Commit bf25285f authored 6 years ago by Héctor Orón Martínez

worker: override DefaultTasksMax


The following error
```
[   67s] Unpacking gcc-7 (7.3.0-16ubuntu3) ...
[   67s] dpkg-deb: unrecoverable fatal error, aborting:
[   67s]  fork failed: Resource temporarily unavailable
[   67s] dpkg: error processing archive /var/cache/apt/archives/gcc-7_7.3.0-16ubuntu3_i386.deb (--unpack):
[   67s]  dpkg-deb --fsys-tarfile subprocess returned error exit status 2
[   67s] dpkg: unrecoverable fatal error, aborting:
[   67s]  fork failed: Resource temporarily unavailable
[   67s] /usr/sbin/debootstrap: 996: /usr/sbin/debootstrap: Cannot fork
[...]
```

happens since all builds happen in the same cgroup which is limited to 4915,
while builds have NPROC rlimits (just over 64000). If it reaches a total of
4915 tasks (processes and threads) calls like `fork()`, `clone()`,
`pthread_create()` will fail.

This is a short term fix proposed by Simon McVittie, while the long term
solution should place each `bs_worker` instance in its own systemd-managed
cgroup. The default task limit of 4915 might then be adequated.

Signed-off-by: Héctor Orón Martínez <hector.oron@collabora.com>