From: Baoquan He <bhe@redhat.com>
To: linux-mm@kvack.org
Cc: akpm@linux-foundation.org, rppt@kernel.org, mgorman@suse.de,
Baoquan He <bhe@redhat.com>
Subject: [PATCH 6/7] mm/page_alloc.c: don't show protection in zone's ->lowmem_reserve[] for empty zone
Date: Tue, 26 Mar 2024 14:11:32 +0800 [thread overview]
Message-ID: <20240326061134.1055295-7-bhe@redhat.com> (raw)
In-Reply-To: <20240326061134.1055295-1-bhe@redhat.com>
On one node, for lower zone's ->lowmem_reserve[], it will show how
much memory is reserved in this lower zone to avoid excessive page
allocation from the relevant higher zone's fallback allocation.
However, currently lower zone's lowmem_reserve[] element will be filled
even though the relevant higher zone is empty. That doesnt' make sense
and can cause confusion.
E.g on node 0 of one system as below, it has zone
DMA/DMA32/NORMAL/MOVABLE/DEVICE, among them zone MOVABLE/DEVICE are the
highest and both are empty. In zone DMA/DMA32's protection array, we can
see that it has value for zone MOVABLE and DEVICE.
Node 0, zone DMA
......
pages free 2816
boost 0
min 7
low 10
high 13
spanned 4095
present 3998
managed 3840
cma 0
protection: (0, 1582, 23716, 23716, 23716)
......
Node 0, zone DMA32
pages free 403269
boost 0
min 753
low 1158
high 1563
spanned 1044480
present 487039
managed 405070
cma 0
protection: (0, 0, 22134, 22134, 22134)
......
Node 0, zone Normal
pages free 5423879
boost 0
min 10539
low 16205
high 21871
spanned 5767168
present 5767168
managed 5666438
cma 0
protection: (0, 0, 0, 0, 0)
......
Node 0, zone Movable
pages free 0
boost 0
min 32
low 32
high 32
spanned 0
present 0
managed 0
cma 0
protection: (0, 0, 0, 0, 0)
Node 0, zone Device
pages free 0
boost 0
min 0
low 0
high 0
spanned 0
present 0
managed 0
cma 0
protection: (0, 0, 0, 0, 0)
Here, clear out the element value in lower zone's ->lowmem_reserve[] if the
relevant higher zone is empty.
And also replace space with tab in _deferred_grow_zone()
Signed-off-by: Baoquan He <bhe@redhat.com>
---
mm/page_alloc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fd2b49aed59e..ce1d12cf2ec7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -332,7 +332,7 @@ static inline bool deferred_pages_enabled(void)
static bool __ref
_deferred_grow_zone(struct zone *zone, unsigned int order)
{
- return deferred_grow_zone(zone, order);
+ return deferred_grow_zone(zone, order);
}
#else
static inline bool deferred_pages_enabled(void)
@@ -5806,10 +5806,11 @@ static void setup_per_zone_lowmem_reserve(void)
for (j = i + 1; j < MAX_NR_ZONES; j++) {
struct zone *upper_zone = &pgdat->node_zones[j];
+ bool empty = !zone_managed_pages(upper_zone);
managed_pages += zone_managed_pages(upper_zone);
- if (clear)
+ if (clear || empty)
zone->lowmem_reserve[j] = 0;
else
zone->lowmem_reserve[j] = managed_pages / ratio;
--
2.41.0
next prev parent reply other threads:[~2024-03-26 6:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-26 6:11 [PATCH 0/7] mm/init: minor clean up and improvement Baoquan He
2024-03-26 6:11 ` [PATCH 1/7] mm: move array mem_section init code out of memory_present() Baoquan He
2024-04-02 8:19 ` Mike Rapoport
2024-04-04 1:38 ` Baoquan He
2024-03-26 6:11 ` [PATCH 2/7] mm/init: remove the unnecessary special treatment for memory-less node Baoquan He
2024-04-02 8:32 ` Mike Rapoport
2024-04-04 3:23 ` Baoquan He
2024-04-09 15:40 ` Mike Rapoport
2024-04-10 3:38 ` Baoquan He
2024-04-10 3:35 ` [PATCH v2 " Baoquan He
2024-03-26 6:11 ` [PATCH 3/7] mm: make __absent_pages_in_range() as static Baoquan He
2024-04-02 8:29 ` Mike Rapoport
2024-03-26 6:11 ` [PATCH 4/7] mm/page_alloc.c: remove unneeded codes in !NUMA version of build_zonelists() Baoquan He
2024-03-27 1:53 ` kernel test robot
2024-03-27 10:58 ` Baoquan He
2024-03-27 12:06 ` [PATCH v2 " Baoquan He
2024-03-26 6:11 ` [PATCH 5/7] mm/mm_init.c: remove the outdated code comment above deferred_grow_zone() Baoquan He
2024-04-02 8:30 ` Mike Rapoport
2024-03-26 6:11 ` Baoquan He [this message]
2024-03-26 6:11 ` [PATCH 7/7] mm/page_alloc.c: change the array-length to MIGRATE_PCPTYPES Baoquan He
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