On 02.01.24 16:24, Hanna Czenczek wrote:
[...]
I’ve attached the preliminary patch that I didn’t get to send (or test
much) last year. Not sure if it has the same CPU-usage-spike issue
Fiona was seeing, the only functional difference is that I notify the
vq after attaching the notifiers instead of before.
It’ll take me some more time to send a patch mail to that effect,
because now there’s an assertion failure on hotunplug, which bisects
back to eaad0fe26050c227dc5dad63205835bac4912a51 (“scsi: only access
SCSIDevice->requests from one thread”):
{"execute":"device_del","arguments":{"id":"stg0"}}
{"return": {}}
qemu-system-x86_64: ../block/block-backend.c:2429: blk_get_aio_context:
Assertion `ctx == blk->ctx' failed.
(gdb) bt
#0 0x00007f32a668d83c in () at /usr/lib/libc.so.6
#1 0x00007f32a663d668 in raise () at /usr/lib/libc.so.6
#2 0x00007f32a66254b8 in abort () at /usr/lib/libc.so.6
#3 0x00007f32a66253dc in () at /usr/lib/libc.so.6
#4 0x00007f32a6635d26 in () at /usr/lib/libc.so.6
#5 0x0000556e6b4880a4 in blk_get_aio_context (blk=0x556e6e89ccf0) at
../block/block-backend.c:2429
#6 blk_get_aio_context (blk=0x556e6e89ccf0) at
../block/block-backend.c:2417
#7 0x0000556e6b112d87 in scsi_device_for_each_req_async_bh
(opaque=0x556e6e2c6d10) at ../hw/scsi/scsi-bus.c:128
#8 0x0000556e6b5d1966 in aio_bh_poll (ctx=ctx@entry=0x556e6d8aa290) at
../util/async.c:218
#9 0x0000556e6b5bb16a in aio_poll (ctx=0x556e6d8aa290,
blocking=blocking@entry=true) at ../util/aio-posix.c:722
#10 0x0000556e6b4564b6 in iothread_run
(opaque=opaque@entry=0x556e6d89d920) at ../iothread.c:63
#11 0x0000556e6b5bde58 in qemu_thread_start (args=0x556e6d8aa9b0) at
../util/qemu-thread-posix.c:541
#12 0x00007f32a668b9eb in () at /usr/lib/libc.so.6
#13 0x00007f32a670f7cc in () at /usr/lib/libc.so.6
