Re: [PATCH 2/3] xfs: convert perag lookup to xarray

Matthew Wilcox
2024-08-12T14:39:38Z

On Mon, Aug 12, 2024 at 08:31:01AM +0200, Christoph Hellwig wrote:
> @@ -1020,14 +1016,16 @@ xfs_reclaim_inodes_count(
> struct xfs_mount *mp)
> {
> struct xfs_perag *pag;
> - xfs_agnumber_t ag = 0;
> + unsigned long index = 0;
> long reclaimable = 0;
>
> - while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
> - ag = pag->pag_agno + 1;
> + rcu_read_lock();
> + xa_for_each_marked(&mp->m_perags, index, pag, XFS_ICI_RECLAIM_TAG) {
> + trace_xfs_reclaim_inodes_count(pag, _THIS_IP_);
> reclaimable += pag->pag_ici_reclaimable;
> - xfs_perag_put(pag);
> }
> + rcu_read_unlock();

Would you rather use xas_for_each_marked() here? O(n) rather than
O(n.log(n)).

Other than that, looks like a straightforward and correct conversion.