+ mm-compaction-call-list_is_first-last-more-intuitively-in-move_freelist_head-tail.patch added to mm-unstable branch

+ mm-compaction-call-list_is_first-last-more-intuitively-in-move_freelist_head-tail.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/compaction: call list_is_{first}/{last} more intuitively in move_freelist_{head}/{tail}
has been added to the -mm mm-unstable branch.  Its filename is
     mm-compaction-call-list_is_first-last-more-intuitively-in-move_freelist_head-tail.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-compaction-call-list_is_first-last-more-intuitively-in-move_freelist_head-tail.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@huaweicloud.com>
Subject: mm/compaction: call list_is_{first}/{last} more intuitively in move_freelist_{head}/{tail}
Date: Fri, 1 Sep 2023 23:51:37 +0800

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>
---

 mm/compaction.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/compaction.c~mm-compaction-call-list_is_first-last-more-intuitively-in-move_freelist_head-tail
+++ a/mm/compaction.c
@@ -1395,7 +1395,7 @@ move_freelist_head(struct list_head *fre
 {
 	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 *fre
 {
 	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);
 	}
_

Patches currently in -mm which might be from shikemeng@huaweicloud.com are

mm-compaction-use-correct-list-in-move_freelist_head-tail.patch
mm-compaction-call-list_is_first-last-more-intuitively-in-move_freelist_head-tail.patch
mm-compaction-correctly-return-failure-with-bogus-compound_order-in-strict-mode.patch
mm-compaction-remove-repeat-compact_blockskip_flush-check-in-reset_isolation_suitable.patch
mm-compaction-improve-comment-of-is_via_compact_memory.patch
mm-compaction-factor-out-code-to-test-if-we-should-run-compaction-for-target-order.patch