From: Oscar Salvador <osalvador@suse.de>
To: david@redhat.com
Cc: mhocko@kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, vbabka@suse.cz, pasha.tatashin@soleen.com,
Oscar Salvador <osalvador@suse.de>
Subject: [RFC PATCH v3 4/4] mm,memory_hotplug: Add mhp_memmap_on_memory boot option
Date: Tue, 1 Dec 2020 12:51:58 +0100 [thread overview]
Message-ID: <20201201115158.22638-5-osalvador@suse.de> (raw)
In-Reply-To: <20201201115158.22638-1-osalvador@suse.de>
Self stored memmap leads to a sparse memory situation which is unsuitable
for workloads that requires large contiguous memory chunks.
Make this an opt-in which needs to be explicitly enabled.
Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
mm/memory_hotplug.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 4b4708512f82..858d6161e915 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -42,6 +42,8 @@
#include "internal.h"
#include "shuffle.h"
+static bool memmap_on_memory_enabled __read_mostly = false;
+
/*
* online_page_callback contains pointer to current page onlining function.
* Initially it is generic_online_page(). If it is required it could be
@@ -1034,7 +1036,7 @@ bool __weak arch_support_memmap_on_memory(void)
bool mhp_supports_memmap_on_memory(unsigned long size)
{
- if (!arch_support_memmap_on_memory() ||
+ if (!memmap_on_memory_enabled || !arch_support_memmap_on_memory() ||
!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) ||
size > memory_block_size_bytes())
return false;
@@ -1422,6 +1424,13 @@ static int __init cmdline_parse_movable_node(char *p)
}
early_param("movable_node", cmdline_parse_movable_node);
+static int __init cmdline_parse_memmap_on_memory(char *p)
+{
+ memmap_on_memory_enabled = true;
+ return 0;
+}
+early_param("mhp_memmap_on_memory", cmdline_parse_memmap_on_memory);
+
/* check which state of node_states will be changed when offline memory */
static void node_states_check_changes_offline(unsigned long nr_pages,
struct zone *zone, struct memory_notify *arg)
--
2.26.2
next prev parent reply other threads:[~2020-12-01 11:53 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-01 11:51 [RFC PATCH v3 0/4] Allocate memmap from hotadded memory (per device) Oscar Salvador
2020-12-01 11:51 ` [RFC PATCH v3 1/4] mm,memory_hotplug: Add mhp_supports_memmap_on_memory Oscar Salvador
2020-12-02 9:36 ` David Hildenbrand
2020-12-09 9:36 ` Oscar Salvador
2020-12-09 9:40 ` David Hildenbrand
2020-12-09 9:43 ` Oscar Salvador
2020-12-01 11:51 ` [RFC PATCH v3 2/4] mm,memory_hotplug: Allocate memmap from the added memory range Oscar Salvador
2020-12-02 10:05 ` David Hildenbrand
2020-12-09 10:32 ` Oscar Salvador
2020-12-09 11:51 ` Oscar Salvador
2020-12-01 11:51 ` [RFC PATCH v3 3/4] mm,memory_hotplug: Enable MHP_MEMMAP_ON_MEMORY when supported Oscar Salvador
2020-12-02 9:37 ` David Hildenbrand
2020-12-09 9:38 ` Oscar Salvador
2020-12-01 11:51 ` Oscar Salvador [this message]
2020-12-02 9:42 ` [RFC PATCH v3 4/4] mm,memory_hotplug: Add mhp_memmap_on_memory boot option David Hildenbrand
2020-12-09 10:02 ` Oscar Salvador
2020-12-09 10:04 ` David Hildenbrand
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