[PATCH 5/5] xfs: use xas_for_each_marked in xfs_reclaim_inodes_count

Christoph Hellwig
2024-08-21T06:39:18Z

xfs_reclaim_inodes_count iterates over all AGs to sum up the reclaimable
inodes counts. There is no point in grabbing a reference to the them or
unlock the RCU critical section for each iteration, so switch to the
more efficient xas_for_each_marked iterator.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_icache.c | 36 ++++++++----------------------------
fs/xfs/xfs_trace.h | 2 +-
2 files changed, 9 insertions(+), 29 deletions(-)

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 5bca845e702f1d..d36dbaba660013 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -300,32 +300,6 @@ xfs_perag_clear_inode_tag(
trace_xfs_perag_clear_inode_tag(pag, _RET_IP_);
}

-/*
- * Search from @first to find the next perag with the given tag set.
- */
-static struct xfs_perag *
-xfs_perag_get_next_tag(
- struct xfs_mount *mp,
- struct xfs_perag *pag,
- unsigned int tag)
-{
- unsigned long index = 0;
-
- if (pag) {
- index = pag->pag_agno + 1;
- xfs_perag_rele(pag);
- }
-
- rcu_read_lock();
- pag = xa_find(&mp->m_perags, &index, ULONG_MAX, ici_tag_to_mark(tag));
- if (pag) {
- trace_xfs_perag_get_next_tag(pag, _RET_IP_);
- atomic_inc(&pag->pag_ref);
- }
- rcu_read_unlock();
- return pag;
-}
-
/*
* Find the next AG after @pag, or the first AG if @pag is NULL.
*/
@@ -1080,11 +1054,17 @@ long
xfs_reclaim_inodes_count(
struct xfs_mount *mp)
{
- struct xfs_perag *pag = NULL;
+ XA_STATE (xas, &mp->m_perags, 0);
long reclaimable = 0;
+ struct xfs_perag *pag;

- while ((pag = xfs_perag_get_next_tag(mp, pag, XFS_ICI_RECLAIM_TAG)))
+ rcu_read_lock();
+ xas_for_each_marked(&xas, pag, ULONG_MAX, XFS_PERAG_RECLAIM_MARK) {
+ trace_xfs_reclaim_inodes_count(pag, _THIS_IP_);
reclaimable += pag->pag_ici_reclaimable;
+ }
+ rcu_read_unlock();
+
return reclaimable;
}

diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 002d012ebd83cb..d73c0a49d9dc29 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -210,7 +210,6 @@ DEFINE_EVENT(xfs_perag_class, name, \
TP_PROTO(struct xfs_perag *pag, unsigned long caller_ip), \
TP_ARGS(pag, caller_ip))
DEFINE_PERAG_REF_EVENT(xfs_perag_get);
-DEFINE_PERAG_REF_EVENT(xfs_perag_get_next_tag);
DEFINE_PERAG_REF_EVENT(xfs_perag_hold);
DEFINE_PERAG_REF_EVENT(xfs_perag_put);
DEFINE_PERAG_REF_EVENT(xfs_perag_grab);
@@ -218,6 +217,7 @@ DEFINE_PERAG_REF_EVENT(xfs_perag_grab_next_tag);
DEFINE_PERAG_REF_EVENT(xfs_perag_rele);
DEFINE_PERAG_REF_EVENT(xfs_perag_set_inode_tag);
DEFINE_PERAG_REF_EVENT(xfs_perag_clear_inode_tag);
+DEFINE_PERAG_REF_EVENT(xfs_reclaim_inodes_count);

TRACE_EVENT(xfs_inodegc_worker,
TP_PROTO(struct xfs_mount *mp, unsigned int shrinker_hits),
--
2.43.0