[PATCH] replace various uses of num_physpages by totalram_pages

From: Jan Beulich
Date: Tue Jun 30 2009 - 07:08:47 EST

Sizing of memory allocations shouldn't depend on the number of physical
pages found in a system, as that generally include (perhaps a huge
amount of) non-RAM pages. The amount of what actually is usable as
storage should instead be used as a basis here.

In line with that, the memory hotplug code should update num_physpages
in a way that it retains its original (post-boot) meaning; in
particular, decreasing the value should at best be done with great care
- this patch doesn't try to ever decrease this value at all as it
doesn't really seem meaningful to do so.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

---
drivers/char/agp/backend.c | 4 ++--
drivers/parisc/ccio-dma.c | 4 ++--
drivers/parisc/sba_iommu.c | 4 ++--
drivers/xen/balloon.c | 4 ----
fs/ntfs/malloc.h | 2 +-
include/linux/mm.h | 1 +
init/main.c | 4 ++--
mm/memory_hotplug.c | 6 ++++--
mm/slab.c | 2 +-
mm/swap.c | 2 +-
mm/vmalloc.c | 4 ++--
net/core/sock.c | 4 ++--
net/dccp/proto.c | 6 +++---
net/decnet/dn_route.c | 2 +-
net/ipv4/route.c | 2 +-
net/ipv4/tcp.c | 4 ++--
net/netfilter/nf_conntrack_core.c | 4 ++--
net/netfilter/x_tables.c | 2 +-
net/netfilter/xt_hashlimit.c | 8 ++++----
net/netlink/af_netlink.c | 6 +++---
net/sctp/protocol.c | 6 +++---
21 files changed, 40 insertions(+), 41 deletions(-)

--- linux-2.6.31-rc1/drivers/char/agp/backend.c 2009-06-26 17:49:43.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/drivers/char/agp/backend.c 2009-06-24 16:09:34.000000000 +0200
@@ -114,9 +114,9 @@ static int agp_find_max(void)
long memory, index, result;

#if PAGE_SHIFT < 20
- memory = num_physpages >> (20 - PAGE_SHIFT);
+ memory = totalram_pages >> (20 - PAGE_SHIFT);
#else
- memory = num_physpages << (PAGE_SHIFT - 20);
+ memory = totalram_pages << (PAGE_SHIFT - 20);
#endif
index = 1;

--- linux-2.6.31-rc1/drivers/parisc/ccio-dma.c 2009-06-10 05:05:27.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/drivers/parisc/ccio-dma.c 2009-06-24 16:10:47.000000000 +0200
@@ -1267,7 +1267,7 @@ ccio_ioc_init(struct ioc *ioc)
** Hot-Plug/Removal of PCI cards. (aka PCI OLARD).
*/

- iova_space_size = (u32) (num_physpages / count_parisc_driver(&ccio_driver));
+ iova_space_size = (u32) (totalram_pages / count_parisc_driver(&ccio_driver));

/* limit IOVA space size to 1MB-1GB */

@@ -1306,7 +1306,7 @@ ccio_ioc_init(struct ioc *ioc)

DBG_INIT("%s() hpa 0x%p mem %luMB IOV %dMB (%d bits)\n",
__func__, ioc->ioc_regs,
- (unsigned long) num_physpages >> (20 - PAGE_SHIFT),
+ (unsigned long) totalram_pages >> (20 - PAGE_SHIFT),
iova_space_size>>20,
iov_order + PAGE_SHIFT);

--- linux-2.6.31-rc1/drivers/parisc/sba_iommu.c 2009-06-26 17:49:47.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/drivers/parisc/sba_iommu.c 2009-06-24 16:10:58.000000000 +0200
@@ -1390,7 +1390,7 @@ sba_ioc_init(struct parisc_device *sba,
** for DMA hints - ergo only 30 bits max.
*/

- iova_space_size = (u32) (num_physpages/global_ioc_cnt);
+ iova_space_size = (u32) (totalram_pages/global_ioc_cnt);

/* limit IOVA space size to 1MB-1GB */
if (iova_space_size < (1 << (20 - PAGE_SHIFT))) {
@@ -1415,7 +1415,7 @@ sba_ioc_init(struct parisc_device *sba,
DBG_INIT("%s() hpa 0x%lx mem %ldMB IOV %dMB (%d bits)\n",
__func__,
ioc->ioc_hpa,
- (unsigned long) num_physpages >> (20 - PAGE_SHIFT),
+ (unsigned long) totalram_pages >> (20 - PAGE_SHIFT),
iova_space_size>>20,
iov_order + PAGE_SHIFT);

--- linux-2.6.31-rc1/drivers/xen/balloon.c 2009-06-10 05:05:27.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/drivers/xen/balloon.c 2009-06-24 16:02:01.000000000 +0200
@@ -96,11 +96,7 @@ static struct balloon_stats balloon_stat
/* We increase/decrease in batches which fit in a page */
static unsigned long frame_list[PAGE_SIZE / sizeof(unsigned long)];

-/* VM /proc information for memory */
-extern unsigned long totalram_pages;
-
#ifdef CONFIG_HIGHMEM
-extern unsigned long totalhigh_pages;
#define inc_totalhigh_pages() (totalhigh_pages++)
#define dec_totalhigh_pages() (totalhigh_pages--)
#else
--- linux-2.6.31-rc1/fs/ntfs/malloc.h 2008-04-17 04:49:44.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/fs/ntfs/malloc.h 2009-06-24 16:11:49.000000000 +0200
@@ -47,7 +47,7 @@ static inline void *__ntfs_malloc(unsign
return kmalloc(PAGE_SIZE, gfp_mask & ~__GFP_HIGHMEM);
/* return (void *)__get_free_page(gfp_mask); */
}
- if (likely(size >> PAGE_SHIFT < num_physpages))
+ if (likely((size >> PAGE_SHIFT) < totalram_pages))
return __vmalloc(size, gfp_mask, PAGE_KERNEL);
return NULL;
}
--- linux-2.6.31-rc1/include/linux/mm.h 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/include/linux/mm.h 2009-06-24 16:00:50.000000000 +0200
@@ -25,6 +25,7 @@ extern unsigned long max_mapnr;
#endif

extern unsigned long num_physpages;
+extern unsigned long totalram_pages;
extern void * high_memory;
extern int page_cluster;

--- linux-2.6.31-rc1/init/main.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/init/main.c 2009-06-24 16:12:30.000000000 +0200
@@ -691,12 +691,12 @@ asmlinkage void __init start_kernel(void
#endif
thread_info_cache_init();
cred_init();
- fork_init(num_physpages);
+ fork_init(totalram_pages);
proc_caches_init();
buffer_init();
key_init();
security_init();
- vfs_caches_init(num_physpages);
+ vfs_caches_init(totalram_pages);
radix_tree_init();
signals_init();
/* rootfs populating might need page-writeback */
--- linux-2.6.31-rc1/mm/memory_hotplug.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/mm/memory_hotplug.c 2009-06-24 16:04:44.000000000 +0200
@@ -339,8 +339,11 @@ EXPORT_SYMBOL_GPL(__remove_pages);

void online_page(struct page *page)
{
+ unsigned long pfn = page_to_pfn(page);
+
totalram_pages++;
- num_physpages++;
+ if (pfn >= num_physpages)
+ num_physpages = pfn + 1;

#ifdef CONFIG_HIGHMEM
if (PageHighMem(page))
@@ -831,7 +834,6 @@ repeat:
zone->present_pages -= offlined_pages;
zone->zone_pgdat->node_present_pages -= offlined_pages;
totalram_pages -= offlined_pages;
- num_physpages -= offlined_pages;

setup_per_zone_wmarks();
calculate_zone_inactive_ratio(zone);
--- linux-2.6.31-rc1/mm/slab.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/mm/slab.c 2009-06-24 16:06:21.000000000 +0200
@@ -1384,7 +1384,7 @@ void __init kmem_cache_init(void)
* Fragmentation resistance on low memory - only use bigger
* page orders on machines with more than 32MB of memory.
*/
- if (num_physpages > (32 << 20) >> PAGE_SHIFT)
+ if (totalram_pages > (32 << 20) >> PAGE_SHIFT)
slab_break_gfp_order = BREAK_GFP_ORDER_HI;

/* Bootstrap is tricky, because several objects are allocated
--- linux-2.6.31-rc1/mm/swap.c 2009-06-10 05:05:27.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/mm/swap.c 2009-06-24 16:06:40.000000000 +0200
@@ -496,7 +496,7 @@ EXPORT_SYMBOL(pagevec_lookup_tag);
*/
void __init swap_setup(void)
{
- unsigned long megs = num_physpages >> (20 - PAGE_SHIFT);
+ unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT);

#ifdef CONFIG_SWAP
bdi_init(swapper_space.backing_dev_info);
--- linux-2.6.31-rc1/mm/vmalloc.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/mm/vmalloc.c 2009-06-24 16:05:47.000000000 +0200
@@ -1368,7 +1368,7 @@ void *vmap(struct page **pages, unsigned

might_sleep();

- if (count > num_physpages)
+ if (count > totalram_pages)
return NULL;

area = get_vm_area_caller((count << PAGE_SHIFT), flags,
@@ -1475,7 +1475,7 @@ static void *__vmalloc_node(unsigned lon
unsigned long real_size = size;

size = PAGE_ALIGN(size);
- if (!size || (size >> PAGE_SHIFT) > num_physpages)
+ if (!size || (size >> PAGE_SHIFT) > totalram_pages)
return NULL;

area = __get_vm_area_node(size, VM_ALLOC, VMALLOC_START, VMALLOC_END,
--- linux-2.6.31-rc1/net/core/sock.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/core/sock.c 2009-06-24 16:14:00.000000000 +0200
@@ -1169,12 +1169,12 @@ EXPORT_SYMBOL_GPL(sk_setup_caps);

void __init sk_init(void)
{
- if (num_physpages <= 4096) {
+ if (totalram_pages <= 4096) {
sysctl_wmem_max = 32767;
sysctl_rmem_max = 32767;
sysctl_wmem_default = 32767;
sysctl_rmem_default = 32767;
- } else if (num_physpages >= 131072) {
+ } else if (totalram_pages >= 131072) {
sysctl_wmem_max = 131071;
sysctl_rmem_max = 131071;
}
--- linux-2.6.31-rc1/net/dccp/proto.c 2009-06-10 05:05:27.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/dccp/proto.c 2009-06-24 16:13:35.000000000 +0200
@@ -1049,10 +1049,10 @@ static int __init dccp_init(void)
*
* The methodology is similar to that of the buffer cache.
*/
- if (num_physpages >= (128 * 1024))
- goal = num_physpages >> (21 - PAGE_SHIFT);
+ if (totalram_pages >= (128 * 1024))
+ goal = totalram_pages >> (21 - PAGE_SHIFT);
else
- goal = num_physpages >> (23 - PAGE_SHIFT);
+ goal = totalram_pages >> (23 - PAGE_SHIFT);

if (thash_entries)
goal = (thash_entries *
--- linux-2.6.31-rc1/net/decnet/dn_route.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/decnet/dn_route.c 2009-06-24 16:17:11.000000000 +0200
@@ -1750,7 +1750,7 @@ void __init dn_route_init(void)
dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
add_timer(&dn_route_timer);

- goal = num_physpages >> (26 - PAGE_SHIFT);
+ goal = totalram_pages >> (26 - PAGE_SHIFT);

for(order = 0; (1UL << order) < goal; order++)
/* NOTHING */;
--- linux-2.6.31-rc1/net/ipv4/route.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/ipv4/route.c 2009-06-24 16:14:48.000000000 +0200
@@ -3412,7 +3412,7 @@ int __init ip_rt_init(void)
alloc_large_system_hash("IP route cache",
sizeof(struct rt_hash_bucket),
rhash_entries,
- (num_physpages >= 128 * 1024) ?
+ (totalram_pages >= 128 * 1024) ?
15 : 17,
0,
&rt_hash_log,
--- linux-2.6.31-rc1/net/ipv4/tcp.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/ipv4/tcp.c 2009-06-24 16:14:24.000000000 +0200
@@ -2857,7 +2857,7 @@ void __init tcp_init(void)
alloc_large_system_hash("TCP established",
sizeof(struct inet_ehash_bucket),
thash_entries,
- (num_physpages >= 128 * 1024) ?
+ (totalram_pages >= 128 * 1024) ?
13 : 15,
0,
&tcp_hashinfo.ehash_size,
@@ -2874,7 +2874,7 @@ void __init tcp_init(void)
alloc_large_system_hash("TCP bind",
sizeof(struct inet_bind_hashbucket),
tcp_hashinfo.ehash_size,
- (num_physpages >= 128 * 1024) ?
+ (totalram_pages >= 128 * 1024) ?
13 : 15,
0,
&tcp_hashinfo.bhash_size,
--- linux-2.6.31-rc1/net/netfilter/nf_conntrack_core.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/netfilter/nf_conntrack_core.c 2009-06-24 16:16:47.000000000 +0200
@@ -1230,9 +1230,9 @@ static int nf_conntrack_init_init_net(vo
* machine has 512 buckets. >= 1GB machines have 16384 buckets. */
if (!nf_conntrack_htable_size) {
nf_conntrack_htable_size
- = (((num_physpages << PAGE_SHIFT) / 16384)
+ = (((totalram_pages << PAGE_SHIFT) / 16384)
/ sizeof(struct hlist_head));
- if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
+ if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
nf_conntrack_htable_size = 16384;
if (nf_conntrack_htable_size < 32)
nf_conntrack_htable_size = 32;
--- linux-2.6.31-rc1/net/netfilter/x_tables.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/netfilter/x_tables.c 2009-06-24 16:16:28.000000000 +0200
@@ -617,7 +617,7 @@ struct xt_table_info *xt_alloc_table_inf
int cpu;

/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
- if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
+ if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
return NULL;

newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
--- linux-2.6.31-rc1/net/netfilter/xt_hashlimit.c 2009-06-10 05:05:27.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/netfilter/xt_hashlimit.c 2009-06-24 16:16:07.000000000 +0200
@@ -194,9 +194,9 @@ static int htable_create_v0(struct xt_ha
if (minfo->cfg.size)
size = minfo->cfg.size;
else {
- size = ((num_physpages << PAGE_SHIFT) / 16384) /
+ size = ((totalram_pages << PAGE_SHIFT) / 16384) /
sizeof(struct list_head);
- if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
+ if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
size = 8192;
if (size < 16)
size = 16;
@@ -266,9 +266,9 @@ static int htable_create(struct xt_hashl
if (minfo->cfg.size) {
size = minfo->cfg.size;
} else {
- size = (num_physpages << PAGE_SHIFT) / 16384 /
+ size = (totalram_pages << PAGE_SHIFT) / 16384 /
sizeof(struct list_head);
- if (num_physpages > 1024 * 1024 * 1024 / PAGE_SIZE)
+ if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE)
size = 8192;
if (size < 16)
size = 16;
--- linux-2.6.31-rc1/net/netlink/af_netlink.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/netlink/af_netlink.c 2009-06-24 16:17:28.000000000 +0200
@@ -2026,10 +2026,10 @@ static int __init netlink_proto_init(voi
if (!nl_table)
goto panic;

- if (num_physpages >= (128 * 1024))
- limit = num_physpages >> (21 - PAGE_SHIFT);
+ if (totalram_pages >= (128 * 1024))
+ limit = totalram_pages >> (21 - PAGE_SHIFT);
else
- limit = num_physpages >> (23 - PAGE_SHIFT);
+ limit = totalram_pages >> (23 - PAGE_SHIFT);

order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
limit = (1UL << order) / sizeof(struct hlist_head);
--- linux-2.6.31-rc1/net/sctp/protocol.c 2009-06-26 17:50:00.000000000 +0200
+++ 2.6.31-rc1-use-totalram_pages/net/sctp/protocol.c 2009-06-24 16:15:36.000000000 +0200
@@ -1185,10 +1185,10 @@ SCTP_STATIC __init int sctp_init(void)
/* Size and allocate the association hash table.
* The methodology is similar to that of the tcp hash tables.
*/
- if (num_physpages >= (128 * 1024))
- goal = num_physpages >> (22 - PAGE_SHIFT);
+ if (totalram_pages >= (128 * 1024))
+ goal = totalram_pages >> (22 - PAGE_SHIFT);
else
- goal = num_physpages >> (24 - PAGE_SHIFT);
+ goal = totalram_pages >> (24 - PAGE_SHIFT);

for (order = 0; (1UL << order) < goal; order++)
;


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