mm/compaction: call list_is_{first}/{last} more intuitively in move_freelist_{head...

We use move_freelist_head after list_for_each_entry_reverse to skip recent
pages.  And there is no need to do actual move if all freepages are
searched in list_for_each_entry_reverse, e.g.  freepage point to first
page in freelist.  It's more intuitively to call list_is_first with list
entry as the first argument and list head as the second argument to check
if list entry is the first list entry instead of call list_is_last with
list entry and list head passed in reverse.

Similarly, call list_is_last in move_freelist_tail is more intuitively.

Link: https://lkml.kernel.org/r/20230901155141.249860-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/compaction.c b/mm/compaction.c
index e3ee1bc1c0adb75cf33bd8ff336941ab56b26428..a40550a33aee691b08bbebec36336b30abcd65d6 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1395,7 +1395,7 @@ move_freelist_head(struct list_head *freelist, struct page *freepage)
 {
        LIST_HEAD(sublist);
 
-       if (!list_is_last(freelist, &freepage->buddy_list)) {
+       if (!list_is_first(&freepage->buddy_list, freelist)) {
                list_cut_before(&sublist, freelist, &freepage->buddy_list);
                list_splice_tail(&sublist, freelist);
        }
@@ -1412,7 +1412,7 @@ move_freelist_tail(struct list_head *freelist, struct page *freepage)
 {
        LIST_HEAD(sublist);
 
-       if (!list_is_first(freelist, &freepage->buddy_list)) {
+       if (!list_is_last(&freepage->buddy_list, freelist)) {
                list_cut_position(&sublist, freelist, &freepage->buddy_list);
                list_splice_tail(&sublist, freelist);
        }