The patch titled
Subject: mm, swap: remove setting SWAP_MAP_BAD for discard cluster
has been added to the -mm mm-unstable branch. Its filename is
mm-swap-remove-setting-swap_map_bad-for-discard-cluster.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-remove-setting-swap_map_bad-for-discard-cluster.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Subject: mm, swap: remove setting SWAP_MAP_BAD for discard cluster
Date: Sun, 23 Feb 2025 00:08:48 +0800
Before alloc from a cluster, we will aqcuire cluster's lock and make sure
it is usable by cluster_is_usable(), so there is no need to set
SWAP_MAP_BAD for cluster to be discarded.
Link: https://lkml.kernel.org/r/20250222160850.505274-5-shikemeng@xxxxxxxxxxxxxxx
Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Cc: Kairui Song <ryncsn@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 11 -----------
1 file changed, 11 deletions(-)
--- a/mm/swapfile.c~mm-swap-remove-setting-swap_map_bad-for-discard-cluster
+++ a/mm/swapfile.c
@@ -479,15 +479,6 @@ static void move_cluster(struct swap_inf
static void swap_cluster_schedule_discard(struct swap_info_struct *si,
struct swap_cluster_info *ci)
{
- unsigned int idx = cluster_index(si, ci);
- /*
- * If scan_swap_map_slots() can't find a free cluster, it will check
- * si->swap_map directly. To make sure the discarding cluster isn't
- * taken by scan_swap_map_slots(), mark the swap entries bad (occupied).
- * It will be cleared after discard
- */
- memset(si->swap_map + idx * SWAPFILE_CLUSTER,
- SWAP_MAP_BAD, SWAPFILE_CLUSTER);
VM_BUG_ON(ci->flags == CLUSTER_FLAG_FREE);
move_cluster(si, ci, &si->discard_clusters, CLUSTER_FLAG_DISCARD);
schedule_work(&si->discard_work);
@@ -571,8 +562,6 @@ static bool swap_do_scheduled_discard(st
* return the cluster to allocation list.
*/
ci->flags = CLUSTER_FLAG_NONE;
- memset(si->swap_map + idx * SWAPFILE_CLUSTER,
- 0, SWAPFILE_CLUSTER);
__free_cluster(si, ci);
spin_unlock(&ci->lock);
ret = true;
_
Patches currently in -mm which might be from shikemeng@xxxxxxxxxxxxxxx are
mm-swap-avoid-losting-cluster-in-swap_reclaim_full_clusters.patch
mm-swap-use-correct-step-in-loop-to-wait-all-clusters-in-wait_for_allocation.patch
mm-swap-avoid-bug_on-in-relocate_cluster.patch
mm-swap-remove-setting-swap_map_bad-for-discard-cluster.patch
mm-swap-correct-comment-in-swap_usage_sub.patch
mm-swap-remove-stale-comment-of-swap_reclaim_full_clusters.patch
