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Diffstat (limited to 'mm')
-rw-r--r--mm/khugepaged.c2
-rw-r--r--mm/ksm.c12
-rw-r--r--mm/memory.c5
3 files changed, 18 insertions, 1 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 78c8d5d8b628..419981dcc889 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -19,6 +19,7 @@
#include <linux/page_table_check.h>
#include <linux/swapops.h>
#include <linux/shmem_fs.h>
+#include <linux/ksm.h>
#include <asm/tlb.h>
#include <asm/pgalloc.h>
@@ -709,6 +710,7 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
spin_lock(ptl);
ptep_clear(vma->vm_mm, address, _pte);
spin_unlock(ptl);
+ ksm_might_unmap_zero_page(pteval);
}
} else {
src_page = pte_page(pteval);
diff --git a/mm/ksm.c b/mm/ksm.c
index 99519e22a761..e037d9aad691 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -278,6 +278,9 @@ static unsigned int zero_checksum __read_mostly;
/* Whether to merge empty (zeroed) pages with actual zero pages */
static bool ksm_use_zero_pages __read_mostly;
+/* The number of zero pages which is placed by KSM */
+unsigned long ksm_zero_pages;
+
#ifdef CONFIG_NUMA
/* Zeroed when merging across nodes is not allowed */
static unsigned int ksm_merge_across_nodes = 1;
@@ -1229,6 +1232,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
* the dirty bit in zero page's PTE is set.
*/
newpte = pte_mkdirty(pte_mkspecial(pfn_pte(page_to_pfn(kpage), vma->vm_page_prot)));
+ ksm_zero_pages++;
/*
* We're replacing an anonymous page with a zero page, which is
* not anonymous. We need to do proper accounting otherwise we
@@ -3356,6 +3360,13 @@ static ssize_t pages_volatile_show(struct kobject *kobj,
}
KSM_ATTR_RO(pages_volatile);
+static ssize_t ksm_zero_pages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%ld\n", ksm_zero_pages);
+}
+KSM_ATTR_RO(ksm_zero_pages);
+
static ssize_t general_profit_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
@@ -3423,6 +3434,7 @@ static struct attribute *ksm_attrs[] = {
&pages_sharing_attr.attr,
&pages_unshared_attr.attr,
&pages_volatile_attr.attr,
+ &ksm_zero_pages_attr.attr,
&full_scans_attr.attr,
#ifdef CONFIG_NUMA
&merge_across_nodes_attr.attr,
diff --git a/mm/memory.c b/mm/memory.c
index e9f9944c7370..c256da05bb5e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1433,8 +1433,10 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
tlb_remove_tlb_entry(tlb, pte, addr);
zap_install_uffd_wp_if_needed(vma, addr, pte, details,
ptent);
- if (unlikely(!page))
+ if (unlikely(!page)) {
+ ksm_might_unmap_zero_page(ptent);
continue;
+ }
delay_rmap = 0;
if (!PageAnon(page)) {
@@ -3128,6 +3130,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
inc_mm_counter(mm, MM_ANONPAGES);
}
} else {
+ ksm_might_unmap_zero_page(vmf->orig_pte);
inc_mm_counter(mm, MM_ANONPAGES);
}
flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));