fix(cli): configure v8 isolate with cgroups-constrained memory limit (#29078)

This change configures V8 isolates to respect memory limits imposed by
cgroups on Linux.

It adds support for detecting both cgroups v1 and v2 memory limits,
enabling Deno to properly adapt to containerized environments with
memory constraints. When cgroups information is unavailable or not
applicable, it falls back to using the system's total memory as before.

Closes #29077

## Test

For testing, I created a ubuntu VM with 1Gi memory. Within this VM, set
up a cgroup with 512Mi memory limit, then ran the following script to
see how much heap size limit the V8 isolate had.

```js
import * as v8 from "node:v8";

console.log(v8.getHeapStatistics());
```

### Ubuntu 20.04

In this version of ubuntu, hybrid mode is enabled by default.

```
$ cat /proc/self/cgroup
12:rdma:/
11:blkio:/user.slice
10:devices:/user.slice
9:cpu,cpuacct:/user.slice
8:pids:/user.slice/user-1000.slice/session-3.scope
7:memory:/user.slice/user-1000.slice/session-3.scope
6:perf_event:/
5:freezer:/
4:net_cls,net_prio:/
3:hugetlb:/
2:cpuset:/
1:name=systemd:/user.slice/user-1000.slice/session-3.scope
0::/user.slice/user-1000.slice/session-3.scope
```

Create a new cgroup with 512Mi memory limit and run the above script in
this cgroup:

```
$ sudo cgcreate -g memory:/mygroup
$ sudo cgset -r memory.limit_in_bytes=$((512 * 1024 * 1024)) mygroup
$ sudo cgexec -g memory:mygroup ./deno run main.mjs
{
  total_heap_size: 7745536,
  total_heap_size_executable: 0,
  total_physical_size: 7090176,
  total_available_size: 266348216,
  used_heap_size: 6276752,
  heap_size_limit: 271581184,
  malloced_memory: 303200,
  peak_malloced_memory: 140456,
  does_zap_garbage: 0,
  number_of_native_contexts: 1,
  number_of_detached_contexts: 0,
  total_global_handles_size: 24576,
  used_global_handles_size: 22432,
  external_memory: 3232012
}
```

This indicates that the isolate was informed of cgroup-constrained
memory limit (512Mi) and hence got ~270M heap limit.

### Ubuntu 22.04

In this version of ubuntu, cgroup v2 is used.

```
$ cat /proc/self/cgroup
0::/user.slice/user-1000.slice/session-3.scope
```

Run the above script using `systemd-run`:

```
$ sudo systemd-run --property=MemoryMax=512M --pty bash -c '/home/ubuntu/deno run /home/ubuntu/main.mjs'
{
  total_heap_size: 7745536,
  total_heap_size_executable: 0,
  total_physical_size: 7090176,
  total_available_size: 266348184,
  used_heap_size: 6276784,
  heap_size_limit: 271581184,
  malloced_memory: 303200,
  peak_malloced_memory: 140456,
  does_zap_garbage: 0,
  number_of_native_contexts: 1,
  number_of_detached_contexts: 0,
  total_global_handles_size: 24576,
  used_global_handles_size: 22432,
  external_memory: 3232012
}
```

Again the isolate got ~270M heap limit properly.
Note that it should have had bigger heap limit if the entire system
memory, i.e. 1Gi, had been passed to V8. In fact, if we run the same
script outside the cgroup, it does display larger `heap_size_limit` like
below:

```
$ ./deno run main.mjs
{
  total_heap_size: 7745536,
  total_heap_size_executable: 0,
  total_physical_size: 7090176,
  total_available_size: 546580152,
  used_heap_size: 6276752,
  heap_size_limit: 551813120,
  malloced_memory: 303200,
  peak_malloced_memory: 140456,
  does_zap_garbage: 0,
  number_of_native_contexts: 1,
  number_of_detached_contexts: 0,
  total_global_handles_size: 24576,
  used_global_handles_size: 22432,
  external_memory: 3232012
}
```

---------

Signed-off-by: Yusuke Tanaka <wing0920@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
This commit is contained in:
Yusuke Tanaka 2025-05-14 00:07:59 +09:00 committed by GitHub
parent 6002d2624e
commit 9b2b1c41f5
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6 changed files with 172 additions and 13 deletions

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@ -3921,7 +3921,7 @@ impl Inner {
}
#[cfg_attr(feature = "lsp-tracing", tracing::instrument(skip_all))]
fn project_changed<'a>(
fn project_changed(
&mut self,
changed_specifiers: impl IntoIterator<Item = (Arc<Url>, ChangeKind)>,
scopes_change: ProjectScopesChange,