Re: [Qemu-devel] qemu 1.6.1

[Stefan Weil]

Am 27.10.2013 07:54, schrieb Paolo Bonzini:
>
> I think the problem is that 0x20(%esp) gets somehow corrupted at the
> instruction I highlighted with **.
>
> The simplest fix then would be to add a barrier() before and after
> SwitchToFiber.
>
> Paolo

I added some debugging output (see code at
http://qemu.weilnetz.de/test/coroutine-win32/). The result with pointer
values replaced by function names is shown below.

There are two threads (WinMain, qemu_tcg_cpu_thread_fn) and one
coroutine (bdrv_rw_co_entry).

Stefan


qemu_coroutine_self:WinMain
qemu_in_coroutine:WinMain,null
qemu_coroutine_new:bdrv_rw_co_entry
qemu_coroutine_create,co=bdrv_rw_co_entry
qemu_coroutine_enter(bdrv_rw_co_entry,...),self=WinMain
coroutine_swap(WinMain,bdrv_rw_co_entry)
qemu_coroutine_yield,self=bdrv_rw_co_entry,to=WinMain
coroutine_swap(bdrv_rw_co_entry,WinMain)
qemu_coroutine_enter(bdrv_rw_co_entry,...),self=WinMain
coroutine_swap(WinMain,bdrv_rw_co_entry)
qemu_in_coroutine:bdrv_rw_co_entry,WinMain
# active coroutine bdrv_rw_co_entry is deleted
coroutine_delete(bdrv_rw_co_entry)
qemu_coroutine_self:qemu_tcg_cpu_thread_fn
qemu_in_coroutine:qemu_tcg_cpu_thread_fn,null
qemu_coroutine_create,co=bdrv_rw_co_entry
qemu_coroutine_enter(bdrv_rw_co_entry,...),self=qemu_tcg_cpu_thread_fn
coroutine_swap(qemu_tcg_cpu_thread_fn,bdrv_rw_co_entry)
qemu_coroutine_yield,self=bdrv_rw_co_entry,to=qemu_tcg_cpu_thread_fn
coroutine_swap(bdrv_rw_co_entry,qemu_tcg_cpu_thread_fn)
qemu_coroutine_enter(bdrv_rw_co_entry,...),self=qemu_tcg_cpu_thread_fn
coroutine_swap(qemu_tcg_cpu_thread_fn,bdrv_rw_co_entry)
qemu_in_coroutine:bdrv_rw_co_entry,qemu_tcg_cpu_thread_fn
qemu_in_coroutine:bdrv_rw_co_entry,qemu_tcg_cpu_thread_fn
# active coroutine bdrv_rw_co_entry is deleted
coroutine_delete(bdrv_rw_co_entry)
# now we are still in deleted coroutine bdrv_rw_co_entry
qemu_in_coroutine:bdrv_rw_co_entry,null
qemu_coroutine_create,co=bdrv_rw_co_entry
qemu_coroutine_enter(bdrv_rw_co_entry,...),self=bdrv_rw_co_entry
coroutine_swap(bdrv_rw_co_entry,bdrv_rw_co_entry)
qemu_coroutine_yield,self=bdrv_rw_co_entry,to=bdrv_rw_co_entry
coroutine_swap(bdrv_rw_co_entry,bdrv_rw_co_entry)
qemu_in_coroutine:bdrv_rw_co_entry,null