mm/page_alloc: remove track of active PCP lists range in bulk free

Patch series "Two minor cleanups for pcp list in page_alloc".

There are two minor cleanups for pcp list in page_alloc. More details
can be found in respective patches.

This patch (of 2):

After commit fd56eef258a17 ("mm/page_alloc: simplify how many pages are
selected per pcp list during bulk free"), we will drain all pages in
selected pcp list.  And we ensured passed count is < pcp->count.  Then,
the search will finish before wrap-around and track of active PCP lists
range intended for wrap-around case is no longer needed.

Link: https://lkml.kernel.org/r/20230809100754.3094517-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20230809100754.3094517-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 94f9e15..bc782bf 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1207,8 +1207,6 @@ static void free_pcppages_bulk(struct zone *zone, int count,
                                        int pindex)
 {
        unsigned long flags;
-       int min_pindex = 0;
-       int max_pindex = NR_PCP_LISTS - 1;
        unsigned int order;
        bool isolated_pageblocks;
        struct page *page;
@@ -1231,17 +1229,10 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 
                /* Remove pages from lists in a round-robin fashion. */
                do {
-                       if (++pindex > max_pindex)
-                               pindex = min_pindex;
+                       if (++pindex > NR_PCP_LISTS - 1)
+                               pindex = 0;
                        list = &pcp->lists[pindex];
-                       if (!list_empty(list))
-                               break;
-
-                       if (pindex == max_pindex)
-                               max_pindex--;
-                       if (pindex == min_pindex)
-                               min_pindex++;
-               } while (1);
+               } while (list_empty(list));
 
                order = pindex_to_order(pindex);
                nr_pages = 1 << order;