use crate::Result;
+use crate::MAX_DEPTH;
+
+lazy_static::lazy_static! {
+    pub(crate) static ref HEAP_PROFILER: RwLock<Result<Profiler>> = RwLock::new(Profiler::new());
+}
+
+pub struct AllocRecorder<T: GlobalAlloc> {
+    inner: T,
+    profiling: AtomicBool,
+}
+
+impl<T: GlobalAlloc> AllocRecorder<T> {
+    pub const fn new(inner: T) -> AllocRecorder<T> {
+        AllocRecorder {
+            inner,
+            profiling: AtomicBool::new(false),
+        }
+    }
+
+    pub fn profile(&self) -> Result<HeapProfilerGuard<'static, '_, T>> {
+        match HEAP_PROFILER.write().as_mut() {
+            Err(err) => {
+                log::error!("Error in creating profiler: {}", err);
+                Err(Error::CreatingError)
+            }
+            Ok(profiler) => match profiler.start() {
+                Ok(()) => {
+                    self.start();
+
+                    Ok(HeapProfilerGuard::<'static, '_, T> {
+                        profiler: &HEAP_PROFILER,
+                        alloc: self,
+                    })
+                }
+                Err(err) => Err(err),
+            },
+        }
+    }
+
+    pub(crate) fn start(&self) {
+        self.profiling.store(true, Ordering::SeqCst)
+    }
+
+    pub(crate) fn stop(&self) {
+        self.profiling.store(false, Ordering::SeqCst)
+    }
+}
+
+pub struct HeapReportBuilder<'a, 'b, 'c, T: GlobalAlloc> {
+    report_builder: ReportBuilder<'a>,
+    guard: &'a HeapProfilerGuard<'b, 'c, T>,
+}
+
+impl<T: GlobalAlloc> Drop for HeapReportBuilder<'_, '_, '_, T> {
+    fn drop(&mut self) {
+        self.guard.alloc.start()
+    }
+}
+
+impl<'a, T: GlobalAlloc> Deref for HeapReportBuilder<'a, '_, '_, T> {
+    type Target = ReportBuilder<'a>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.report_builder
+    }
+}
+
+pub struct HeapProfilerGuard<'a, 'b, T: GlobalAlloc> {
+    profiler: &'a RwLock<Result<Profiler>>,
+    alloc: &'b AllocRecorder<T>,
+}
+
+impl<T: GlobalAlloc> HeapProfilerGuard<'_, '_, T> {
+    /// Generate a report
+    pub fn report(&self) -> HeapReportBuilder<'_, '_, '_, T> {
+        self.alloc.stop();
+
+        HeapReportBuilder {
+            report_builder: ReportBuilder::new(&self.profiler),
+            guard: &self,
+        }
+    }
+}
+
+impl<T: GlobalAlloc> Drop for HeapProfilerGuard<'_, '_, T> {
+    fn drop(&mut self) {
+        self.alloc.stop();
+
+        match self.profiler.write().as_mut() {
+            Err(_) => {}
+            Ok(profiler) => match profiler.init() {
+                Ok(()) => {}
+                Err(err) => log::error!("error while reinitializing profiler {}", err),
+            },
+        }
+    }
+}
+
+unsafe impl<T: GlobalAlloc> GlobalAlloc for AllocRecorder<T> {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        if self.profiling.load(Ordering::SeqCst) {
+            let mut guard = HEAP_PROFILER.write();
+            if let Ok(profiler) = guard.as_mut() {
+                let mut bt: [Frame; MAX_DEPTH] = std::mem::MaybeUninit::uninit().assume_init();
+                let mut index = 0;
+
+                backtrace::trace_unsynchronized(|frame| {
+                    if index < MAX_DEPTH {
+                        bt[index] = frame.clone();
+                        index += 1;
+                        true
+                    } else {
+                        false
+                    }
+                });
+
+                let size = (layout.size() + layout.align()) as isize;
+                profiler.sample(&bt[0..index], &[], 0, size);
+            }
+        }
+
+        self.inner.alloc(layout)
+    }
+
+    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        if self.profiling.load(Ordering::SeqCst) {
+            let mut guard = HEAP_PROFILER.write();
+            if let Ok(profiler) = guard.as_mut() {
+                let mut bt: [Frame; MAX_DEPTH] = std::mem::MaybeUninit::uninit().assume_init();
+                let mut index = 0;
+
+                backtrace::trace_unsynchronized(|frame| {
+                    if index < MAX_DEPTH {
+                        bt[index] = frame.clone();
+                        index += 1;
+                        true
+                    } else {
+                        false
+                    }
+                });
+
+                let size = (layout.size() + layout.align()) as isize;
+                profiler.sample(&bt[0..index], &[], 0, -size);
+            }
+        }
+
+        self.inner.dealloc(ptr, layout);
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index c0b0f22b..115b0ffe 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -21,6 +21,8 @@
 //!};
 //! ```
 
+#![cfg_attr(feature = "heap", feature(const_fn))]
+
 /// Define the MAX supported stack depth. TODO: make this variable mutable.
 pub const MAX_DEPTH: usize = 32;
 
@@ -30,6 +32,9 @@ pub const MAX_THREAD_NAME: usize = 16;
 mod collector;
 mod error;
 mod frames;
+#[cfg(feature = "heap")]
+mod heap_profiler;
+
 mod profiler;
 mod report;
 mod timer;
@@ -37,6 +42,10 @@ mod timer;
 pub use self::collector::{Collector, StackHashCounter};
 pub use self::error::{Error, Result};
 pub use self::frames::{Frames, Symbol};
+
+#[cfg(feature = "heap")]
+pub use self::heap_profiler::{AllocRecorder, HeapProfilerGuard};
+
 pub use self::profiler::ProfilerGuard;
 pub use self::report::{Report, ReportBuilder};
 
diff --git a/src/profiler.rs b/src/profiler.rs
index 2a93d82b..da8c00e4 100644
--- a/src/profiler.rs
+++ b/src/profiler.rs
@@ -5,7 +5,7 @@ use std::os::raw::c_int;
 
 use backtrace::Frame;
 use nix::sys::signal;
-use parking_lot::RwLock;
+use spin::RwLock;
 
 use crate::collector::Collector;
 use crate::error::{Error, Result};
@@ -143,13 +143,13 @@ extern "C" fn perf_signal_handler(_signal: c_int) {
             write_thread_name(current_thread, &mut name);
 
             let name = unsafe { std::ffi::CStr::from_ptr(name_ptr) };
-            profiler.sample(&bt[0..index], name.to_bytes(), current_thread as u64);
+            profiler.sample(&bt[0..index], name.to_bytes(), current_thread as u64, 1);
         }
     }
 }
 
 impl Profiler {
-    fn new() -> Result<Self> {
+    pub fn new() -> Result<Self> {
         Ok(Profiler {
             data: Collector::new()?,
             sample_counter: 0,
@@ -171,7 +171,7 @@ impl Profiler {
         }
     }
 
-    fn init(&mut self) -> Result<()> {
+    pub(crate) fn init(&mut self) -> Result<()> {
         self.sample_counter = 0;
         self.data = Collector::new()?;
         self.running = false;
@@ -206,11 +206,17 @@ impl Profiler {
     }
 
     // This function has to be AS-safe
-    pub fn sample(&mut self, backtrace: &[Frame], thread_name: &[u8], thread_id: u64) {
+    pub fn sample(
+        &mut self,
+        backtrace: &[Frame],
+        thread_name: &[u8],
+        thread_id: u64,
+        count: isize,
+    ) {
         let frames = UnresolvedFrames::new(backtrace, thread_name, thread_id);
         self.sample_counter += 1;
 
-        if let Ok(()) = self.data.add(frames, 1) {}
+        if let Ok(()) = self.data.add(frames, count) {}
     }
 }
 
diff --git a/src/report.rs b/src/report.rs
index 91082f4f..430a94ed 100644
--- a/src/report.rs
+++ b/src/report.rs
@@ -3,11 +3,10 @@
 use std::collections::HashMap;
 use std::fmt::{Debug, Formatter};
 
-use parking_lot::RwLock;
+use spin::RwLock;
 
 use crate::frames::{Frames, UnresolvedFrames};
 use crate::profiler::Profiler;
-
 use crate::{Error, Result};
 
 /// The final presentation of a report which is actually an `HashMap` from `Frames` to isize (count).