On Fri, Feb 17, 2017 at 10:05:44AM -0500, Zi Yan wrote:
> From: Zi Yan <ziy@xxxxxxxxxx>
>
> It supports copying a list of pages via multi-threaded process.
> It evenly distributes a list of pages to a group of threads and
> uses the same subroutine as copy_page_mthread()
The new function has many duplicate lines with copy_page_mthread(),
so please consider factoring out them into a common routine.
That makes your code more readable/maintainable.
Thanks,
Naoya Horiguchi
>
> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
> ---
> mm/copy_pages.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> mm/internal.h | 3 +++
> 2 files changed, 65 insertions(+)
>
> diff --git a/mm/copy_pages.c b/mm/copy_pages.c
> index c357e7b01042..516c0a1a57f3 100644
> --- a/mm/copy_pages.c
> +++ b/mm/copy_pages.c
> @@ -84,3 +84,65 @@ int copy_pages_mthread(struct page *to, struct page *from, int nr_pages)
> kfree(work_items);
> return 0;
> }
> +
> +int copy_page_lists_mthread(struct page **to, struct page **from, int nr_pages)
> +{
> + int err = 0;
> + unsigned int cthreads, node = page_to_nid(*to);
> + int i;
> + struct copy_info *work_items;
> + int nr_pages_per_page = hpage_nr_pages(*from);
> + const struct cpumask *cpumask = cpumask_of_node(node);
> + int cpu_id_list[32] = {0};
> + int cpu;
> +
> + cthreads = nr_copythreads;
> + cthreads = min_t(unsigned int, cthreads, cpumask_weight(cpumask));
> + cthreads = (cthreads / 2) * 2;
> + cthreads = min_t(unsigned int, nr_pages, cthreads);
> +
> + work_items = kzalloc(sizeof(struct copy_info)*nr_pages,
> + GFP_KERNEL);
> + if (!work_items)
> + return -ENOMEM;
> +
> + i = 0;
> + for_each_cpu(cpu, cpumask) {
> + if (i >= cthreads)
> + break;
> + cpu_id_list[i] = cpu;
> + ++i;
> + }
> +
> + for (i = 0; i < nr_pages; ++i) {
> + int thread_idx = i % cthreads;
> +
> + INIT_WORK((struct work_struct *)&work_items[i],
> + copythread);
> +
> + work_items[i].to = kmap(to[i]);
> + work_items[i].from = kmap(from[i]);
> + work_items[i].chunk_size = PAGE_SIZE * hpage_nr_pages(from[i]);
> +
> + BUG_ON(nr_pages_per_page != hpage_nr_pages(from[i]));
> + BUG_ON(nr_pages_per_page != hpage_nr_pages(to[i]));
> +
> +
> + queue_work_on(cpu_id_list[thread_idx],
> + system_highpri_wq,
> + (struct work_struct *)&work_items[i]);
> + }
> +
> + /* Wait until it finishes */
> + for (i = 0; i < cthreads; ++i)
> + flush_work((struct work_struct *) &work_items[i]);
> +
> + for (i = 0; i < nr_pages; ++i) {
> + kunmap(to[i]);
> + kunmap(from[i]);
> + }
> +
> + kfree(work_items);
> +
> + return err;
> +}
> diff --git a/mm/internal.h b/mm/internal.h
> index ccfc2a2969f4..175e08ed524a 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -498,4 +498,7 @@ extern const struct trace_print_flags pageflag_names[];
> extern const struct trace_print_flags vmaflag_names[];
> extern const struct trace_print_flags gfpflag_names[];
>
> +extern int copy_page_lists_mthread(struct page **to,
> + struct page **from, int nr_pages);
> +
> #endif /* __MM_INTERNAL_H */
> --
> 2.11.0
>
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