On Tue, 14 Jan 2020, Michael Tokarev wrote:
Can you please try one more thing here, - namely, getting a backtrace?
Qemu being unresponsible means it is the main thread which is blocked,
so getting a backtrace should be easy - please install the qemu-system-x86
debug package (after adding something like this to sources.list:
deb http://deb.debian.org/debian-debug/ stable-debug main
, see https://wiki.debian.org/AutomaticDebugPackages), and get a backtrace
using gdb, like this:
gdb /usr/bin/qemu-system-x86_64 -p <pid-of-the-qemu-process>
and do a `bt' command in there, posting the results from it.
Thank you!
Of course, should've thought of that myself actually :)
(gdb) bt
#0 0x000055adc699e86c in conv_natural_int16_t_to_stereo (dst=<optimized out>,
src=<optimized out>, samples=<optimized out>)
at ./audio/mixeng_template.h:110
#1 0x000055adc699b4b9 in audio_pcm_hw_run_in (samples=18446744048139465969,
hw=0x55adca24ec20) at ./audio/audio.c:1249
#2 0x000055adc699b4b9 in audio_run_in (s=0x55adca249330) at
./audio/audio.c:1280
#3 0x000055adc699b4b9 in audio_run (s=0x55adca249330, msg=msg@entry=0x55adc6d04098
"alsa run (running)") at ./audio/audio.c:1355
#4 0x000055adc69a0988 in alsa_poll_handler (opaque=0x55adca24ecc0) at
./audio/alsaaudio.c:203
#5 0x000055adc6c93ed7 in aio_dispatch_handlers (ctx=ctx@entry=0x55adc92400c0)
at ./util/aio-posix.c:429
#6 0x000055adc6c948a8 in aio_dispatch (ctx=0x55adc92400c0) at
./util/aio-posix.c:460
#7 0x000055adc6c9117e in aio_ctx_dispatch (source=<optimized out>, callback=<optimized
out>, user_data=<optimized out>) at ./util/async.c:260
#8 0x00007f99c123df1d in g_main_context_dispatch () at
/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#9 0x000055adc6c93948 in glib_pollfds_poll () at ./util/main-loop.c:219
#10 0x000055adc6c93948 in os_host_main_loop_wait (timeout=<optimized out>) at
./util/main-loop.c:242
#11 0x000055adc6c93948 in main_loop_wait (nonblocking=<optimized out>) at
./util/main-loop.c:518
#12 0x000055adc6994e0e in main_loop () at ./vl.c:1810
#13 0x000055adc67fb0c9 in main (argc=<optimized out>, argv=<optimized out>,
envp=<optimized out>) at ./vl.c:4466
(gdb)
I also forgot to note down some other important information, namely the
commandline options and config plus few quite related environment
variables .. the commandline is
qemu-system-x86_64 --enable-kvm -readconfig test.config
-soundhw hda -vga qxl -display gtk
contents of test.config attached.
I have the following environment variables set in my script that runs qemu:
export QEMU_AUDIO_DAC_TRY_POLL=0
export QEMU_AUDIO_DRV="alsa"
export QEMU_ALSA_ADC_DEV="null"
That DAC_TRY_POLL=0 was essential to get things working with dmix, DRV
is obvious, ADC I've set just null because I'm not using mic or anything.
Hopefully this helps. I should probably fiddle around and test some more,
but have been a bit busy with other things.
--
] ccr/TNSP ^ pWp :: c...@tnsp.org :: https://tnsp.org/~ccr/
] https://tnsp.org/hg/ -- https://www.openhub.net/accounts/ccr
] PGP key: 7BED 62DE 898D D1A4 FC4A F392 B705 E735 307B AAE3
# qemu config file
[drive]
driver = "raw"
file = "/misc/virtual/test.img"
if = "virtio"
[device]
driver = "usb-tablet"
[nic]
type = "user"
model = "virtio-net-pci"
[rtc]
base = "localtime"
clock = "host"
[machine]
accel = "kvm"
usb = "on"
[memory]
size = "12G"
[smp-opts]
cpus = "8"
sockets = "1"
cores = "4"
threads = "2"
