dsg/cloud-hypervisor
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

performance-metrics: Add warmup support for warm cache testing

Browse source 
Add warmup_iterations field to run iterations before measuring
performance. This complements existing cold start tests
by separating cache effects from steady state throughput.

New tests with 2 warmup iterations:
- block_qcow2_backing_qcow2_read_warm_MiBps
- block_qcow2_backing_raw_read_warm_MiBps

Results show warm cache is much faster and more consistent:
- QCOW2: 1766 MiB/s (4% variance) vs cold 960 MiB/s (73% variance)
- RAW: 1822 MiB/s (6% variance) vs cold 1300 MiB/s (55% variance)

RAW backing is 3% faster than QCOW2 in steady state.

Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
This commit is contained in:
Anatol Belski 2026-01-16 14:24:06 +01:00 • committed by Rob Bradford
parent dee7993538
commit cde7856d9e
1 changed files with 51 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

56
performance-metrics/src/main.rs
View file

@ -173,6 +173,7 @@ pub struct BlockControl {
pub struct PerformanceTestControl {
test_timeout: u32,
test_iterations: u32,
warmup_iterations: u32,
num_queues: Option<u32>,
queue_size: Option<u32>,
net_control: Option<(bool, bool)>, // First bool is for RX(true)/TX(false), second bool is for bandwidth or PPS
@ -183,8 +184,8 @@ pub struct PerformanceTestControl {
impl fmt::Display for PerformanceTestControl {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut output = format!(
"test_timeout = {}s, test_iterations = {}",
self.test_timeout, self.test_iterations
"test_timeout = {}s, test_iterations = {}, warmup_iterations = {}",
self.test_timeout, self.test_iterations, self.warmup_iterations
);
if let Some(o) = self.num_queues {
output = format!("{output}, num_queues = {o}");
@ -212,6 +213,7 @@ impl PerformanceTestControl {
Self {
test_timeout: 10,
test_iterations: 5,
warmup_iterations: 0,
num_queues: None,
queue_size: None,
net_control: None,
@ -233,6 +235,17 @@ struct PerformanceTest {
impl PerformanceTest {
pub fn run(&self, overrides: &PerformanceTestOverrides) -> PerformanceTestResult {
// Run warmup iterations if configured (results discarded)
for _ in 0..self.control.warmup_iterations {
if let Some(test_timeout) = overrides.test_timeout {
let mut control: PerformanceTestControl = self.control.clone();
control.test_timeout = test_timeout;
let _ = (self.func_ptr)(&control);
} else {
let _ = (self.func_ptr)(&self.control);
}
}
let mut metrics = Vec::new();
for _ in 0..overrides
.test_iterations
@ -265,8 +278,9 @@ impl PerformanceTest {
// Calculate the timeout for each test
// Note: To cover the setup/cleanup time, 20s is added for each iteration of the test
pub fn calc_timeout(&self, test_iterations: &Option<u32>, test_timeout: &Option<u32>) -> u64 {
((test_timeout.unwrap_or(self.control.test_timeout) + 20)
* test_iterations.unwrap_or(self.control.test_iterations)) as u64
let total_iterations = test_iterations.unwrap_or(self.control.test_iterations)
+ self.control.warmup_iterations;
((test_timeout.unwrap_or(self.control.test_timeout) + 20) * total_iterations) as u64
}
}
@ -319,7 +333,7 @@ mod adjuster {
}
}
const TEST_LIST: [PerformanceTest; 34] = [
const TEST_LIST: [PerformanceTest; 36] = [
PerformanceTest {
name: "boot_time_ms",
func_ptr: performance_boot_time,
@ -770,6 +784,38 @@ const TEST_LIST: [PerformanceTest; 34] = [
},
unit_adjuster: adjuster::Bps_to_MiBps,
},
PerformanceTest {
name: "block_qcow2_backing_qcow2_read_warm_MiBps",
func_ptr: performance_block_io,
control: PerformanceTestControl {
num_queues: Some(1),
queue_size: Some(128),
warmup_iterations: 2,
block_control: Some(BlockControl {
fio_ops: FioOps::Read,
bandwidth: true,
test_file: OVERLAY_WITH_QCOW2_BACKING,
}),
..PerformanceTestControl::default()
},
unit_adjuster: adjuster::Bps_to_MiBps,
},
PerformanceTest {
name: "block_qcow2_backing_raw_read_warm_MiBps",
func_ptr: performance_block_io,
control: PerformanceTestControl {
num_queues: Some(1),
queue_size: Some(128),
warmup_iterations: 2,
block_control: Some(BlockControl {
fio_ops: FioOps::Read,
bandwidth: true,
test_file: OVERLAY_WITH_RAW_BACKING,
}),
..PerformanceTestControl::default()
},
unit_adjuster: adjuster::Bps_to_MiBps,
},
];
fn run_test_with_timeout(