Am 26.10.21 um 16:53 schrieb Peter Lieven:
Am 25.10.21 um 14:58 schrieb Kevin Wolf:
Am 25.10.2021 um 13:39 hat Peter Lieven geschrieben:
Am 16.09.21 um 14:34 schrieb Peter Lieven:
Am 09.07.21 um 12:21 schrieb Kevin Wolf:
Am 08.07.2021 um 20:23 hat Peter Lieven geschrieben:
Am 08.07.2021 um 14:18 schrieb Kevin Wolf <kw...@redhat.com>:
Am 07.07.2021 um 20:13 hat Peter Lieven geschrieben:
Am 06.07.2021 um 17:25 schrieb Kevin Wolf <kw...@redhat.com>:
Am 06.07.2021 um 16:55 hat Peter Lieven geschrieben:
I will have a decent look after my vacation.
Sounds good, thanks. Enjoy your vacation!
As I had to fire up my laptop to look into another issue anyway, I
have sent two patches for updating MAINTAINERS and to fix the int vs.
bool mix for task->complete.
I think you need to reevaluate your definition of vacation. ;-)
Lets talk about this when the kids are grown up. Sometimes sending
patches can be quite relaxing :-)
Heh, fair enough. :-)
But thanks anyway.
As Paolos fix (5f50be9b5) is relatively new and there are maybe other
non obvious problems when removing the BH indirection and we are close
to soft freeze I would leave the BH removal change for 6.2.
Sure, code cleanups aren't urgent.
Isn’t the indirection also a slight performance drop?
Yeah, I guess technically it is, though I doubt it's measurable.
As promised I was trying to remove the indirection through the BH after Qemu
6.1 release.
However, if I remove the BH I run into the following assertion while running
some fio tests:
qemu-system-x86_64: ../block/block-backend.c:1197: blk_wait_while_drained: Assertion
`blk->in_flight > 0' failed.
Any idea?
This is what I changed:
diff --git a/block/rbd.c b/block/rbd.c
index 3cb24f9981..bc1dbc20f7 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1063,13 +1063,6 @@ static int qemu_rbd_resize(BlockDriverState *bs,
uint64_t size)
return 0;
}
-static void qemu_rbd_finish_bh(void *opaque)
-{
- RBDTask *task = opaque;
- task->complete = true;
- aio_co_wake(task->co);
-}
-
/*
* This is the completion callback function for all rbd aio calls
* started from qemu_rbd_start_co().
@@ -1083,8 +1076,8 @@ static void qemu_rbd_completion_cb(rbd_completion_t c,
RBDTask *task)
{
task->ret = rbd_aio_get_return_value(c);
rbd_aio_release(c);
- aio_bh_schedule_oneshot(bdrv_get_aio_context(task->bs),
- qemu_rbd_finish_bh, task);
+ task->complete = true;
+ aio_co_wake(task->co);
}
Kevin, Paolo, any idea?
Not really, I don't see the connection between both places.
Do you have a stack trace for the crash?
The crash seems not to be limited to that assertion. I have also seen:
qemu-system-x86_64: ../block/block-backend.c:1497: blk_aio_write_entry: Assertion
`!qiov || qiov->size == acb->bytes' failed.
Altough harder to trigger I catch this backtrace in gdb:
qemu-system-x86_64: ../block/block-backend.c:1497: blk_aio_write_entry: Assertion
`!qiov || qiov->size == acb->bytes' failed.
[Wechseln zu Thread 0x7ffff7fa8f40 (LWP 17852)]
Thread 1 "qemu-system-x86" hit Breakpoint 1, __GI_abort () at abort.c:49
49 abort.c: Datei oder Verzeichnis nicht gefunden.
(gdb) bt
#0 0x00007ffff42567e0 in __GI_abort () at abort.c:49
#1 0x00007ffff424648a in __assert_fail_base (fmt=0x7ffff43cd750 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",
assertion=assertion@entry=0x555555e638e0 "!qiov || qiov->size == acb->bytes", file=file@entry=0x555555e634b2
"../block/block-backend.c", line=line@entry=1497, function=function@entry=0x555555e63b20
<__PRETTY_FUNCTION__.32450> "blk_aio_write_entry") at assert.c:92
#2 0x00007ffff4246502 in __GI___assert_fail (assertion=assertion@entry=0x555555e638e0 "!qiov || qiov->size ==
acb->bytes", file=file@entry=0x555555e634b2 "../block/block-backend.c", line=line@entry=1497,
function=function@entry=0x555555e63b20 <__PRETTY_FUNCTION__.32450> "blk_aio_write_entry") at assert.c:101
#3 0x0000555555becc78 in blk_aio_write_entry (opaque=0x555556b534f0) at
../block/block-backend.c:1497
#4 0x0000555555cf0e4c in coroutine_trampoline (i0=<optimized out>, i1=<optimized
out>) at ../util/coroutine-ucontext.c:173
#5 0x00007ffff426e7b0 in __start_context () at /lib/x86_64-linux-gnu/libc.so.6
#6 0x00007fffffffd5a0 in ()
#7 0x0000000000000000 in ()
any ideas? Or should we just abandon the idea of removing the BH?
Peter