mm: convert totalram_pages and totalhigh_pages variables to atomic
totalram_pages and totalhigh_pages are made static inline function.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.
[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/highmem.c b/mm/highmem.c
index 59db322..107b10f 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -105,9 +105,8 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
}
#endif
-unsigned long totalhigh_pages __read_mostly;
-EXPORT_SYMBOL(totalhigh_pages);
-
+atomic_long_t _totalhigh_pages __read_mostly;
+EXPORT_SYMBOL(_totalhigh_pages);
EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index e84a10b..da6682b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -420,7 +420,7 @@ static int __init hugepage_init(void)
* where the extra memory used could hurt more than TLB overhead
* is likely to save. The admin can still enable it through /sys.
*/
- if (totalram_pages < (512 << (20 - PAGE_SHIFT))) {
+ if (totalram_pages() < (512 << (20 - PAGE_SHIFT))) {
transparent_hugepage_flags = 0;
return 0;
}
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 57334ef..978bc4a3 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -237,7 +237,7 @@ void quarantine_reduce(void)
* Update quarantine size in case of hotplug. Allocate a fraction of
* the installed memory to quarantine minus per-cpu queue limits.
*/
- total_size = (READ_ONCE(totalram_pages) << PAGE_SHIFT) /
+ total_size = (totalram_pages() << PAGE_SHIFT) /
QUARANTINE_FRACTION;
percpu_quarantines = QUARANTINE_PERCPU_SIZE * num_online_cpus();
new_quarantine_size = (total_size < percpu_quarantines) ?
diff --git a/mm/memblock.c b/mm/memblock.c
index 0068f87..a53d869 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1576,7 +1576,7 @@ void __init __memblock_free_late(phys_addr_t base, phys_addr_t size)
for (; cursor < end; cursor++) {
memblock_free_pages(pfn_to_page(cursor), cursor, 0);
- totalram_pages++;
+ totalram_pages_inc();
}
}
@@ -1978,7 +1978,7 @@ unsigned long __init memblock_free_all(void)
reset_all_zones_managed_pages();
pages = free_low_memory_core_early();
- totalram_pages += pages;
+ totalram_pages_add(pages);
return pages;
}
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 6838a53..3391710 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -146,7 +146,7 @@ static void __meminit mm_compute_batch(void)
s32 batch = max_t(s32, nr*2, 32);
/* batch size set to 0.4% of (total memory/#cpus), or max int32 */
- memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
+ memsized_batch = min_t(u64, (totalram_pages()/nr)/256, 0x7fffffff);
vm_committed_as_batch = max_t(s32, memsized_batch, batch);
}
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 6589f60..21d4877 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -269,7 +269,7 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)
}
/* Default to all available memory */
- oc->totalpages = totalram_pages + total_swap_pages;
+ oc->totalpages = totalram_pages() + total_swap_pages;
if (!IS_ENABLED(CONFIG_NUMA))
return CONSTRAINT_NONE;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4b5c4ff..eb20278 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -16,6 +16,7 @@
#include <linux/stddef.h>
#include <linux/mm.h>
+#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
@@ -124,7 +125,8 @@ EXPORT_SYMBOL(node_states);
/* Protect totalram_pages and zone->managed_pages */
static DEFINE_SPINLOCK(managed_page_count_lock);
-unsigned long totalram_pages __read_mostly;
+atomic_long_t _totalram_pages __read_mostly;
+EXPORT_SYMBOL(_totalram_pages);
unsigned long totalreserve_pages __read_mostly;
unsigned long totalcma_pages __read_mostly;
@@ -4747,11 +4749,11 @@ EXPORT_SYMBOL_GPL(si_mem_available);
void si_meminfo(struct sysinfo *val)
{
- val->totalram = totalram_pages;
+ val->totalram = totalram_pages();
val->sharedram = global_node_page_state(NR_SHMEM);
val->freeram = global_zone_page_state(NR_FREE_PAGES);
val->bufferram = nr_blockdev_pages();
- val->totalhigh = totalhigh_pages;
+ val->totalhigh = totalhigh_pages();
val->freehigh = nr_free_highpages();
val->mem_unit = PAGE_SIZE;
}
@@ -7077,10 +7079,10 @@ void adjust_managed_page_count(struct page *page, long count)
{
spin_lock(&managed_page_count_lock);
atomic_long_add(count, &page_zone(page)->managed_pages);
- totalram_pages += count;
+ totalram_pages_add(count);
#ifdef CONFIG_HIGHMEM
if (PageHighMem(page))
- totalhigh_pages += count;
+ totalhigh_pages_add(count);
#endif
spin_unlock(&managed_page_count_lock);
}
@@ -7123,9 +7125,9 @@ EXPORT_SYMBOL(free_reserved_area);
void free_highmem_page(struct page *page)
{
__free_reserved_page(page);
- totalram_pages++;
+ totalram_pages_inc();
atomic_long_inc(&page_zone(page)->managed_pages);
- totalhigh_pages++;
+ totalhigh_pages_inc();
}
#endif
@@ -7174,10 +7176,10 @@ void __init mem_init_print_info(const char *str)
physpages << (PAGE_SHIFT - 10),
codesize >> 10, datasize >> 10, rosize >> 10,
(init_data_size + init_code_size) >> 10, bss_size >> 10,
- (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
+ (physpages - totalram_pages() - totalcma_pages) << (PAGE_SHIFT - 10),
totalcma_pages << (PAGE_SHIFT - 10),
#ifdef CONFIG_HIGHMEM
- totalhigh_pages << (PAGE_SHIFT - 10),
+ totalhigh_pages() << (PAGE_SHIFT - 10),
#endif
str ? ", " : "", str ? str : "");
}
diff --git a/mm/shmem.c b/mm/shmem.c
index b1f0f54..6ece1e2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -109,13 +109,14 @@ struct shmem_falloc {
#ifdef CONFIG_TMPFS
static unsigned long shmem_default_max_blocks(void)
{
- return totalram_pages / 2;
+ return totalram_pages() / 2;
}
static unsigned long shmem_default_max_inodes(void)
{
- unsigned long nr_pages = totalram_pages;
- return min(nr_pages - totalhigh_pages, nr_pages / 2);
+ unsigned long nr_pages = totalram_pages();
+
+ return min(nr_pages - totalhigh_pages(), nr_pages / 2);
}
#endif
@@ -3302,7 +3303,7 @@ static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
size = memparse(value,&rest);
if (*rest == '%') {
size <<= PAGE_SHIFT;
- size *= totalram_pages;
+ size *= totalram_pages();
do_div(size, 100);
rest++;
}
diff --git a/mm/slab.c b/mm/slab.c
index 0199106..73fe23e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1235,7 +1235,7 @@ void __init kmem_cache_init(void)
* page orders on machines with more than 32MB of memory if
* not overridden on the command line.
*/
- if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT)
+ if (!slab_max_order_set && totalram_pages() > (32 << 20) >> PAGE_SHIFT)
slab_max_order = SLAB_MAX_ORDER_HI;
/* Bootstrap is tricky, because several objects are allocated
diff --git a/mm/swap.c b/mm/swap.c
index 5d78601..4d8a1f1 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -1022,7 +1022,7 @@ EXPORT_SYMBOL(pagevec_lookup_range_nr_tag);
*/
void __init swap_setup(void)
{
- unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT);
+ unsigned long megs = totalram_pages() >> (20 - PAGE_SHIFT);
/* Use a smaller cluster for small-memory machines */
if (megs < 16)
diff --git a/mm/util.c b/mm/util.c
index 8bf08b5..4df23d6 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -593,7 +593,7 @@ unsigned long vm_commit_limit(void)
if (sysctl_overcommit_kbytes)
allowed = sysctl_overcommit_kbytes >> (PAGE_SHIFT - 10);
else
- allowed = ((totalram_pages - hugetlb_total_pages())
+ allowed = ((totalram_pages() - hugetlb_total_pages())
* sysctl_overcommit_ratio / 100);
allowed += total_swap_pages;
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 97d4b25..871e41c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1634,7 +1634,7 @@ void *vmap(struct page **pages, unsigned int count,
might_sleep();
- if (count > totalram_pages)
+ if (count > totalram_pages())
return NULL;
size = (unsigned long)count << PAGE_SHIFT;
@@ -1739,7 +1739,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
unsigned long real_size = size;
size = PAGE_ALIGN(size);
- if (!size || (size >> PAGE_SHIFT) > totalram_pages)
+ if (!size || (size >> PAGE_SHIFT) > totalram_pages())
goto fail;
area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
diff --git a/mm/workingset.c b/mm/workingset.c
index d46f8c9..dcb994f 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -549,7 +549,7 @@ static int __init workingset_init(void)
* double the initial memory by using totalram_pages as-is.
*/
timestamp_bits = BITS_PER_LONG - EVICTION_SHIFT;
- max_order = fls_long(totalram_pages - 1);
+ max_order = fls_long(totalram_pages() - 1);
if (max_order > timestamp_bits)
bucket_order = max_order - timestamp_bits;
pr_info("workingset: timestamp_bits=%d max_order=%d bucket_order=%u\n",
diff --git a/mm/zswap.c b/mm/zswap.c
index cd91fd9d..a4e4d36 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -219,8 +219,8 @@ static const struct zpool_ops zswap_zpool_ops = {
static bool zswap_is_full(void)
{
- return totalram_pages * zswap_max_pool_percent / 100 <
- DIV_ROUND_UP(zswap_pool_total_size, PAGE_SIZE);
+ return totalram_pages() * zswap_max_pool_percent / 100 <
+ DIV_ROUND_UP(zswap_pool_total_size, PAGE_SIZE);
}
static void zswap_update_total_size(void)
