Re: [Qemu-devel] [RFC 10/12] Add qemu_put_buffer_no_copy

[Paolo Bonzini]

Il 21/03/2013 10:09, Orit Wasserman ha scritto:
> +    f->iov[f->iovcnt].iov_base = (uint8_t *)buf;
> +    f->iov[f->iovcnt++].iov_len = size;
> +
> +    f->is_write = 1;
> +    f->bytes_xfer += size;
> +
> +    if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
> +        qemu_fflush(f);
>      }

It should not be complex to check if f->iov[f->iovcnt - 1] can be
extended?  This could remove many system calls when you have many
consecutive zero pages.

Paolo