Re: [PATCH 14/35] autonuma: knuma_migrated per NUMA node queues

Andrea Arcangeli
2012-05-30T18:21:30Z

On Wed, May 30, 2012 at 02:14:38AM +0200, Andrea Arcangeli wrote:
> I fully agree, I prefer to fix it and I was fully aware about

I did this yesterday, this is saving a couple of pages on my numa
system with node shift = 9. However I'm not sure anymore if it's
really worth it... but since I did it I may as well keep it.

==
From: Andrea Arcangeli <aarcange@redhat.com>
Subject: [PATCH] autonuma: autonuma_migrate_head[0] dynamic size

Reduce the autonuma_migrate_head array entries from MAX_NUMNODES to
num_possible_nodes() or zero if autonuma_impossible() is true.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---
arch/x86/mm/numa.c | 6 ++++--
arch/x86/mm/numa_32.c | 3 ++-
include/linux/memory_hotplug.h | 3 ++-
include/linux/mmzone.h | 8 +++++++-
include/linux/page_autonuma.h | 10 ++++++++--
mm/memory_hotplug.c | 2 +-
mm/page_autonuma.c | 5 +++--
7 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 2d125be..a4a9e92 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -11,6 +11,7 @@
#include <linux/nodemask.h>
#include <linux/sched.h>
#include <linux/topology.h>
+#include <linux/page_autonuma.h>

#include <asm/e820.h>
#include <asm/proto.h>
@@ -192,7 +193,8 @@ int __init numa_add_memblk(int nid, u64 start, u64 end)
/* Initialize NODE_DATA for a node on the local memory */
static void __init setup_node_data(int nid, u64 start, u64 end)
{
- const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
+ const size_t nd_size = roundup(autonuma_pglist_data_size(),
+ PAGE_SIZE);
bool remapped = false;
u64 nd_pa;
void *nd;
@@ -239,7 +241,7 @@ static void __init setup_node_data(int nid, u64 start, u64 end)
printk(KERN_INFO " NODE_DATA(%d) on node %d\n", nid, tnid);

node_data[nid] = nd;
- memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
+ memset(NODE_DATA(nid), 0, autonuma_pglist_data_size());
NODE_DATA(nid)->node_id = nid;
NODE_DATA(nid)->node_start_pfn = start >> PAGE_SHIFT;
NODE_DATA(nid)->node_spanned_pages = (end - start) >> PAGE_SHIFT;
diff --git a/arch/x86/mm/numa_32.c b/arch/x86/mm/numa_32.c
index 534255a..d32d6cc 100644
--- a/arch/x86/mm/numa_32.c
+++ b/arch/x86/mm/numa_32.c
@@ -25,6 +25,7 @@
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/module.h>
+#include <linux/page_autonuma.h>

#include "numa_internal.h"

@@ -194,7 +195,7 @@ void __init init_alloc_remap(int nid, u64 start, u64 end)

/* calculate the necessary space aligned to large page size */
size = node_memmap_size_bytes(nid, start_pfn, end_pfn);
- size += ALIGN(sizeof(pg_data_t), PAGE_SIZE);
+ size += ALIGN(autonuma_pglist_data_size(), PAGE_SIZE);
size = ALIGN(size, LARGE_PAGE_BYTES);

/* allocate node memory and the lowmem remap area */
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 910550f..76b1840 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -5,6 +5,7 @@
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <linux/bug.h>
+#include <linux/page_autonuma.h>

struct page;
struct zone;
@@ -130,7 +131,7 @@ extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
*/
#define generic_alloc_nodedata(nid) \
({ \
- kzalloc(sizeof(pg_data_t), GFP_KERNEL); \
+ kzalloc(autonuma_pglist_data_size(), GFP_KERNEL); \
})
/*
* This definition is just for error path in node hotadd.
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index e66da74..ed5b0c0 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -701,10 +701,16 @@ typedef struct pglist_data {
#if !defined(CONFIG_SPARSEMEM)
struct page_autonuma *node_page_autonuma;
#endif
- struct list_head autonuma_migrate_head[MAX_NUMNODES];
unsigned long autonuma_nr_migrate_pages;
wait_queue_head_t autonuma_knuma_migrated_wait;
spinlock_t autonuma_lock;
+ /*
+ * Archs supporting AutoNUMA should allocate the pgdat with
+ * size autonuma_pglist_data_size() after including
+ * <linux/page_autonuma.h> and the below field must remain the
+ * last one of this structure.
+ */
+ struct list_head autonuma_migrate_head[0];
#endif
} pg_data_t;

diff --git a/include/linux/page_autonuma.h b/include/linux/page_autonuma.h
index 05d2862..1d02643 100644
--- a/include/linux/page_autonuma.h
+++ b/include/linux/page_autonuma.h
@@ -10,6 +10,7 @@ static inline void __init page_autonuma_init_flatmem(void) {}
#ifdef CONFIG_AUTONUMA

#include <linux/autonuma_flags.h>
+#include <linux/autonuma_types.h>

extern void __meminit page_autonuma_map_init(struct page *page,
struct page_autonuma *page_autonuma,
@@ -29,11 +30,10 @@ extern void __meminit pgdat_autonuma_init(struct pglist_data *);
struct page_autonuma;
#define PAGE_AUTONUMA_SIZE 0
#define SECTION_PAGE_AUTONUMA_SIZE 0
+#endif

#define autonuma_impossible() true

-#endif
-
static inline void pgdat_autonuma_init(struct pglist_data *pgdat) {}

#endif /* CONFIG_AUTONUMA */
@@ -50,4 +50,10 @@ extern void __init sparse_early_page_autonuma_alloc_node(struct page_autonuma **
int nodeid);
#endif

+/* inline won't work here */
+#define autonuma_pglist_data_size() (sizeof(struct pglist_data) + \
+ (autonuma_impossible() ? 0 : \
+ sizeof(struct list_head) * \
+ num_possible_nodes()))
+
#endif /* _LINUX_PAGE_AUTONUMA_H */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0d7e3ec..604995b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -164,7 +164,7 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat)
struct page *page;
struct zone *zone;

- nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
+ nr_pages = PAGE_ALIGN(autonuma_pglist_data_size()) >> PAGE_SHIFT;
page = virt_to_page(pgdat);

for (i = 0; i < nr_pages; i++, page++)
diff --git a/mm/page_autonuma.c b/mm/page_autonuma.c
index 131b5c9..c5c340b 100644
--- a/mm/page_autonuma.c
+++ b/mm/page_autonuma.c
@@ -23,8 +23,9 @@ static void __meminit __pgdat_autonuma_init(struct pglist_data *pgdat)
spin_lock_init(&pgdat->autonuma_lock);
init_waitqueue_head(&pgdat->autonuma_knuma_migrated_wait);
pgdat->autonuma_nr_migrate_pages = 0;
- for_each_node(node_iter)
- INIT_LIST_HEAD(&pgdat->autonuma_migrate_head[node_iter]);
+ if (!autonuma_impossible())
+ for_each_node(node_iter)
+ INIT_LIST_HEAD(&pgdat->autonuma_migrate_head[node_iter]);
}

#if !defined(CONFIG_SPARSEMEM)