Re: [Qemu-devel] [BUG?] aio_get_linux_aio: Assertion `ctx->linux_aio' failed

[Farhan Ali <alifm@linux.ibm.com>]

On 07/17/2018 04:52 PM, Nishanth Aravamudan wrote:
> iiuc, this possibly implies AIO was not actually used previously on this
> guest (it might have silently been falling back to threaded IO?). I
> don't have access to s390x, but would it be possible to run qemu under
> gdb and see if aio_setup_linux_aio is being called at all (I think it
> might not be, but I'm not sure why), and if so, if it's for the context
> in question?
> 
> If it's not being called first, could you see what callpath is calling
> aio_get_linux_aio when this assertion trips?
> 
> Thanks!
> -Nish


Hi Nishant,

 From the coredump of the guest this is the call trace that calls 
aio_get_linux_aio:


Stack trace of thread 145158:
#0  0x000003ff94dbe274 raise (libc.so.6)
#1  0x000003ff94da39a8 abort (libc.so.6)
#2  0x000003ff94db62ce __assert_fail_base (libc.so.6)
#3  0x000003ff94db634c __assert_fail (libc.so.6)
#4  0x000002aa20db067a aio_get_linux_aio (qemu-system-s390x)
#5  0x000002aa20d229a8 raw_aio_plug (qemu-system-s390x)
#6  0x000002aa20d309ee bdrv_io_plug (qemu-system-s390x)
#7  0x000002aa20b5a8ea virtio_blk_handle_vq (qemu-system-s390x)
#8  0x000002aa20db2f6e aio_dispatch_handlers (qemu-system-s390x)
#9  0x000002aa20db3c34 aio_poll (qemu-system-s390x)
#10 0x000002aa20be32a2 iothread_run (qemu-system-s390x)
#11 0x000003ff94f879a8 start_thread (libpthread.so.0)
#12 0x000003ff94e797ee thread_start (libc.so.6)


Thanks for taking a look and responding.

Thanks
Farhan