Re: [PATCH 2/6] block/nvme: convert to blk_io_plug_call() API

[Stefano Garzarella]

On Wed, May 17, 2023 at 06:10:18PM -0400, Stefan Hajnoczi wrote:
> Stop using the .bdrv_co_io_plug() API because it is not multi-queue
> block layer friendly. Use the new blk_io_plug_call() API to batch I/O
> submission instead.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> block/nvme.c | 44 ++++++++++++--------------------------------
> 1 file changed, 12 insertions(+), 32 deletions(-)
>
> diff --git a/block/nvme.c b/block/nvme.c
> index 5b744c2bda..100b38b592 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c
> @@ -25,6 +25,7 @@
> #include "qemu/vfio-helpers.h"
> #include "block/block-io.h"
> #include "block/block_int.h"
> +#include "sysemu/block-backend.h"
> #include "sysemu/replay.h"
> #include "trace.h"
>
> @@ -119,7 +120,6 @@ struct BDRVNVMeState {
>     int blkshift;
>
>     uint64_t max_transfer;
> -    bool plugged;
>
>     bool supports_write_zeroes;
>     bool supports_discard;
> @@ -282,7 +282,7 @@ static void nvme_kick(NVMeQueuePair *q)
> {
>     BDRVNVMeState *s = q->s;
>
> -    if (s->plugged || !q->need_kick) {
> +    if (!q->need_kick) {
>         return;
>     }
>     trace_nvme_kick(s, q->index);
> @@ -387,10 +387,6 @@ static bool nvme_process_completion(NVMeQueuePair *q)
>     NvmeCqe *c;
>
>     trace_nvme_process_completion(s, q->index, q->inflight);
> -    if (s->plugged) {
> -        trace_nvme_process_completion_queue_plugged(s, q->index);

Should we remove "nvme_process_completion_queue_plugged(void *s,
unsigned q_index) "s %p q #%u" from block/trace-events?

The rest LGTM!

Thanks,
Stefano