Commit 43e9bbc3 authored by Kemeng Shi's avatar Kemeng Shi Committed by Andrew Morton
Browse files

mm, swap: remove setting SWAP_MAP_BAD for discard cluster 

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@huaweicloud.com


Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: default avatarKairui Song <kasong@tencent.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1ddae9d6

mm/swapfile.c

+0 −11
Original line number Diff line number Diff line
@@ -479,15 +479,6 @@ static void move_cluster(struct swap_info_struct *si, 
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(struct swap_info_struct *si) 
		 * 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;