Commit 4b9ae842 authored by Miaohe Lin's avatar Miaohe Lin Committed by Andrew Morton
Browse files

mm/swap: add helper swap_offset_available() 

Add helper swap_offset_available() to remove some duplicated codes.  Minor
readability improvement.

[akpm@linux-foundation.org: s/swap_offset_available/swap_offset_available_and_locked/, per Neil]
Link: https://lkml.kernel.org/r/20220509131416.17553-12-linmiaohe@huawei.com


Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent eacde327

mm/swapfile.c

+18 −16
Original line number Diff line number Diff line
@@ -775,6 +775,22 @@ static void set_cluster_next(struct swap_info_struct *si, unsigned long next) 
	this_cpu_write(*si->cluster_next_cpu, next);

}



static bool swap_offset_available_and_locked(struct swap_info_struct *si,

					     unsigned long offset)

{

	if (data_race(!si->swap_map[offset])) {

		spin_lock(&si->lock);

		return true;

	}



	if (vm_swap_full() && READ_ONCE(si->swap_map[offset]) == SWAP_HAS_CACHE) {

		spin_lock(&si->lock);

		return true;

	}



	return false;

}



static int scan_swap_map_slots(struct swap_info_struct *si,

			       unsigned char usage, int nr,

			       swp_entry_t slots[])
@@ -952,15 +968,8 @@ static int scan_swap_map_slots(struct swap_info_struct *si, 
scan:

	spin_unlock(&si->lock);

	while (++offset <= READ_ONCE(si->highest_bit)) {

		if (data_race(!si->swap_map[offset])) {

			spin_lock(&si->lock);

		if (swap_offset_available_and_locked(si, offset))

			goto checks;

		}

		if (vm_swap_full() &&

		    READ_ONCE(si->swap_map[offset]) == SWAP_HAS_CACHE) {

			spin_lock(&si->lock);

			goto checks;

		}

		if (unlikely(--latency_ration < 0)) {

			cond_resched();

			latency_ration = LATENCY_LIMIT;
@@ -969,15 +978,8 @@ static int scan_swap_map_slots(struct swap_info_struct *si, 
	}

	offset = si->lowest_bit;

	while (offset < scan_base) {

		if (data_race(!si->swap_map[offset])) {

			spin_lock(&si->lock);

			goto checks;

		}

		if (vm_swap_full() &&

		    READ_ONCE(si->swap_map[offset]) == SWAP_HAS_CACHE) {

			spin_lock(&si->lock);

		if (swap_offset_available_and_locked(si, offset))

			goto checks;

		}

		if (unlikely(--latency_ration < 0)) {

			cond_resched();

			latency_ration = LATENCY_LIMIT;