Re: [PATCH 2/2] repair/prefetch.c: Create one workqueue with multiple workers

Darrick J. Wong
2025-11-04T16:55:35Z

On Tue, Nov 04, 2025 at 02:44:37PM +0530, Chandan Babu R wrote:
> When xfs_repair is executed with a non-zero value for ag_stride,
> do_inode_prefetch() create multiple workqueues with each of them having just
> one worker thread.
>
> Since commit 12838bda12e669 ("libfrog: fix overly sleep workqueues"), a
> workqueue can process multiple work items concurrently. Hence, this commit
> replaces the above logic with just one workqueue having multiple workers.
>
> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

Yeah, this also makes sense to me. I wonder if this odd code was some
sort of workaround for the pre-12838bd workqueue behavior?

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
> repair/prefetch.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/repair/prefetch.c b/repair/prefetch.c
> index 5ecf19ae9..8cd3416fa 100644
> --- a/repair/prefetch.c
> +++ b/repair/prefetch.c
> @@ -1024,7 +1024,6 @@ do_inode_prefetch(
> {
> int i;
> struct workqueue queue;
> - struct workqueue *queues;
> int queues_started = 0;
>
> /*
> @@ -1056,7 +1055,7 @@ do_inode_prefetch(
> /*
> * create one worker thread for each segment of the volume
> */
> - queues = malloc(thread_count * sizeof(struct workqueue));
> + create_work_queue(&queue, mp, thread_count);
> for (i = 0; i < thread_count; i++) {
> struct pf_work_args *wargs;
>
> @@ -1067,8 +1066,7 @@ do_inode_prefetch(
> wargs->dirs_only = dirs_only;
> wargs->func = func;
>
> - create_work_queue(&queues[i], mp, 1);
> - queue_work(&queues[i], prefetch_ag_range_work, 0, wargs);
> + queue_work(&queue, prefetch_ag_range_work, 0, wargs);
> queues_started++;
>
> if (wargs->end_ag >= mp->m_sb.sb_agcount)
> @@ -1078,9 +1076,7 @@ do_inode_prefetch(
> /*
> * wait for workers to complete
> */
> - for (i = 0; i < queues_started; i++)
> - destroy_work_queue(&queues[i]);
> - free(queues);
> + destroy_work_queue(&queue);
> }
>
> void
> --
> 2.45.2
>
>