Re: [PATCH v2] net/filter: Optimize filter_send to coroutine

[Jason Wang <jasowang@redhat.com>]

On Mon, Dec 27, 2021 at 10:14 AM Zhang, Chen <chen.zhang@intel.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Rao, Lei <lei.rao@intel.com>
> > Sent: Monday, December 27, 2021 9:20 AM
> > To: Zhang, Chen <chen.zhang@intel.com>; lizhijian@cn.fujitsu.com;
> > jasowang@redhat.com
> > Cc: qemu-devel@nongnu.org; Rao, Lei <lei.rao@intel.com>; Li Zhijian
> > <lizhijian@fujitsu.com>
> > Subject: [PATCH v2] net/filter: Optimize filter_send to coroutine
> >
> > 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.rao@intel.com>
> > Signed-off-by: Zhang Chen <chen.zhang@intel.com>
> > Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
>
> Looks good to me.
> Reviewed-by: Zhang Chen <chen.zhang@intel.com>

Applied.

Thanks

>
> Thanks
> Chen
>
> > ---
> >  net/filter-mirror.c | 66 ++++++++++++++++++++++++++++++++++++--------
> > -
> >  1 file changed, 53 insertions(+), 13 deletions(-)
> >
> > diff --git a/net/filter-mirror.c b/net/filter-mirror.c index
> > f20240cc9f..34a63b5dbb 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 +93,47 @@ 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);
> > +    qemu_coroutine_enter(co);
> > +
> > +    while (!data.done) {
> > +        aio_poll(qemu_get_aio_context(), true);
> > +    }
> > +
> > +    return data.ret;
> > +}
> > +
> >  static void redirector_to_filter(NetFilterState *nf,
> >                                   const uint8_t *buf,
> >                                   int len)
> > --
> > 2.32.0
>