As pages are faulted in MLOCK_ONFAULT correctly updates
/proc/self/smaps, but doesn't update /proc/meminfo's Mlocked field.
- Before this /proc/meminfo fields didn't change as pages were faulted in:
```
= Start =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
= Creating testfile =
= after mlock2(MLOCK_ONFAULT) =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
Locked: 0 kB
= after reading half of the file =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
Locked: 524288 kB
= after reading the entire the file =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
Locked: 1048576 kB
= after munmap =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
```
- After: /proc/meminfo fields are properly updated as pages are touched:
```
= Start =
/proc/meminfo
Unevictable: 60 kB
Mlocked: 60 kB
= Creating testfile =
= after mlock2(MLOCK_ONFAULT) =
/proc/meminfo
Unevictable: 60 kB
Mlocked: 60 kB
/proc/self/smaps
7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
Locked: 0 kB
= after reading half of the file =
/proc/meminfo
Unevictable: 524220 kB
Mlocked: 524220 kB
/proc/self/smaps
7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
Locked: 524288 kB
= after reading the entire the file =
/proc/meminfo
Unevictable: 1048496 kB
Mlocked: 1048508 kB
/proc/self/smaps
7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
Locked: 1048576 kB
= after munmap =
/proc/meminfo
Unevictable: 176 kB
Mlocked: 60 kB
/proc/self/smaps
```
Repro code.
---
int mlock2wrap(const void* addr, size_t len, int flags) {
return syscall(SYS_mlock2, addr, len, flags);
}
void smaps() {
char smapscmd[1000];
snprintf(
smapscmd,
sizeof(smapscmd) - 1,
"grep testfile -A 20 /proc/%d/smaps | grep -E '(testfile|Locked)'",
getpid());
printf("/proc/self/smaps\n");
fflush(stdout);
system(smapscmd);
}
void meminfo() {
const char* meminfocmd = "grep -E '(Mlocked|Unevictable)' /proc/meminfo";
printf("/proc/meminfo\n");
fflush(stdout);
system(meminfocmd);
}
{ \
int rc = (call); \
if (rc != 0) { \
printf("error %d %s\n", rc, strerror(errno)); \
exit(1); \
} \
}
int main(int argc, char* argv[]) {
printf("= Start =\n");
meminfo();
printf("= Creating testfile =\n");
size_t size = 1 << 30; // 1 GiB
int fd = open("testfile", O_CREAT | O_RDWR, 0666);
{
void* buf = malloc(size);
write(fd, buf, size);
free(buf);
}
int ret = 0;
void* addr = NULL;
addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (argc > 1) {
PCHECK(mlock2wrap(addr, size, MLOCK_ONFAULT));
printf("= after mlock2(MLOCK_ONFAULT) =\n");
meminfo();
smaps();
for (size_t i = 0; i < size / 2; i += 4096) {
ret += ((char*)addr)[i];
}
printf("= after reading half of the file =\n");
meminfo();
smaps();
for (size_t i = 0; i < size; i += 4096) {
ret += ((char*)addr)[i];
}
printf("= after reading the entire the file =\n");
meminfo();
smaps();
} else {
PCHECK(mlock(addr, size));
printf("= after mlock =\n");
meminfo();
smaps();
}
PCHECK(munmap(addr, size));
printf("= after munmap =\n");
meminfo();
smaps();
return ret;
}
---
Signed-off-by: Lucian Adrian Grijincu <[email protected]>
---
mm/memory.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/memory.c b/mm/memory.c
index e0c232fe81d9..7e8dc3ed4e89 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3311,6 +3311,9 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
} else {
inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page));
page_add_file_rmap(page, false);
+ if ((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) == VM_LOCKED &&
+ !PageTransCompound(page))
+ mlock_vma_page(page);
}
set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry);
--
2.17.1
On Fri, Sep 13, 2019 at 4:49 AM Lucian Adrian Grijincu <[email protected]> wrote:
>
> As pages are faulted in MLOCK_ONFAULT correctly updates
> /proc/self/smaps, but doesn't update /proc/meminfo's Mlocked field.
>
> - Before this /proc/meminfo fields didn't change as pages were faulted in:
>
> ```
> = Start =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> = Creating testfile =
>
> = after mlock2(MLOCK_ONFAULT) =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> 7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
> Locked: 0 kB
>
> = after reading half of the file =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> 7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
> Locked: 524288 kB
>
> = after reading the entire the file =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> 7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
> Locked: 1048576 kB
>
> = after munmap =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> ```
>
> - After: /proc/meminfo fields are properly updated as pages are touched:
>
> ```
> = Start =
> /proc/meminfo
> Unevictable: 60 kB
> Mlocked: 60 kB
> = Creating testfile =
>
> = after mlock2(MLOCK_ONFAULT) =
> /proc/meminfo
> Unevictable: 60 kB
> Mlocked: 60 kB
> /proc/self/smaps
> 7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
> Locked: 0 kB
>
> = after reading half of the file =
> /proc/meminfo
> Unevictable: 524220 kB
> Mlocked: 524220 kB
> /proc/self/smaps
> 7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
> Locked: 524288 kB
>
> = after reading the entire the file =
> /proc/meminfo
> Unevictable: 1048496 kB
> Mlocked: 1048508 kB
> /proc/self/smaps
> 7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
> Locked: 1048576 kB
>
> = after munmap =
> /proc/meminfo
> Unevictable: 176 kB
> Mlocked: 60 kB
> /proc/self/smaps
> ```
>
> Repro code.
> ---
>
> int mlock2wrap(const void* addr, size_t len, int flags) {
> return syscall(SYS_mlock2, addr, len, flags);
> }
>
> void smaps() {
> char smapscmd[1000];
> snprintf(
> smapscmd,
> sizeof(smapscmd) - 1,
> "grep testfile -A 20 /proc/%d/smaps | grep -E '(testfile|Locked)'",
> getpid());
> printf("/proc/self/smaps\n");
> fflush(stdout);
> system(smapscmd);
> }
>
> void meminfo() {
> const char* meminfocmd = "grep -E '(Mlocked|Unevictable)' /proc/meminfo";
> printf("/proc/meminfo\n");
> fflush(stdout);
> system(meminfocmd);
> }
>
> { \
> int rc = (call); \
> if (rc != 0) { \
> printf("error %d %s\n", rc, strerror(errno)); \
> exit(1); \
> } \
> }
> int main(int argc, char* argv[]) {
> printf("= Start =\n");
> meminfo();
>
> printf("= Creating testfile =\n");
> size_t size = 1 << 30; // 1 GiB
> int fd = open("testfile", O_CREAT | O_RDWR, 0666);
> {
> void* buf = malloc(size);
> write(fd, buf, size);
> free(buf);
> }
> int ret = 0;
> void* addr = NULL;
> addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
>
> if (argc > 1) {
> PCHECK(mlock2wrap(addr, size, MLOCK_ONFAULT));
> printf("= after mlock2(MLOCK_ONFAULT) =\n");
> meminfo();
> smaps();
>
> for (size_t i = 0; i < size / 2; i += 4096) {
> ret += ((char*)addr)[i];
> }
> printf("= after reading half of the file =\n");
> meminfo();
> smaps();
>
> for (size_t i = 0; i < size; i += 4096) {
> ret += ((char*)addr)[i];
> }
> printf("= after reading the entire the file =\n");
> meminfo();
> smaps();
>
> } else {
> PCHECK(mlock(addr, size));
> printf("= after mlock =\n");
> meminfo();
> smaps();
> }
>
> PCHECK(munmap(addr, size));
> printf("= after munmap =\n");
> meminfo();
> smaps();
>
> return ret;
> }
>
> ---
>
> Signed-off-by: Lucian Adrian Grijincu <[email protected]>
> ---
> mm/memory.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index e0c232fe81d9..7e8dc3ed4e89 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3311,6 +3311,9 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> } else {
> inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page));
> page_add_file_rmap(page, false);
> + if ((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) == VM_LOCKED &&
> + !PageTransCompound(page))
Do we need to check against VM_SPECIAL ?
> + mlock_vma_page(page);
> }
> set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry);
>
> --
> 2.17.1
>
>
As pages are faulted in MLOCK_ONFAULT correctly updates
/proc/self/smaps, but doesn't update /proc/meminfo's Mlocked field.
- Before this /proc/meminfo fields didn't change as pages were faulted in:
```
= Start =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
= Creating testfile =
= after mlock2(MLOCK_ONFAULT) =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
Locked: 0 kB
= after reading half of the file =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
Locked: 524288 kB
= after reading the entire the file =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
Locked: 1048576 kB
= after munmap =
/proc/meminfo
Unevictable: 10128 kB
Mlocked: 10132 kB
/proc/self/smaps
```
- After: /proc/meminfo fields are properly updated as pages are touched:
```
= Start =
/proc/meminfo
Unevictable: 60 kB
Mlocked: 60 kB
= Creating testfile =
= after mlock2(MLOCK_ONFAULT) =
/proc/meminfo
Unevictable: 60 kB
Mlocked: 60 kB
/proc/self/smaps
7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
Locked: 0 kB
= after reading half of the file =
/proc/meminfo
Unevictable: 524220 kB
Mlocked: 524220 kB
/proc/self/smaps
7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
Locked: 524288 kB
= after reading the entire the file =
/proc/meminfo
Unevictable: 1048496 kB
Mlocked: 1048508 kB
/proc/self/smaps
7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
Locked: 1048576 kB
= after munmap =
/proc/meminfo
Unevictable: 176 kB
Mlocked: 60 kB
/proc/self/smaps
```
Repro code.
---
int mlock2wrap(const void* addr, size_t len, int flags) {
return syscall(SYS_mlock2, addr, len, flags);
}
void smaps() {
char smapscmd[1000];
snprintf(
smapscmd,
sizeof(smapscmd) - 1,
"grep testfile -A 20 /proc/%d/smaps | grep -E '(testfile|Locked)'",
getpid());
printf("/proc/self/smaps\n");
fflush(stdout);
system(smapscmd);
}
void meminfo() {
const char* meminfocmd = "grep -E '(Mlocked|Unevictable)' /proc/meminfo";
printf("/proc/meminfo\n");
fflush(stdout);
system(meminfocmd);
}
{ \
int rc = (call); \
if (rc != 0) { \
printf("error %d %s\n", rc, strerror(errno)); \
exit(1); \
} \
}
int main(int argc, char* argv[]) {
printf("= Start =\n");
meminfo();
printf("= Creating testfile =\n");
size_t size = 1 << 30; // 1 GiB
int fd = open("testfile", O_CREAT | O_RDWR, 0666);
{
void* buf = malloc(size);
write(fd, buf, size);
free(buf);
}
int ret = 0;
void* addr = NULL;
addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (argc > 1) {
PCHECK(mlock2wrap(addr, size, MLOCK_ONFAULT));
printf("= after mlock2(MLOCK_ONFAULT) =\n");
meminfo();
smaps();
for (size_t i = 0; i < size / 2; i += 4096) {
ret += ((char*)addr)[i];
}
printf("= after reading half of the file =\n");
meminfo();
smaps();
for (size_t i = 0; i < size; i += 4096) {
ret += ((char*)addr)[i];
}
printf("= after reading the entire the file =\n");
meminfo();
smaps();
} else {
PCHECK(mlock(addr, size));
printf("= after mlock =\n");
meminfo();
smaps();
}
PCHECK(munmap(addr, size));
printf("= after munmap =\n");
meminfo();
smaps();
return ret;
}
---
Signed-off-by: Lucian Adrian Grijincu <[email protected]>
---
mm/memory.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/mm/memory.c b/mm/memory.c
index e0c232fe81d9..55da24f33bc4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3311,6 +3311,8 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
} else {
inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page));
page_add_file_rmap(page, false);
+ if (vma->vm_flags & VM_LOCKED && !PageTransCompound(page))
+ mlock_vma_page(page);
}
set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry);
--
2.17.1
On 9/13/19, 04:18, "Souptick Joarder" <[email protected]> wrote:
On Fri, Sep 13, 2019 at 4:49 AM Lucian Adrian Grijincu <[email protected]> wrote:
>
> As pages are faulted in MLOCK_ONFAULT correctly updates
> /proc/self/smaps, but doesn't update /proc/meminfo's Mlocked field.
>
> - Before this /proc/meminfo fields didn't change as pages were faulted in:
> diff --git a/mm/memory.c b/mm/memory.c
> index e0c232fe81d9..7e8dc3ed4e89 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3311,6 +3311,9 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> } else {
> inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page));
> page_add_file_rmap(page, false);
> + if ((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) == VM_LOCKED &&
> + !PageTransCompound(page))
Do we need to check against VM_SPECIAL ?
I think you're right. mlock/mlock2 already checks and doesn't set VM_LOCKED if VM_SPECIAL is set: https://github.com/torvalds/linux/blob/v5.2/mm/mlock.c#L519-L533
/*
* mlock_fixup - handle mlock[all]/munlock[all] requests.
*
* Filters out "special" vmas -- VM_LOCKED never gets set for these, and
* munlock is a no-op. However, for some special vmas, we go ahead and
* populate the ptes.
*
* For vmas that pass the filters, merge/split as appropriate.
*/
static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
unsigned long start, unsigned long end, vm_flags_t newflags)
{
struct mm_struct *mm = vma->vm_mm;
pgoff_t pgoff;
int nr_pages;
int ret = 0;
int lock = !!(newflags & VM_LOCKED);
vm_flags_t old_flags = vma->vm_flags;
if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) ||
vma_is_dax(vma))
/* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */
goto out;
I got thrown off by this check https://github.com/torvalds/linux/blob/v5.2/mm/swap.c#L454-L469
void lru_cache_add_active_or_unevictable(struct page *page,
struct vm_area_struct *vma)
{
VM_BUG_ON_PAGE(PageLRU(page), page);
if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
SetPageActive(page);
else if (!TestSetPageMlocked(page)) {
/*
* We use the irq-unsafe __mod_zone_page_stat because this
* counter is not modified from interrupt context, and the pte
* lock is held(spinlock), which implies preemption disabled.
*/
__mod_zone_page_state(page_zone(page), NR_MLOCK,
hpage_nr_pages(page));
count_vm_event(UNEVICTABLE_PGMLOCKED);
I'll remove VM_SPECIAL and re-submit.
--
Lucian
On Sat, Sep 14, 2019 at 12:59 AM Lucian Adrian Grijincu <[email protected]> wrote:
>
> As pages are faulted in MLOCK_ONFAULT correctly updates
> /proc/self/smaps, but doesn't update /proc/meminfo's Mlocked field.
>
> - Before this /proc/meminfo fields didn't change as pages were faulted in:
>
> ```
> = Start =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> = Creating testfile =
>
> = after mlock2(MLOCK_ONFAULT) =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> 7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
> Locked: 0 kB
>
> = after reading half of the file =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> 7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
> Locked: 524288 kB
>
> = after reading the entire the file =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> 7f8714000000-7f8754000000 rw-s 00000000 08:04 50857050 /root/testfile
> Locked: 1048576 kB
>
> = after munmap =
> /proc/meminfo
> Unevictable: 10128 kB
> Mlocked: 10132 kB
> /proc/self/smaps
> ```
>
> - After: /proc/meminfo fields are properly updated as pages are touched:
>
> ```
> = Start =
> /proc/meminfo
> Unevictable: 60 kB
> Mlocked: 60 kB
> = Creating testfile =
>
> = after mlock2(MLOCK_ONFAULT) =
> /proc/meminfo
> Unevictable: 60 kB
> Mlocked: 60 kB
> /proc/self/smaps
> 7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
> Locked: 0 kB
>
> = after reading half of the file =
> /proc/meminfo
> Unevictable: 524220 kB
> Mlocked: 524220 kB
> /proc/self/smaps
> 7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
> Locked: 524288 kB
>
> = after reading the entire the file =
> /proc/meminfo
> Unevictable: 1048496 kB
> Mlocked: 1048508 kB
> /proc/self/smaps
> 7f2b9c600000-7f2bdc600000 rw-s 00000000 08:04 63045798 /root/testfile
> Locked: 1048576 kB
>
> = after munmap =
> /proc/meminfo
> Unevictable: 176 kB
> Mlocked: 60 kB
> /proc/self/smaps
> ```
>
> Repro code.
> ---
>
> int mlock2wrap(const void* addr, size_t len, int flags) {
> return syscall(SYS_mlock2, addr, len, flags);
> }
>
> void smaps() {
> char smapscmd[1000];
> snprintf(
> smapscmd,
> sizeof(smapscmd) - 1,
> "grep testfile -A 20 /proc/%d/smaps | grep -E '(testfile|Locked)'",
> getpid());
> printf("/proc/self/smaps\n");
> fflush(stdout);
> system(smapscmd);
> }
>
> void meminfo() {
> const char* meminfocmd = "grep -E '(Mlocked|Unevictable)' /proc/meminfo";
> printf("/proc/meminfo\n");
> fflush(stdout);
> system(meminfocmd);
> }
>
> { \
> int rc = (call); \
> if (rc != 0) { \
> printf("error %d %s\n", rc, strerror(errno)); \
> exit(1); \
> } \
> }
> int main(int argc, char* argv[]) {
> printf("= Start =\n");
> meminfo();
>
> printf("= Creating testfile =\n");
> size_t size = 1 << 30; // 1 GiB
> int fd = open("testfile", O_CREAT | O_RDWR, 0666);
> {
> void* buf = malloc(size);
> write(fd, buf, size);
> free(buf);
> }
> int ret = 0;
> void* addr = NULL;
> addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
>
> if (argc > 1) {
> PCHECK(mlock2wrap(addr, size, MLOCK_ONFAULT));
> printf("= after mlock2(MLOCK_ONFAULT) =\n");
> meminfo();
> smaps();
>
> for (size_t i = 0; i < size / 2; i += 4096) {
> ret += ((char*)addr)[i];
> }
> printf("= after reading half of the file =\n");
> meminfo();
> smaps();
>
> for (size_t i = 0; i < size; i += 4096) {
> ret += ((char*)addr)[i];
> }
> printf("= after reading the entire the file =\n");
> meminfo();
> smaps();
>
> } else {
> PCHECK(mlock(addr, size));
> printf("= after mlock =\n");
> meminfo();
> smaps();
> }
>
> PCHECK(munmap(addr, size));
> printf("= after munmap =\n");
> meminfo();
> smaps();
>
> return ret;
> }
>
> ---
>
> Signed-off-by: Lucian Adrian Grijincu <[email protected]>
Acked-by: Souptick Joarder <[email protected]>
(For the comment on v1)
Patch version need to be change to v2.
> ---
> mm/memory.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index e0c232fe81d9..55da24f33bc4 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3311,6 +3311,8 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> } else {
> inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page));
> page_add_file_rmap(page, false);
> + if (vma->vm_flags & VM_LOCKED && !PageTransCompound(page))
> + mlock_vma_page(page);
> }
> set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry);
>
> --
> 2.17.1
>