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Revert "Add limit and shrink policy for recycler (#15320)"

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This reverts commit c2e8814dce.
This commit is contained in:
behzad nouri
2021-04-07 11:15:38 -04:00
parent 6907a2366e
commit e405747409
24 changed files with 129 additions and 491 deletions
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414
perf/src/recycler.rs
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@@ -1,24 +1,7 @@
use rand::{thread_rng, Rng};
use solana_measure::measure::Measure;
use std::{
convert::TryFrom,
sync::{
atomic::{AtomicBool, AtomicUsize, Ordering},
Arc, Mutex, Weak,
},
time::Instant,
};
pub const DEFAULT_MINIMUM_OBJECT_COUNT: u32 = 1000;
pub const DEFAULT_SHRINK_PCT: u32 = 80;
pub const DEFAULT_MAX_ABOVE_SHRINK_PCT_COUNT: u32 = 10;
pub const DEFAULT_CHECK_SHRINK_INTERVAL_MS: u32 = 10000;
enum AllocationDecision<T> {
Reuse(T),
Allocate(u32, usize),
AllocationLimitReached,
}
use std::sync::atomic::AtomicBool;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::{Arc, Mutex, Weak};
#[derive(Debug, Default)]
struct RecyclerStats {
@@ -28,226 +11,36 @@ struct RecyclerStats {
max_gc: AtomicUsize,
}
#[derive(Debug, Default)]
struct RecyclerShrinkStats {
resulting_size: u32,
target_size: u32,
ideal_num_to_remove: u32,
shrink_elapsed: u64,
drop_elapsed: u64,
}
impl RecyclerShrinkStats {
fn report(&self, shrink_metric_name: &'static str) {
datapoint_info!(
shrink_metric_name,
("target_size", self.target_size as i64, i64),
("resulting_size", self.resulting_size as i64, i64),
("ideal_num_to_remove", self.ideal_num_to_remove as i64, i64),
("recycler_shrink_elapsed", self.shrink_elapsed as i64, i64),
("drop_elapsed", self.drop_elapsed as i64, i64)
);
}
}
#[derive(Clone)]
pub struct Recycler<T: Reset> {
#[derive(Clone, Default)]
pub struct Recycler<T> {
recycler: Arc<RecyclerX<T>>,
shrink_metric_name: &'static str,
}
impl<T: Default + Reset> Recycler<T> {
pub fn new_without_limit(shrink_metric_name: &'static str) -> Self {
Self {
recycler: Arc::new(RecyclerX::default()),
shrink_metric_name,
}
}
pub fn new_with_limit(shrink_metric_name: &'static str, limit: u32) -> Self {
Self {
recycler: Arc::new(RecyclerX::new(Some(limit))),
shrink_metric_name,
}
}
}
#[derive(Debug)]
pub struct ObjectPool<T: Reset> {
objects: Vec<T>,
shrink_pct: u32,
minimum_object_count: u32,
above_shrink_pct_count: u32,
max_above_shrink_pct_count: u32,
check_shrink_interval_ms: u32,
last_shrink_check_time: Instant,
pub total_allocated_count: u32,
limit: Option<u32>,
}
impl<T: Default + Reset> Default for ObjectPool<T> {
fn default() -> Self {
ObjectPool {
objects: vec![],
shrink_pct: DEFAULT_SHRINK_PCT,
minimum_object_count: DEFAULT_MINIMUM_OBJECT_COUNT,
above_shrink_pct_count: 0,
max_above_shrink_pct_count: DEFAULT_MAX_ABOVE_SHRINK_PCT_COUNT,
check_shrink_interval_ms: DEFAULT_CHECK_SHRINK_INTERVAL_MS,
last_shrink_check_time: Instant::now(),
total_allocated_count: 0,
limit: None,
}
}
}
impl<T: Default + Reset> ObjectPool<T> {
fn new(limit: Option<u32>) -> Self {
Self {
limit,
..Self::default()
}
}
fn len(&self) -> usize {
self.objects.len()
}
fn get_shrink_target(shrink_pct: u32, current_size: u32) -> u32 {
let shrink_pct = u64::from(shrink_pct);
let current_size = u64::from(current_size);
let shrink_target = shrink_pct
.saturating_mul(current_size)
.saturating_add(99)
.checked_div(100)
.unwrap_or(0);
u32::try_from(shrink_target).unwrap_or(u32::MAX)
}
fn shrink_if_necessary(
&mut self,
recycler_name: &'static str,
) -> Option<(RecyclerShrinkStats, Vec<T>)> {
let is_consistent = self.total_allocated_count as usize >= self.len();
assert!(
is_consistent,
"Object pool inconsistent: {} {} {}",
self.total_allocated_count,
self.len(),
recycler_name
);
if self.last_shrink_check_time.elapsed().as_millis() > self.check_shrink_interval_ms as u128
{
self.last_shrink_check_time = Instant::now();
let shrink_threshold_count =
Self::get_shrink_target(self.shrink_pct, self.total_allocated_count);
// If more than the shrink threshold of all allocated objects are sitting doing nothing,
// increment the `above_shrink_pct_count`.
if self.len() > self.minimum_object_count as usize
&& self.len() > shrink_threshold_count as usize
{
self.above_shrink_pct_count = self.above_shrink_pct_count.saturating_add(1);
} else {
self.above_shrink_pct_count = 0;
}
if self.above_shrink_pct_count as usize >= self.max_above_shrink_pct_count as usize {
let mut recycler_shrink_elapsed = Measure::start("recycler_shrink");
// Do the shrink
let target_size = std::cmp::max(self.minimum_object_count, shrink_threshold_count);
let ideal_num_to_remove = self.total_allocated_count.saturating_sub(target_size);
let mut shrink_removed_objects = Vec::with_capacity(ideal_num_to_remove as usize);
for _ in 0..ideal_num_to_remove {
if let Some(mut expired_object) = self.objects.pop() {
expired_object.unset_recycler();
// Drop these outside of the lock because the Drop() implmentation for
// certain objects like PinnedVec's can be expensive
shrink_removed_objects.push(expired_object);
// May not be able to shrink exactly `ideal_num_to_remove` objects since
// in the case of new allocations, `total_allocated_count` is incremented
// before the object is allocated (see `should_allocate_new` logic below).
// This race allows a difference of up to the number of threads allocating
// with this recycler.
self.total_allocated_count = self.total_allocated_count.saturating_sub(1);
} else {
break;
}
}
recycler_shrink_elapsed.stop();
self.above_shrink_pct_count = 0;
Some((
RecyclerShrinkStats {
resulting_size: self.total_allocated_count,
target_size,
ideal_num_to_remove,
shrink_elapsed: recycler_shrink_elapsed.as_us(),
// Filled in later
drop_elapsed: 0,
},
shrink_removed_objects,
))
} else {
None
}
} else {
None
}
}
fn make_allocation_decision(&mut self) -> AllocationDecision<T> {
if let Some(reused_object) = self.objects.pop() {
AllocationDecision::Reuse(reused_object)
} else if let Some(limit) = self.limit {
if self.total_allocated_count < limit {
self.total_allocated_count = self.total_allocated_count.saturating_add(1);
AllocationDecision::Allocate(self.total_allocated_count, self.len())
} else {
AllocationDecision::AllocationLimitReached
}
} else {
self.total_allocated_count = self.total_allocated_count.saturating_add(1);
AllocationDecision::Allocate(self.total_allocated_count, self.len())
}
}
}
#[derive(Debug)]
pub struct RecyclerX<T: Reset> {
gc: Mutex<ObjectPool<T>>,
pub struct RecyclerX<T> {
gc: Mutex<Vec<T>>,
stats: RecyclerStats,
id: usize,
}
impl<T: Default + Reset> Default for RecyclerX<T> {
impl<T: Default> Default for RecyclerX<T> {
fn default() -> RecyclerX<T> {
let id = thread_rng().gen_range(0, 1000);
trace!("new recycler..{}", id);
RecyclerX {
gc: Mutex::new(ObjectPool::default()),
gc: Mutex::new(vec![]),
stats: RecyclerStats::default(),
id,
}
}
}
impl<T: Default + Reset> RecyclerX<T> {
fn new(limit: Option<u32>) -> Self {
RecyclerX {
gc: Mutex::new(ObjectPool::new(limit)),
..Self::default()
}
}
}
pub trait Reset {
fn reset(&mut self);
fn warm(&mut self, size_hint: usize);
fn set_recycler(&mut self, recycler: Weak<RecyclerX<Self>>)
where
Self: std::marker::Sized;
fn unset_recycler(&mut self)
where
Self: std::marker::Sized;
}
lazy_static! {
@@ -263,21 +56,12 @@ fn warm_recyclers() -> bool {
}
impl<T: Default + Reset + Sized> Recycler<T> {
pub fn warmed(
num: u32,
size_hint: usize,
limit: Option<u32>,
shrink_metric_name: &'static str,
) -> Self {
assert!(num <= limit.unwrap_or(std::u32::MAX));
let new = Self {
recycler: Arc::new(RecyclerX::new(limit)),
shrink_metric_name,
};
pub fn warmed(num: usize, size_hint: usize) -> Self {
let new = Self::default();
if warm_recyclers() {
let warmed_items: Vec<_> = (0..num)
.map(|_| {
let mut item = new.allocate().unwrap();
let mut item = new.allocate("warming");
item.warm(size_hint);
item
})
@@ -289,55 +73,33 @@ impl<T: Default + Reset + Sized> Recycler<T> {
new
}
pub fn allocate(&self) -> Option<T> {
let (allocation_decision, shrink_output) = {
let mut object_pool = self
.recycler
.gc
.lock()
.expect("recycler lock in pb fn allocate");
pub fn allocate(&self, name: &'static str) -> T {
let new = self
.recycler
.gc
.lock()
.expect("recycler lock in pb fn allocate")
.pop();
let shrink_output = object_pool.shrink_if_necessary(self.shrink_metric_name);
// Grab the allocation decision and shrinking stats, do the expensive
// allocations/deallocations outside of the lock.
(object_pool.make_allocation_decision(), shrink_output)
};
if let Some((mut shrink_stats, shrink_removed_objects)) = shrink_output {
let mut shrink_removed_object_elapsed = Measure::start("shrink_removed_object_elapsed");
drop(shrink_removed_objects);
shrink_removed_object_elapsed.stop();
shrink_stats.drop_elapsed = shrink_removed_object_elapsed.as_us();
shrink_stats.report(self.shrink_metric_name);
if let Some(mut x) = new {
self.recycler.stats.reuse.fetch_add(1, Ordering::Relaxed);
x.reset();
return x;
}
match allocation_decision {
AllocationDecision::Reuse(mut reused_object) => {
self.recycler.stats.reuse.fetch_add(1, Ordering::Relaxed);
reused_object.reset();
Some(reused_object)
}
AllocationDecision::Allocate(total_allocated_count, recycled_len) => {
let mut t = T::default();
t.set_recycler(Arc::downgrade(&self.recycler));
if total_allocated_count % 1000 == 0 {
datapoint_info!(
"recycler_total_allocated_count",
("name", self.shrink_metric_name, String),
("count", total_allocated_count as i64, i64),
("recycled_len", recycled_len as i64, i64),
)
}
Some(t)
}
let total = self.recycler.stats.total.fetch_add(1, Ordering::Relaxed);
trace!(
"allocating new: total {} {:?} id: {} reuse: {} max_gc: {}",
total,
name,
self.recycler.id,
self.recycler.stats.reuse.load(Ordering::Relaxed),
self.recycler.stats.max_gc.load(Ordering::Relaxed),
);
AllocationDecision::AllocationLimitReached => None,
}
}
pub fn recycle_for_test(&self, x: T) {
self.recycler.recycle(x);
let mut t = T::default();
t.set_recycler(Arc::downgrade(&self.recycler));
t
}
}
@@ -345,7 +107,7 @@ impl<T: Default + Reset> RecyclerX<T> {
pub fn recycle(&self, x: T) {
let len = {
let mut gc = self.gc.lock().expect("recycler lock in pub fn recycle");
gc.objects.push(x);
gc.push(x);
gc.len()
};
@@ -375,8 +137,6 @@ impl<T: Default + Reset> RecyclerX<T> {
#[cfg(test)]
mod tests {
use super::*;
use crate::packet::PacketsRecycler;
use std::{thread::sleep, time::Duration};
impl Reset for u64 {
fn reset(&mut self) {
@@ -384,115 +144,19 @@ mod tests {
}
fn warm(&mut self, _size_hint: usize) {}
fn set_recycler(&mut self, _recycler: Weak<RecyclerX<Self>>) {}
fn unset_recycler(&mut self) {}
}
#[test]
fn test_recycler() {
let recycler = Recycler::new_without_limit("");
let mut y: u64 = recycler.allocate().unwrap();
let recycler = Recycler::default();
let mut y: u64 = recycler.allocate("test_recycler1");
assert_eq!(y, 0);
y = 20;
let recycler2 = recycler.clone();
recycler2.recycler.recycle(y);
assert_eq!(recycler.recycler.gc.lock().unwrap().len(), 1);
let z = recycler.allocate().unwrap();
let z = recycler.allocate("test_recycler2");
assert_eq!(z, 10);
assert_eq!(recycler.recycler.gc.lock().unwrap().len(), 0);
}
#[test]
fn test_recycler_limit() {
let limit = 10;
assert!(limit <= DEFAULT_MINIMUM_OBJECT_COUNT);
// Use PacketRecycler so that dropping the allocated object
// actually recycles
let recycler = PacketsRecycler::new_with_limit("", limit);
let mut allocated_items = vec![];
for i in 0..limit * 2 {
let x = recycler.allocate();
if i < limit {
allocated_items.push(x.unwrap());
} else {
assert!(x.is_none());
}
}
assert_eq!(
recycler.recycler.gc.lock().unwrap().total_allocated_count,
limit
);
assert_eq!(recycler.recycler.gc.lock().unwrap().len(), 0_usize);
drop(allocated_items);
assert_eq!(
recycler.recycler.gc.lock().unwrap().total_allocated_count,
limit
);
assert_eq!(recycler.recycler.gc.lock().unwrap().len(), limit as usize);
}
#[test]
fn test_recycler_shrink() {
let limit = DEFAULT_MINIMUM_OBJECT_COUNT * 2;
let max_above_shrink_pct_count = 2;
let shrink_pct = 80;
let recycler = PacketsRecycler::new_with_limit("", limit);
{
let mut locked_recycler = recycler.recycler.gc.lock().unwrap();
// Make the shrink interval a long time so shrinking doesn't happen yet
locked_recycler.check_shrink_interval_ms = std::u32::MAX;
// Set the count to one so that we shrink on every other allocation later.
locked_recycler.max_above_shrink_pct_count = max_above_shrink_pct_count;
locked_recycler.shrink_pct = shrink_pct;
}
let mut allocated_items = vec![];
for _ in 0..limit {
allocated_items.push(recycler.allocate().unwrap());
}
assert_eq!(
recycler.recycler.gc.lock().unwrap().total_allocated_count,
limit
);
assert_eq!(recycler.recycler.gc.lock().unwrap().len(), 0);
drop(allocated_items);
assert_eq!(recycler.recycler.gc.lock().unwrap().len(), limit as usize);
let shrink_interval = 10;
{
let mut locked_recycler = recycler.recycler.gc.lock().unwrap();
locked_recycler.check_shrink_interval_ms = shrink_interval;
}
let mut current_total_allocated_count =
recycler.recycler.gc.lock().unwrap().total_allocated_count;
// Shrink the recycler until it hits the minimum
let mut i = 0;
while current_total_allocated_count != DEFAULT_MINIMUM_OBJECT_COUNT {
sleep(Duration::from_millis(shrink_interval as u64 * 2));
recycler.allocate().unwrap();
let expected_above_shrink_pct_count = (i + 1) % max_above_shrink_pct_count;
assert_eq!(
recycler.recycler.gc.lock().unwrap().above_shrink_pct_count,
(i + 1) % max_above_shrink_pct_count
);
if expected_above_shrink_pct_count == 0 {
// Shrink happened, update the expected `current_total_allocated_count`;
current_total_allocated_count = std::cmp::max(
ObjectPool::<u64>::get_shrink_target(shrink_pct, current_total_allocated_count),
DEFAULT_MINIMUM_OBJECT_COUNT,
);
assert_eq!(
recycler.recycler.gc.lock().unwrap().total_allocated_count,
current_total_allocated_count
);
assert_eq!(
recycler.recycler.gc.lock().unwrap().len(),
current_total_allocated_count as usize
);
}
i += 1;
}
}
}