Am 28.10.2025 um 17:33 hat Hanna Czenczek geschrieben:
> nvme_process_completion() must run in the main BDS context, so schedule
> a BH for requests that aren’t there.
>
> The context in which we kick does not matter, but let’s just keep kick
> and process_completion together for simplicity’s sake.
Ok, fair, move the main BDS context for calling these functions. But
doesn't that mean that we need to move back to the request context for
calling the callback?
In particular, I see this:
static void nvme_rw_cb_bh(void *opaque)
{
NVMeCoData *data = opaque;
qemu_coroutine_enter(data->co);
}
The next patch changes some things about coroutine wakeup, but it
doesn't touch this qemu_coroutine_enter(). So I think the coroutine is
now running in the wrong thread.
I also feel that it gets a bit confusing what is running in which
context, so maybe we can add comments to each of the callbacks telling
that they are running in main BDS context or request coroutine context.
> (For what it’s worth, a quick fio bandwidth test indicates that on my
> test hardware, if anything, this may be a bit better than kicking
> immediately before scheduling a pure nvme_process_completion() BH. But
> I wouldn’t take more from those results than that it doesn’t really seem
> to matter either way.)
>
> Cc: [email protected]
> Signed-off-by: Hanna Czenczek <[email protected]>
Kevin
