[CRIU] [PATCH 03/11] pagemap: Enqueue iovec to some list

[Mike Rapoport]

On Fri, May 05, 2017 at 07:02:15PM +0300, Pavel Emelyanov wrote:
> pagemap: Enqueue iovec to some list

Maybe "pagemap: allow to enqueue iovec to arbitrary list"?

> We currently can batch pagemap entries into page-read list, but will
> need to queue them into per-pstree_entry one.
> 
> Signed-off-by: Pavel Emelyanov <xemul at virtuozzo.com>
> ---
>  criu/include/pagemap.h |  3 +++
>  criu/pagemap.c         | 19 ++++++++++---------
>  2 files changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/criu/include/pagemap.h b/criu/include/pagemap.h
> index b23ec3a..aa3c4aa 100644
> --- a/criu/include/pagemap.h
> +++ b/criu/include/pagemap.h
> @@ -104,6 +104,9 @@ extern int open_page_read(int pid, struct page_read *, int pr_flags);
>  extern int open_page_read_at(int dfd, int pid, struct page_read *pr,
>  		int pr_flags);
> 
> +int pagemap_enqueue_iovec(struct page_read *pr, void *buf,
> +			      unsigned long len, struct list_head *to);
> +
>  /*
>   * Create a shallow copy of page_read object.
>   * The new object shares the pagemap structures with the original, but
> diff --git a/criu/pagemap.c b/criu/pagemap.c
> index 2cf91e3..dcc1332 100644
> --- a/criu/pagemap.c
> +++ b/criu/pagemap.c
> @@ -279,7 +279,8 @@ static int read_local_page(struct page_read *pr, unsigned long vaddr,
>  	return 0;
>  }
> 
> -static int enqueue_async_iov(struct page_read *pr, unsigned long len, void *buf)
> +static int enqueue_async_iov(struct page_read *pr, void *buf,
> +		unsigned long len, struct list_head *to)
>  {
>  	struct page_read_iov *pr_iov;
>  	struct iovec *iov;
> @@ -303,19 +304,19 @@ static int enqueue_async_iov(struct page_read *pr, unsigned long len, void *buf)
>  	pr_iov->to = iov;
>  	pr_iov->nr = 1;
> 
> -	list_add_tail(&pr_iov->l, &pr->async);
> +	list_add_tail(&pr_iov->l, to);
> 
>  	return 0;
>  }
> 
> -static int enqueue_async_page(struct page_read *pr, unsigned long vaddr,
> -			      unsigned long len, void *buf)
> +int pagemap_enqueue_iovec(struct page_read *pr, void *buf,
> +			      unsigned long len, struct list_head *to)
>  {
>  	struct page_read_iov *cur_async = NULL;
>  	struct iovec *iov;
> 
> -	if (!list_empty(&pr->async))
> -		cur_async = list_entry(pr->async.prev, struct page_read_iov, l);
> +	if (!list_empty(to))
> +		cur_async = list_entry(to->prev, struct page_read_iov, l);
> 
>  	/*
>  	 * We don't have any async requests or we have new read
> @@ -324,7 +325,7 @@ static int enqueue_async_page(struct page_read *pr, unsigned long vaddr,
>  	 * Start the new preadv request here.
>  	 */
>  	if (!cur_async || pr->pi_off != cur_async->end)
> -		return enqueue_async_iov(pr, len, buf);
> +		return enqueue_async_iov(pr, buf, len, to);
> 
>  	/*
>  	 * This read is pure continuation of the previous one. Let's
> @@ -339,7 +340,7 @@ static int enqueue_async_page(struct page_read *pr, unsigned long vaddr,
>  		unsigned int n_iovs = cur_async->nr + 1;
> 
>  		if (n_iovs >= IOV_MAX)
> -			return enqueue_async_iov(pr, len, buf);
> +			return enqueue_async_iov(pr, buf, len, to);
> 
>  		iov = xrealloc(cur_async->to, n_iovs * sizeof(*iov));
>  		if (!iov)
> @@ -372,7 +373,7 @@ static int maybe_read_page_local(struct page_read *pr, unsigned long vaddr,
>  	 * cached read.
>  	 */
>  	if ((flags & (PR_ASYNC|PR_ASAP)) == PR_ASYNC && !opts.remote)
> -		ret = enqueue_async_page(pr, vaddr, len, buf);
> +		ret = pagemap_enqueue_iovec(pr, buf, len, &pr->async);
>  	else {
>  		ret = read_local_page(pr, vaddr, len, buf);
>  		if (ret == 0 && pr->io_complete)
> -- 
> 2.5.5
> 
> _______________________________________________
> CRIU mailing list
> CRIU at openvz.org
> https://lists.openvz.org/mailman/listinfo/criu
>