Re: [Qemu-devel] pthread_create failed: Resource temporarily unavailable

[Stefan Hajnoczi]

On Wed, Jan 2, 2013 at 8:17 PM, Christoffer Dall <address@hidden> wrote:
> I am seeing some brutal crashes with QEMU running virtio using KVM/ARM.
>
> The culprit seems to be when the process runs out of virtual address
> space on 32-bit systems due to some subsystem (virtio?) creating a
> large number of pthreads under heavy workloads.

It would be interesting to see the resource utilization at the point
of failure - virtual memory, number of threads, etc.

> Unfortunately my QEMU expertise is too limited to pin-point the exact
> fix, nor do I have resources right now to go into it, but I wanted to
> raise this issue and spread general awareness.
>
> Is this a known issue or something that needs to be tracked/documented at 
> least?

If you launch QEMU under gdb it will break when qemu_thread_create()
fails to create a new thread.

This may be coming from thread-pool.c:do_spawn_thread().  It shouldn't
be a fatal error since eventually an existing worker thread will
process the queued work.

Please post the backtrace so it's clear where QEMU hits the failure.

Stefan