Patchwork [v3,4/9] Store the data to send also in iovec

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Submitter Orit Wasserman
Date March 21, 2013, 4:05 p.m.
Message ID <1363881940-27505-5-git-send-email-owasserm@redhat.com>
Download mbox | patch
Permalink /patch/229760/
State New
Headers show

Comments

Orit Wasserman - March 21, 2013, 4:05 p.m.
All data is still copied into the static buffer.

Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
 savevm.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
Juan Quintela - March 21, 2013, 5:11 p.m.
Orit Wasserman <owasserm@redhat.com> wrote:
> All data is still copied into the static buffer.
>
> Signed-off-by: Orit Wasserman <owasserm@redhat.com>
> ---
>  savevm.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/savevm.c b/savevm.c
> index 686c8c8..ab81dd3 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -114,6 +114,7 @@ void qemu_announce_self(void)
>  /* savevm/loadvm support */
>  
>  #define IO_BUF_SIZE 32768
> +#define MAX_IOV_SIZE MIN(IOV_MAX, 64)
>  
>  struct QEMUFile {
>      const QEMUFileOps *ops;
> @@ -129,6 +130,9 @@ struct QEMUFile {
>      int buf_size; /* 0 when writing */
>      uint8_t buf[IO_BUF_SIZE];
>  
> +    struct iovec iov[MAX_IOV_SIZE];
> +    unsigned int iovcnt;
> +
>      int last_error;
>  };
>  
> @@ -527,6 +531,7 @@ static void qemu_fflush(QEMUFile *f)
>              f->pos += f->buf_index;
>          }
>          f->buf_index = 0;
> +        f->iovcnt = 0;
>      }
>      if (ret < 0) {
>          qemu_file_set_error(f, ret);
> @@ -619,12 +624,14 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
>          if (l > size)
>              l = size;
>          memcpy(f->buf + f->buf_index, buf, l);
> +        f->iov[f->iovcnt].iov_base = f->buf + f->buf_index;
> +        f->iov[f->iovcnt++].iov_len = l;
>          f->is_write = 1;
>          f->buf_index += l;
>          f->bytes_xfer += l;

After reading the patch several times, we need to do a s/l/len/ on this
function, 1 and l are too similar, and I was reading the wrong value :p

>          buf += l;
>          size -= l;
> -        if (f->buf_index >= IO_BUF_SIZE) {
> +        if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
>              qemu_fflush(f);
>              if (qemu_file_get_error(f)) {
>                  break;
> @@ -648,8 +655,10 @@ void qemu_put_byte(QEMUFile *f, int v)
>      f->buf[f->buf_index++] = v;
>      f->is_write = 1;
>      f->bytes_xfer += 1;
> +    f->iov[f->iovcnt].iov_base = f->buf + (f->buf_index - 1);
> +    f->iov[f->iovcnt++].iov_len = 1;
>  
> -    if (f->buf_index >= IO_BUF_SIZE) {
> +    if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
>          qemu_fflush(f);
>      }
>  }

Reviewed-by: Juan Quintela <quintela@redhat.com>

Patch

diff --git a/savevm.c b/savevm.c
index 686c8c8..ab81dd3 100644
--- a/savevm.c
+++ b/savevm.c
@@ -114,6 +114,7 @@  void qemu_announce_self(void)
 /* savevm/loadvm support */
 
 #define IO_BUF_SIZE 32768
+#define MAX_IOV_SIZE MIN(IOV_MAX, 64)
 
 struct QEMUFile {
     const QEMUFileOps *ops;
@@ -129,6 +130,9 @@  struct QEMUFile {
     int buf_size; /* 0 when writing */
     uint8_t buf[IO_BUF_SIZE];
 
+    struct iovec iov[MAX_IOV_SIZE];
+    unsigned int iovcnt;
+
     int last_error;
 };
 
@@ -527,6 +531,7 @@  static void qemu_fflush(QEMUFile *f)
             f->pos += f->buf_index;
         }
         f->buf_index = 0;
+        f->iovcnt = 0;
     }
     if (ret < 0) {
         qemu_file_set_error(f, ret);
@@ -619,12 +624,14 @@  void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
         if (l > size)
             l = size;
         memcpy(f->buf + f->buf_index, buf, l);
+        f->iov[f->iovcnt].iov_base = f->buf + f->buf_index;
+        f->iov[f->iovcnt++].iov_len = l;
         f->is_write = 1;
         f->buf_index += l;
         f->bytes_xfer += l;
         buf += l;
         size -= l;
-        if (f->buf_index >= IO_BUF_SIZE) {
+        if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
             qemu_fflush(f);
             if (qemu_file_get_error(f)) {
                 break;
@@ -648,8 +655,10 @@  void qemu_put_byte(QEMUFile *f, int v)
     f->buf[f->buf_index++] = v;
     f->is_write = 1;
     f->bytes_xfer += 1;
+    f->iov[f->iovcnt].iov_base = f->buf + (f->buf_index - 1);
+    f->iov[f->iovcnt++].iov_len = 1;
 
-    if (f->buf_index >= IO_BUF_SIZE) {
+    if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
         qemu_fflush(f);
     }
 }