[PATCH 38/45] xfs: convert CIL busy extents to per-cpu

Dave Chinner
2021-03-05T05:12:53Z

From: Dave Chinner <dchinner@redhat.com>

To get them out from under the CIL lock.

This is an unordered list, so we can simply punt it to per-cpu lists
during transaction commits and reaggregate it back into a single
list during the CIL push work.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_log_cil.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index a2f93bd7644b..7428b98c8279 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -501,6 +501,9 @@ xlog_cil_insert_items(
atomic_add(cilpcp->space_used, &ctx->space_used);
cilpcp->space_used = 0;
}
+ /* attach the transaction to the CIL if it has any busy extents */
+ if (!list_empty(&tp->t_busy))
+ list_splice_init(&tp->t_busy, &cilpcp->busy_extents);
put_cpu_ptr(cilpcp);

/*
@@ -540,9 +543,6 @@ xlog_cil_insert_items(
list_move_tail(&lip->li_cil, &cil->xc_cil);
}

- /* attach the transaction to the CIL if it has any busy extents */
- if (!list_empty(&tp->t_busy))
- list_splice_init(&tp->t_busy, &ctx->busy_extents);
spin_unlock(&cil->xc_cil_lock);

if (tp->t_ticket->t_curr_res < 0)
@@ -802,7 +802,10 @@ xlog_cil_push_work(
ctx->ticket->t_curr_res += cilpcp->space_reserved;
cilpcp->space_used = 0;
cilpcp->space_reserved = 0;
-
+ if (!list_empty(&cilpcp->busy_extents)) {
+ list_splice_init(&cilpcp->busy_extents,
+ &ctx->busy_extents);
+ }
}

spin_lock(&cil->xc_push_lock);
@@ -1459,17 +1462,24 @@ static void __percpu *
xlog_cil_pcp_alloc(
struct xfs_cil *cil)
{
+ void __percpu *pcptr;
struct xlog_cil_pcp *cilpcp;
+ int cpu;

- cilpcp = alloc_percpu(struct xlog_cil_pcp);
- if (!cilpcp)
+ pcptr = alloc_percpu(struct xlog_cil_pcp);
+ if (!pcptr)
return NULL;

+ for_each_possible_cpu(cpu) {
+ cilpcp = per_cpu_ptr(pcptr, cpu);
+ INIT_LIST_HEAD(&cilpcp->busy_extents);
+ }
+
if (xlog_cil_pcp_hpadd(cil) < 0) {
- free_percpu(cilpcp);
+ free_percpu(pcptr);
return NULL;
}
- return cilpcp;
+ return pcptr;
}

static void
--
2.28.0