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Make the memory reporting multi-process aware (#35863)

Browse source 
So far the memory reporter aggregates reports from all processes, and
runs the system reporter only in the main process. Instead it is
desirable to have per-process reports. We do so by:
- creating a ProcessReports struct that holds includes the pid in
addition to the reports themselves.
- running the system memory reporter also in content processes.
- updating the about:memory page to create one report per process, and
add useful information like the pid and the urls loaded in a given
process.

<!-- Please describe your changes on the following line: -->


---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by
`[X]` when the step is complete, and replace `___` with appropriate
data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors


![image](https://github.com/user-attachments/assets/0bafe140-539d-4d6a-8316-639309a22d4a)

Signed-off-by: webbeef <me@webbeef.org>
This commit is contained in:
webbeef 2025-04-04 22:42:12 -07:00 • committed by GitHub
parent 76edcff202
commit aef8537d75
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
15 changed files with 551 additions and 424 deletions
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1
components/profile/Cargo.toml
View file

@ -14,6 +14,7 @@ path = "lib.rs"
[dependencies]
base = { workspace = true }
ipc-channel = { workspace = true }
log = { workspace = true }
parking_lot = { workspace = true }
profile_traits = { workspace = true }
serde = { workspace = true }

3
components/profile/lib.rs
View file

@ -4,7 +4,8 @@
#![deny(unsafe_code)]
#[allow(unsafe_code)]
pub mod mem;
#[allow(unsafe_code)]
pub mod system_reporter;
pub mod time;
pub mod trace_dump;

376
components/profile/mem.rs
View file

@ -10,9 +10,13 @@ use std::thread;
use ipc_channel::ipc::{self, IpcReceiver};
use ipc_channel::router::ROUTER;
use log::debug;
use profile_traits::mem::{
MemoryReportResult, ProfilerChan, ProfilerMsg, Report, Reporter, ReporterRequest, ReportsChan,
};
use serde::Serialize;
use crate::system_reporter;
pub struct Profiler {
/// The port through which messages are received.
@ -22,9 +26,6 @@ pub struct Profiler {
reporters: HashMap<String, Reporter>,
}
const JEMALLOC_HEAP_ALLOCATED_STR: &str = "jemalloc-heap-allocated";
const SYSTEM_HEAP_ALLOCATED_STR: &str = "system-heap-allocated";
impl Profiler {
pub fn create() -> ProfilerChan {
let (chan, port) = ipc::channel().unwrap();
@ -53,7 +54,7 @@ impl Profiler {
}),
);
mem_profiler_chan.send(ProfilerMsg::RegisterReporter(
"system".to_owned(),
"system-main".to_owned(),
Reporter(system_reporter_sender),
));
@ -78,6 +79,7 @@ impl Profiler {
fn handle_msg(&mut self, msg: ProfilerMsg) -> bool {
match msg {
ProfilerMsg::RegisterReporter(name, reporter) => {
debug!("Registering memory reporter: {}", name);
// Panic if it has already been registered.
let name_clone = name.clone();
match self.reporters.insert(name, reporter) {
@ -87,6 +89,7 @@ impl Profiler {
},
ProfilerMsg::UnregisterReporter(name) => {
debug!("Unregistering memory reporter: {}", name);
// Panic if it hasn't previously been registered.
match self.reporters.remove(&name) {
Some(_) => true,
@ -95,8 +98,28 @@ impl Profiler {
},
ProfilerMsg::Report(sender) => {
let main_pid = std::process::id();
#[derive(Serialize)]
struct JsonReport {
pid: u32,
#[serde(rename = "isMainProcess")]
is_main_process: bool,
reports: Vec<Report>,
}
let reports = self.collect_reports();
let content = serde_json::to_string(&reports)
// Turn the pid -> reports map into a vector and add the
// hint to find the main process.
let json_reports: Vec<JsonReport> = reports
.into_iter()
.map(|(pid, reports)| JsonReport {
pid,
reports,
is_main_process: pid == main_pid,
})
.collect();
let content = serde_json::to_string(&json_reports)
.unwrap_or_else(|_| "{ error: \"failed to create memory report\"}".to_owned());
let _ = sender.send(MemoryReportResult { content });
true
@ -106,347 +129,20 @@ impl Profiler {
}
}
fn collect_reports(&self) -> Vec<Report> {
let mut result = vec![];
/// Returns a map of pid -> reports
fn collect_reports(&self) -> HashMap<u32, Vec<Report>> {
let mut result = HashMap::new();
for reporter in self.reporters.values() {
let (chan, port) = ipc::channel().unwrap();
reporter.collect_reports(ReportsChan(chan));
if let Ok(mut reports) = port.recv() {
result.append(&mut reports);
result
.entry(reports.pid)
.or_insert(vec![])
.append(&mut reports.reports);
}
}
result
}
}
//---------------------------------------------------------------------------
mod system_reporter {
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use std::ffi::CString;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use std::mem::size_of;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use std::ptr::null_mut;
#[cfg(all(target_os = "linux", target_env = "gnu"))]
use libc::c_int;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use libc::{c_void, size_t};
use profile_traits::mem::{Report, ReportKind, ReporterRequest};
use profile_traits::path;
#[cfg(target_os = "macos")]
use task_info::task_basic_info::{resident_size, virtual_size};
use super::{JEMALLOC_HEAP_ALLOCATED_STR, SYSTEM_HEAP_ALLOCATED_STR};
/// Collects global measurements from the OS and heap allocators.
pub fn collect_reports(request: ReporterRequest) {
let mut reports = vec![];
{
let mut report = |path, size| {
if let Some(size) = size {
reports.push(Report {
path,
kind: ReportKind::NonExplicitSize,
size,
});
}
};
// Virtual and physical memory usage, as reported by the OS.
report(path!["vsize"], vsize());
report(path!["resident"], resident());
// Memory segments, as reported by the OS.
for seg in resident_segments() {
report(path!["resident-according-to-smaps", seg.0], Some(seg.1));
}
// Total number of bytes allocated by the application on the system
// heap.
report(path![SYSTEM_HEAP_ALLOCATED_STR], system_heap_allocated());
// The descriptions of the following jemalloc measurements are taken
// directly from the jemalloc documentation.
// "Total number of bytes allocated by the application."
report(
path![JEMALLOC_HEAP_ALLOCATED_STR],
jemalloc_stat("stats.allocated"),
);
// "Total number of bytes in active pages allocated by the application.
// This is a multiple of the page size, and greater than or equal to
// |stats.allocated|."
report(path!["jemalloc-heap-active"], jemalloc_stat("stats.active"));
// "Total number of bytes in chunks mapped on behalf of the application.
// This is a multiple of the chunk size, and is at least as large as
// |stats.active|. This does not include inactive chunks."
report(path!["jemalloc-heap-mapped"], jemalloc_stat("stats.mapped"));
}
request.reports_channel.send(reports);
}
#[cfg(all(target_os = "linux", target_env = "gnu"))]
unsafe extern "C" {
fn mallinfo() -> struct_mallinfo;
}
#[cfg(all(target_os = "linux", target_env = "gnu"))]
#[repr(C)]
pub struct struct_mallinfo {
arena: c_int,
ordblks: c_int,
smblks: c_int,
hblks: c_int,
hblkhd: c_int,
usmblks: c_int,
fsmblks: c_int,
uordblks: c_int,
fordblks: c_int,
keepcost: c_int,
}
#[cfg(all(target_os = "linux", target_env = "gnu"))]
fn system_heap_allocated() -> Option<usize> {
let info: struct_mallinfo = unsafe { mallinfo() };
// The documentation in the glibc man page makes it sound like |uordblks| would suffice,
// but that only gets the small allocations that are put in the brk heap. We need |hblkhd|
// as well to get the larger allocations that are mmapped.
//
// These fields are unfortunately |int| and so can overflow (becoming negative) if memory
// usage gets high enough. So don't report anything in that case. In the non-overflow case
// we cast the two values to usize before adding them to make sure the sum also doesn't
// overflow.
if info.hblkhd < 0 || info.uordblks < 0 {
None
} else {
Some(info.hblkhd as usize + info.uordblks as usize)
}
}
#[cfg(not(all(target_os = "linux", target_env = "gnu")))]
fn system_heap_allocated() -> Option<usize> {
None
}
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use tikv_jemalloc_sys::mallctl;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
fn jemalloc_stat(value_name: &str) -> Option<usize> {
// Before we request the measurement of interest, we first send an "epoch"
// request. Without that jemalloc gives cached statistics(!) which can be
// highly inaccurate.
let epoch_name = "epoch";
let epoch_c_name = CString::new(epoch_name).unwrap();
let mut epoch: u64 = 0;
let epoch_ptr = &mut epoch as *mut _ as *mut c_void;
let mut epoch_len = size_of::<u64>() as size_t;
let value_c_name = CString::new(value_name).unwrap();
let mut value: size_t = 0;
let value_ptr = &mut value as *mut _ as *mut c_void;
let mut value_len = size_of::<size_t>() as size_t;
// Using the same values for the `old` and `new` parameters is enough
// to get the statistics updated.
let rv = unsafe {
mallctl(
epoch_c_name.as_ptr(),
epoch_ptr,
&mut epoch_len,
epoch_ptr,
epoch_len,
)
};
if rv != 0 {
return None;
}
let rv = unsafe {
mallctl(
value_c_name.as_ptr(),
value_ptr,
&mut value_len,
null_mut(),
0,
)
};
if rv != 0 {
return None;
}
Some(value as usize)
}
#[cfg(any(target_os = "windows", target_env = "ohos"))]
fn jemalloc_stat(_value_name: &str) -> Option<usize> {
None
}
#[cfg(target_os = "linux")]
fn page_size() -> usize {
unsafe { ::libc::sysconf(::libc::_SC_PAGESIZE) as usize }
}
#[cfg(target_os = "linux")]
fn proc_self_statm_field(field: usize) -> Option<usize> {
use std::fs::File;
use std::io::Read;
let mut f = File::open("/proc/self/statm").ok()?;
let mut contents = String::new();
f.read_to_string(&mut contents).ok()?;
let s = contents.split_whitespace().nth(field)?;
let npages = s.parse::<usize>().ok()?;
Some(npages * page_size())
}
#[cfg(target_os = "linux")]
fn vsize() -> Option<usize> {
proc_self_statm_field(0)
}
#[cfg(target_os = "linux")]
fn resident() -> Option<usize> {
proc_self_statm_field(1)
}
#[cfg(target_os = "macos")]
fn vsize() -> Option<usize> {
virtual_size()
}
#[cfg(target_os = "macos")]
fn resident() -> Option<usize> {
resident_size()
}
#[cfg(not(any(target_os = "linux", target_os = "macos")))]
fn vsize() -> Option<usize> {
None
}
#[cfg(not(any(target_os = "linux", target_os = "macos")))]
fn resident() -> Option<usize> {
None
}
#[cfg(target_os = "linux")]
fn resident_segments() -> Vec<(String, usize)> {
use std::collections::HashMap;
use std::collections::hash_map::Entry;
use std::fs::File;
use std::io::{BufRead, BufReader};
use regex::Regex;
// The first line of an entry in /proc/<pid>/smaps looks just like an entry
// in /proc/<pid>/maps:
//
// address perms offset dev inode pathname
// 02366000-025d8000 rw-p 00000000 00:00 0 [heap]
//
// Each of the following lines contains a key and a value, separated
// by ": ", where the key does not contain either of those characters.
// For example:
//
// Rss: 132 kB
let f = match File::open("/proc/self/smaps") {
Ok(f) => BufReader::new(f),
Err(_) => return vec![],
};
let seg_re = Regex::new(
r"^[:xdigit:]+-[:xdigit:]+ (....) [:xdigit:]+ [:xdigit:]+:[:xdigit:]+ \d+ +(.*)",
)
.unwrap();
let rss_re = Regex::new(r"^Rss: +(\d+) kB").unwrap();
// We record each segment's resident size.
let mut seg_map: HashMap<String, usize> = HashMap::new();
#[derive(PartialEq)]
enum LookingFor {
Segment,
Rss,
}
let mut looking_for = LookingFor::Segment;
let mut curr_seg_name = String::new();
// Parse the file.
for line in f.lines() {
let line = match line {
Ok(line) => line,
Err(_) => continue,
};
if looking_for == LookingFor::Segment {
// Look for a segment info line.
let cap = match seg_re.captures(&line) {
Some(cap) => cap,
None => continue,
};
let perms = cap.get(1).unwrap().as_str();
let pathname = cap.get(2).unwrap().as_str();
// Construct the segment name from its pathname and permissions.
curr_seg_name.clear();
if pathname.is_empty() || pathname.starts_with("[stack:") {
// Anonymous memory. Entries marked with "[stack:nnn]"
// look like thread stacks but they may include other
// anonymous mappings, so we can't trust them and just
// treat them as entirely anonymous.
curr_seg_name.push_str("anonymous");
} else {
curr_seg_name.push_str(pathname);
}
curr_seg_name.push_str(" (");
curr_seg_name.push_str(perms);
curr_seg_name.push(')');
looking_for = LookingFor::Rss;
} else {
// Look for an "Rss:" line.
let cap = match rss_re.captures(&line) {
Some(cap) => cap,
None => continue,
};
let rss = cap.get(1).unwrap().as_str().parse::<usize>().unwrap() * 1024;
if rss > 0 {
// Aggregate small segments into "other".
let seg_name = if rss < 512 * 1024 {
"other".to_owned()
} else {
curr_seg_name.clone()
};
match seg_map.entry(seg_name) {
Entry::Vacant(entry) => {
entry.insert(rss);
},
Entry::Occupied(mut entry) => *entry.get_mut() += rss,
}
}
looking_for = LookingFor::Segment;
}
}
// Note that the sum of all these segments' RSS values differs from the "resident"
// measurement obtained via /proc/<pid>/statm in resident(). It's unclear why this
// difference occurs; for some processes the measurements match, but for Servo they do not.
seg_map.into_iter().collect()
}
#[cfg(not(target_os = "linux"))]
fn resident_segments() -> Vec<(String, usize)> {
vec![]
}
}

332
components/profile/system_reporter.rs Normal file
View file

@ -0,0 +1,332 @@
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use std::ffi::CString;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use std::mem::size_of;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use std::ptr::null_mut;
#[cfg(all(target_os = "linux", target_env = "gnu"))]
use libc::c_int;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use libc::{c_void, size_t};
use profile_traits::mem::{ProcessReports, Report, ReportKind, ReporterRequest};
use profile_traits::path;
#[cfg(target_os = "macos")]
use task_info::task_basic_info::{resident_size, virtual_size};
const JEMALLOC_HEAP_ALLOCATED_STR: &str = "jemalloc-heap-allocated";
const SYSTEM_HEAP_ALLOCATED_STR: &str = "system-heap-allocated";
/// Collects global measurements from the OS and heap allocators.
pub fn collect_reports(request: ReporterRequest) {
let mut reports = vec![];
{
let mut report = |path, size| {
if let Some(size) = size {
reports.push(Report {
path,
kind: ReportKind::NonExplicitSize,
size,
});
}
};
// Virtual and physical memory usage, as reported by the OS.
report(path!["vsize"], vsize());
report(path!["resident"], resident());
// Memory segments, as reported by the OS.
for seg in resident_segments() {
report(path!["resident-according-to-smaps", seg.0], Some(seg.1));
}
// Total number of bytes allocated by the application on the system
// heap.
report(path![SYSTEM_HEAP_ALLOCATED_STR], system_heap_allocated());
// The descriptions of the following jemalloc measurements are taken
// directly from the jemalloc documentation.
// "Total number of bytes allocated by the application."
report(
path![JEMALLOC_HEAP_ALLOCATED_STR],
jemalloc_stat("stats.allocated"),
);
// "Total number of bytes in active pages allocated by the application.
// This is a multiple of the page size, and greater than or equal to
// |stats.allocated|."
report(path!["jemalloc-heap-active"], jemalloc_stat("stats.active"));
// "Total number of bytes in chunks mapped on behalf of the application.
// This is a multiple of the chunk size, and is at least as large as
// |stats.active|. This does not include inactive chunks."
report(path!["jemalloc-heap-mapped"], jemalloc_stat("stats.mapped"));
}
request.reports_channel.send(ProcessReports::new(reports));
}
#[cfg(all(target_os = "linux", target_env = "gnu"))]
unsafe extern "C" {
fn mallinfo() -> struct_mallinfo;
}
#[cfg(all(target_os = "linux", target_env = "gnu"))]
#[repr(C)]
pub struct struct_mallinfo {
arena: c_int,
ordblks: c_int,
smblks: c_int,
hblks: c_int,
hblkhd: c_int,
usmblks: c_int,
fsmblks: c_int,
uordblks: c_int,
fordblks: c_int,
keepcost: c_int,
}
#[cfg(all(target_os = "linux", target_env = "gnu"))]
fn system_heap_allocated() -> Option<usize> {
let info: struct_mallinfo = unsafe { mallinfo() };
// The documentation in the glibc man page makes it sound like |uordblks| would suffice,
// but that only gets the small allocations that are put in the brk heap. We need |hblkhd|
// as well to get the larger allocations that are mmapped.
//
// These fields are unfortunately |int| and so can overflow (becoming negative) if memory
// usage gets high enough. So don't report anything in that case. In the non-overflow case
// we cast the two values to usize before adding them to make sure the sum also doesn't
// overflow.
if info.hblkhd < 0 || info.uordblks < 0 {
None
} else {
Some(info.hblkhd as usize + info.uordblks as usize)
}
}
#[cfg(not(all(target_os = "linux", target_env = "gnu")))]
fn system_heap_allocated() -> Option<usize> {
None
}
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
use tikv_jemalloc_sys::mallctl;
#[cfg(not(any(target_os = "windows", target_env = "ohos")))]
fn jemalloc_stat(value_name: &str) -> Option<usize> {
// Before we request the measurement of interest, we first send an "epoch"
// request. Without that jemalloc gives cached statistics(!) which can be
// highly inaccurate.
let epoch_name = "epoch";
let epoch_c_name = CString::new(epoch_name).unwrap();
let mut epoch: u64 = 0;
let epoch_ptr = &mut epoch as *mut _ as *mut c_void;
let mut epoch_len = size_of::<u64>() as size_t;
let value_c_name = CString::new(value_name).unwrap();
let mut value: size_t = 0;
let value_ptr = &mut value as *mut _ as *mut c_void;
let mut value_len = size_of::<size_t>() as size_t;
// Using the same values for the `old` and `new` parameters is enough
// to get the statistics updated.
let rv = unsafe {
mallctl(
epoch_c_name.as_ptr(),
epoch_ptr,
&mut epoch_len,
epoch_ptr,
epoch_len,
)
};
if rv != 0 {
return None;
}
let rv = unsafe {
mallctl(
value_c_name.as_ptr(),
value_ptr,
&mut value_len,
null_mut(),
0,
)
};
if rv != 0 {
return None;
}
Some(value as usize)
}
#[cfg(any(target_os = "windows", target_env = "ohos"))]
fn jemalloc_stat(_value_name: &str) -> Option<usize> {
None
}
#[cfg(target_os = "linux")]
fn page_size() -> usize {
unsafe { ::libc::sysconf(::libc::_SC_PAGESIZE) as usize }
}
#[cfg(target_os = "linux")]
fn proc_self_statm_field(field: usize) -> Option<usize> {
use std::fs::File;
use std::io::Read;
let mut f = File::open("/proc/self/statm").ok()?;
let mut contents = String::new();
f.read_to_string(&mut contents).ok()?;
let s = contents.split_whitespace().nth(field)?;
let npages = s.parse::<usize>().ok()?;
Some(npages * page_size())
}
#[cfg(target_os = "linux")]
fn vsize() -> Option<usize> {
proc_self_statm_field(0)
}
#[cfg(target_os = "linux")]
fn resident() -> Option<usize> {
proc_self_statm_field(1)
}
#[cfg(target_os = "macos")]
fn vsize() -> Option<usize> {
virtual_size()
}
#[cfg(target_os = "macos")]
fn resident() -> Option<usize> {
resident_size()
}
#[cfg(not(any(target_os = "linux", target_os = "macos")))]
fn vsize() -> Option<usize> {
None
}
#[cfg(not(any(target_os = "linux", target_os = "macos")))]
fn resident() -> Option<usize> {
None
}
#[cfg(target_os = "linux")]
fn resident_segments() -> Vec<(String, usize)> {
use std::collections::HashMap;
use std::collections::hash_map::Entry;
use std::fs::File;
use std::io::{BufRead, BufReader};
use regex::Regex;
// The first line of an entry in /proc/<pid>/smaps looks just like an entry
// in /proc/<pid>/maps:
//
// address perms offset dev inode pathname
// 02366000-025d8000 rw-p 00000000 00:00 0 [heap]
//
// Each of the following lines contains a key and a value, separated
// by ": ", where the key does not contain either of those characters.
// For example:
//
// Rss: 132 kB
let f = match File::open("/proc/self/smaps") {
Ok(f) => BufReader::new(f),
Err(_) => return vec![],
};
let seg_re = Regex::new(
r"^[:xdigit:]+-[:xdigit:]+ (....) [:xdigit:]+ [:xdigit:]+:[:xdigit:]+ \d+ +(.*)",
)
.unwrap();
let rss_re = Regex::new(r"^Rss: +(\d+) kB").unwrap();
// We record each segment's resident size.
let mut seg_map: HashMap<String, usize> = HashMap::new();
#[derive(PartialEq)]
enum LookingFor {
Segment,
Rss,
}
let mut looking_for = LookingFor::Segment;
let mut curr_seg_name = String::new();
// Parse the file.
for line in f.lines() {
let line = match line {
Ok(line) => line,
Err(_) => continue,
};
if looking_for == LookingFor::Segment {
// Look for a segment info line.
let cap = match seg_re.captures(&line) {
Some(cap) => cap,
None => continue,
};
let perms = cap.get(1).unwrap().as_str();
let pathname = cap.get(2).unwrap().as_str();
// Construct the segment name from its pathname and permissions.
curr_seg_name.clear();
if pathname.is_empty() || pathname.starts_with("[stack:") {
// Anonymous memory. Entries marked with "[stack:nnn]"
// look like thread stacks but they may include other
// anonymous mappings, so we can't trust them and just
// treat them as entirely anonymous.
curr_seg_name.push_str("anonymous");
} else {
curr_seg_name.push_str(pathname);
}
curr_seg_name.push_str(" (");
curr_seg_name.push_str(perms);
curr_seg_name.push(')');
looking_for = LookingFor::Rss;
} else {
// Look for an "Rss:" line.
let cap = match rss_re.captures(&line) {
Some(cap) => cap,
None => continue,
};
let rss = cap.get(1).unwrap().as_str().parse::<usize>().unwrap() * 1024;
if rss > 0 {
// Aggregate small segments into "other".
let seg_name = if rss < 512 * 1024 {
"other".to_owned()
} else {
curr_seg_name.clone()
};
match seg_map.entry(seg_name) {
Entry::Vacant(entry) => {
entry.insert(rss);
},
Entry::Occupied(mut entry) => *entry.get_mut() += rss,
}
}
looking_for = LookingFor::Segment;
}
}
// Note that the sum of all these segments' RSS values differs from the "resident"
// measurement obtained via /proc/<pid>/statm in resident(). It's unclear why this
// difference occurs; for some processes the measurements match, but for Servo they do not.
seg_map.into_iter().collect()
}
#[cfg(not(target_os = "linux"))]
fn resident_segments() -> Vec<(String, usize)> {
vec![]
}