On 24/12/2021 10:37, Rao, Lei wrote:
> This patch is to improve the logic of QEMU main thread sleep code in
> qemu_chr_write_buffer() where it can be blocked and can't run other
> coroutines during COLO IO stress test.
>
> Our approach is to put filter_send() in a coroutine. In this way,
> filter_send() will call qemu_coroutine_yield() in qemu_co_sleep_ns(),
> so that it can be scheduled out and QEMU main thread has opportunity to
> run other tasks.
>
> Signed-off-by: Lei Rao <lei....@intel.com>
> Signed-off-by: Zhang Chen <chen.zh...@intel.com>
> ---
> net/filter-mirror.c | 67 ++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 54 insertions(+), 13 deletions(-)
>
> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> index f20240cc9f..1e9f8b6216 100644
> --- a/net/filter-mirror.c
> +++ b/net/filter-mirror.c
> @@ -20,6 +20,7 @@
> #include "chardev/char-fe.h"
> #include "qemu/iov.h"
> #include "qemu/sockets.h"
> +#include "block/aio-wait.h"
>
> #define TYPE_FILTER_MIRROR "filter-mirror"
> typedef struct MirrorState MirrorState;
> @@ -42,20 +43,21 @@ struct MirrorState {
> bool vnet_hdr;
> };
>
> -static int filter_send(MirrorState *s,
> - const struct iovec *iov,
> - int iovcnt)
> +typedef struct FilterSendCo {
> + MirrorState *s;
> + char *buf;
> + ssize_t size;
> + bool done;
> + int ret;
> +} FilterSendCo;
> +
> +static int _filter_send(MirrorState *s,
> + char *buf,
> + ssize_t size)
> {
> NetFilterState *nf = NETFILTER(s);
> int ret = 0;
> - ssize_t size = 0;
> uint32_t len = 0;
> - char *buf;
> -
> - size = iov_size(iov, iovcnt);
> - if (!size) {
> - return 0;
> - }
>
> len = htonl(size);
> ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, sizeof(len));
> @@ -80,10 +82,7 @@ static int filter_send(MirrorState *s,
> }
> }
>
> - buf = g_malloc(size);
> - iov_to_buf(iov, iovcnt, 0, buf, size);
> ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)buf, size);
> - g_free(buf);
> if (ret != size) {
> goto err;
> }
> @@ -94,6 +93,48 @@ err:
> return ret < 0 ? ret : -EIO;
> }
>
> +static void coroutine_fn filter_send_co(void *opaque)
> +{
> + FilterSendCo *data = opaque;
> +
> + data->ret = _filter_send(data->s, data->buf, data->size);
> + data->done = true;
> + g_free(data->buf);
> + aio_wait_kick();
> +}
> +
> +static int filter_send(MirrorState *s,
> + const struct iovec *iov,
> + int iovcnt)
> +{
> + ssize_t size = iov_size(iov, iovcnt);
> + char *buf = NULL;
> +
> + if (!size) {
> + return 0;
> + }
> +
> + buf = g_malloc(size);
> + iov_to_buf(iov, iovcnt, 0, buf, size);
> +
> + FilterSendCo data = {
> + .s = s,
> + .size = size,
> + .buf = buf,
> + .ret = 0,
> + };
> +
> + Coroutine *co = qemu_coroutine_create(filter_send_co, &data);
BTW, does qemu/old gcc complaint such coding style ?
int a;
a = foo()
int b = a;
> + qemu_coroutine_enter(co);
> +
> + while (!data.done) {
> + aio_poll(qemu_get_aio_context(), true);
> + }
> +
> + return data.ret;
> +
redundant newline
Otherwise,
Reviewed-by: Li Zhijian <lizhij...@fujitsu.com>
> +}
> +
> static void redirector_to_filter(NetFilterState *nf,
> const uint8_t *buf,
> int len)
