The current calculation of min_free_kbytes only uses ZONE_DMA and
ZONE_NORMAL pages,but the ZONE_MOVABLE zone->_watermark[WMARK_MIN] will
also divide part of min_free_kbytes.This will cause the min watermark of
ZONE_NORMAL to be too small in the presence of ZONE_MOVEABLE.
__GFP_HIGH and PF_MEMALLOC allocations usually don't need movable zone
pages, so just like ZONE_HIGHMEM, cap pages_min to a small value in
__setup_per_zone_wmarks().
On my testing machine with 16GB of memory (transparent hugepage is turned
off by default, and movablecore=12G is configured) The following is a
comparative test data of watermark_min
no patch add patch
ZONE_DMA 1 8
ZONE_DMA32 151 709
ZONE_NORMAL 233 1113
ZONE_MOVABLE 1434 128
min_free_kbytes 7288 7326
Link: https://lkml.kernel.org/r/20230625031656.23941-1-liuq131@chinatelecom.cn
Signed-off-by: liuq <liuq131@chinatelecom.cn>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
struct zone *zone;
unsigned long flags;
struct zone *zone;
unsigned long flags;
- /* Calculate total number of !ZONE_HIGHMEM pages */
+ /* Calculate total number of !ZONE_HIGHMEM and !ZONE_MOVABLE pages */
+ if (!is_highmem(zone) && zone_idx(zone) != ZONE_MOVABLE)
lowmem_pages += zone_managed_pages(zone);
}
lowmem_pages += zone_managed_pages(zone);
}
spin_lock_irqsave(&zone->lock, flags);
tmp = (u64)pages_min * zone_managed_pages(zone);
do_div(tmp, lowmem_pages);
spin_lock_irqsave(&zone->lock, flags);
tmp = (u64)pages_min * zone_managed_pages(zone);
do_div(tmp, lowmem_pages);
- if (is_highmem(zone)) {
+ if (is_highmem(zone) || zone_idx(zone) == ZONE_MOVABLE) {
/*
* __GFP_HIGH and PF_MEMALLOC allocations usually don't
/*
* __GFP_HIGH and PF_MEMALLOC allocations usually don't
- * need highmem pages, so cap pages_min to a small
- * value here.
+ * need highmem and movable zones pages, so cap pages_min
+ * to a small value here.
*
* The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
* deltas control async page reclaim, and so should
*
* The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
* deltas control async page reclaim, and so should
- * not be capped for highmem.
+ * not be capped for highmem and movable zones.
*/
unsigned long min_pages;
*/
unsigned long min_pages;