On 2023/7/6 19:58, Xiao Yang wrote:
> On 2023/7/6 14:39, Miaohe Lin wrote:
>> It appears that destroy_memory_type() isn't a very good name because
>> we usually will not free the memory_type here. So rename it to a more
>> appropriate name i.e. put_memory_type().
>>
&
It appears that destroy_memory_type() isn't a very good name because
we usually will not free the memory_type here. So rename it to a more
appropriate name i.e. put_memory_type().
Suggested-by: Huang, Ying
Signed-off-by: Miaohe Lin
---
drivers/dax/kmem.c | 4 ++--
include/linux
s Zhou and Tim Chen.
Miaohe Lin (4):
mm/swapfile: use percpu_ref to serialize against concurrent swapoff
swap: fix do_swap_page() race with swapoff
mm/swap: remove confusing checking for non_swap_entry() in
swap_ra_info()
mm/shmem: fix shmem_swapin() race with swapoff
include/linux/
: 0bcac06f27d7 ("mm,swap: skip swapcache for swapin of synchronous device")
Reported-by: kernel test robot (auto build test ERROR)
Signed-off-by: Miaohe Lin
---
include/linux/swap.h | 9 +
mm/memory.c | 9 +
2 files changed, 18 insertions(+)
diff --git a/include/l
used together with RCU solution.
Signed-off-by: Miaohe Lin
---
include/linux/swap.h | 5 +--
mm/swapfile.c| 79 +++-
2 files changed, 52 insertions(+), 32 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 144727041e78
backing device is congested or
not")
Signed-off-by: Miaohe Lin
---
mm/shmem.c | 6 ++
1 file changed, 6 insertions(+)
diff --git a/mm/shmem.c b/mm/shmem.c
index 26c76b13ad23..936ba5595297 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1492,15 +1492,21 @@ static void shmem_pseudo_vma_des
cking when we really
operate the PTE entries later. So checking for non_swap_entry() is not
really needed here and should be removed to avoid confusion.
Signed-off-by: Miaohe Lin
---
mm/swap_state.c | 6 --
1 file changed, 6 deletions(-)
diff --git a/mm/swap_state.c b/mm/swap_state.
On 2021/4/19 15:52, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/19 15:09, Huang, Ying wrote:
>>> Miaohe Lin writes:
>>>
>>>> On 2021/4/19 10:48, Huang, Ying wrote:
>>>>> Miaohe Lin writes:
>>>>>
&g
On 2021/4/19 15:41, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/19 15:04, Huang, Ying wrote:
>>> Miaohe Lin writes:
>>>
>>>> On 2021/4/19 10:15, Huang, Ying wrote:
>>>>> Miaohe Lin writes:
>>>>>
>&g
On 2021/4/19 15:09, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/19 10:48, Huang, Ying wrote:
>>> Miaohe Lin writes:
>>>
>>>> We will use percpu-refcount to serialize against concurrent swapoff. This
>>>> patch adds the percpu_ref
On 2021/4/19 15:04, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/19 10:15, Huang, Ying wrote:
>>> Miaohe Lin writes:
>>>
>>>> When I was investigating the swap code, I found the below possible race
>>>> window:
>>&
On 2021/4/19 10:54, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> Use percpu_ref to serialize against concurrent swapoff. Also remove the
>> SWP_VALID flag because it's used together with RCU solution.
>>
>> Signed-off-by: Miaohe Lin
>> ---
>> inclu
On 2021/4/19 10:23, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> When I was investigating the swap code, I found the below possible race
>> window:
>>
>> CPU 1CPU 2
>> --
On 2021/4/19 10:15, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> When I was investigating the swap code, I found the below possible race
>> window:
>>
>> CPU 1 CPU 2
>> -
On 2021/4/19 9:53, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> While we released the pte lock, somebody else might faulted in this pte.
>> So we should check whether it's swap pte first to guard against such race
>> or swp_type would be unexpected. But t
On 2021/4/19 10:48, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> We will use percpu-refcount to serialize against concurrent swapoff. This
>> patch adds the percpu_ref support for swap.
>>
>> Signed-off-by: Miaohe Lin
>> ---
>> include/linux/swa
be found in the respective
changelogs. Thanks!
v1->v2:
reorganize the patch-2/5
various enhance and fixup per Huang, Ying
Many thanks for the comments of Huang, Ying, Dennis Zhou and Tim Chen.
Miaohe Lin (5):
mm/swapfile: add percpu_ref support for swap
mm/swapfile: use percpu_
ynchronize_rcu();
..
si->swap_file = NULL;
struct inode *inode = si->swap_file->f_mapping->host;[oops!]
Close this race window by using get/put_swap_device() to guard against
concurrent swapoff.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2"
p: skip swapcache for swapin of synchronous device")
Reported-by: kernel test robot (auto build test ERROR)
Signed-off-by: Miaohe Lin
---
include/linux/swap.h | 9 +
mm/memory.c | 9 +
2 files changed, 18 insertions(+)
diff --git a/include/linux/swap.h b/include/linux/swap.h
Use percpu_ref to serialize against concurrent swapoff. Also remove the
SWP_VALID flag because it's used together with RCU solution.
Signed-off-by: Miaohe Lin
---
include/linux/swap.h | 3 +--
mm/swapfile.c| 43 +--
2 files changed, 18 insertions
later. So checking for non_swap_entry() is not really needed here
and should be removed to avoid confusion.
Signed-off-by: Miaohe Lin
---
mm/swap_state.c | 6 --
1 file changed, 6 deletions(-)
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 272ea2108c9d..df5405384520 100644
--- a/mm
We will use percpu-refcount to serialize against concurrent swapoff. This
patch adds the percpu_ref support for swap.
Signed-off-by: Miaohe Lin
---
include/linux/swap.h | 3 +++
mm/swapfile.c| 33 +
2 files changed, 32 insertions(+), 4 deletions(-)
diff
On 2021/4/16 14:25, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/15 22:31, Dennis Zhou wrote:
>>> On Thu, Apr 15, 2021 at 01:24:31PM +0800, Huang, Ying wrote:
>>>> Dennis Zhou writes:
>>>>
>>>>> On Wed, Apr 14, 2021 at 01:
gt; On Wed, Apr 14, 2021 at 11:59:03AM +0800, Huang, Ying wrote:
>>>>>> Dennis Zhou writes:
>>>>>>
>>>>>>> Hello,
>>>>>>>
>>>>>>> On Wed, Apr 14, 2021 at 10:06:48AM +0800, Huang, Ying wrote:
>>>>
On 2021/4/15 12:20, Dennis Zhou wrote:
> On Thu, Apr 15, 2021 at 11:16:42AM +0800, Miaohe Lin wrote:
>> On 2021/4/14 22:53, Dennis Zhou wrote:
>>> On Wed, Apr 14, 2021 at 01:44:58PM +0800, Huang, Ying wrote:
>>>> Dennis Zhou writes:
>>>>
>>>>&
On 2021/4/15 0:13, Tim Chen wrote:
>
>
> On 4/13/21 6:04 PM, Huang, Ying wrote:
>> Tim Chen writes:
>>
>>> On 4/12/21 6:27 PM, Huang, Ying wrote:
>>>
This isn't the commit that introduces the race. You can use `git blame`
find out the correct commit. For this it's commit
lo,
>>>>>
>>>>> On Wed, Apr 14, 2021 at 10:06:48AM +0800, Huang, Ying wrote:
>>>>>> Miaohe Lin writes:
>>>>>>
>>>>>>> On 2021/4/14 9:17, Huang, Ying wrote:
>>>>>>>> Miaohe Lin writes:
>
On 2021/4/14 11:07, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/13 9:27, Huang, Ying wrote:
>>> Miaohe Lin writes:
>>>
>>>> When I was investigating the swap code, I found the below possible race
>>>> window:
>
On 2021/4/13 9:27, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> When I was investigating the swap code, I found the below possible race
>> window:
>>
>> CPU 1CPU 2
>> ---
On 2021/4/13 9:36, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> swap_cluster_readahead() could race with swapoff and might dereference
>> si->swap_file after it's released by swapoff. Close this race window by
>> using get/put_swap_device() pair.
>
> I think
On 2021/4/13 9:33, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> The function get_shadow_from_swap_cache() can race with swapoff, though
>> it's only called by do_swap_page() now.
>>
>> Fixes: aae466b0052e ("mm/swap: implement workingset detection for anonymous
On 2021/4/14 9:04, Huang, Ying wrote:
> Tim Chen writes:
>
>> On 4/12/21 6:27 PM, Huang, Ying wrote:
>>
>>>
>>> This isn't the commit that introduces the race. You can use `git blame`
>>> find out the correct commit. For this it's commit 0bcac06f27d7 "mm,
>>> swap: skip swapcache for swapin of
On 2021/4/14 9:17, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/12 15:24, Huang, Ying wrote:
>>> "Huang, Ying" writes:
>>>
>>>> Miaohe Lin writes:
>>>>
>>>>> We will use percpu-refcount to serialize aga
On 2021/4/12 15:24, Huang, Ying wrote:
> "Huang, Ying" writes:
>
>> Miaohe Lin writes:
>>
>>> We will use percpu-refcount to serialize against concurrent swapoff. This
>>> patch adds the percpu_ref support for later fixup.
>>>
>>&
On 2021/4/13 2:51, Mike Kravetz wrote:
> On 4/10/21 12:23 AM, Miaohe Lin wrote:
>> The local variable pseudo_vma is not used anymore.
>>
>> Signed-off-by: Miaohe Lin
>
> Thanks,
>
> That should have been removed with 1b426bac66e6 ("hugetlb: use same f
On 2021/4/12 11:30, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> We will use percpu-refcount to serialize against concurrent swapoff. This
>> patch adds the percpu_ref support for later fixup.
>>
>> Signed-off-by: Miaohe Lin
>> ---
>> include/linux/sw
On 2021/4/12 9:44, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/10 1:17, Tim Chen wrote:
>>>
>>>
>>> On 4/9/21 1:42 AM, Miaohe Lin wrote:
>>>> On 2021/4/9 5:34, Tim Chen wrote:
>>>>>
>>>>>
>>>>
On 2021/4/12 8:55, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/4/9 16:50, Huang, Ying wrote:
>>> Miaohe Lin writes:
>>>
>>>> While we released the pte lock, somebody else might faulted in this pte.
>>>> So we should check
On 2021/3/30 15:27, Yu Zhao wrote:
> On Tue, Mar 30, 2021 at 12:57 AM Huang, Ying wrote:
>>
>> Yu Zhao writes:
>>
>>> On Mon, Mar 29, 2021 at 9:44 PM Huang, Ying wrote:
>>>>
>>>> Miaohe Lin writes:
>>>>
>>>>>
On 2021/4/11 4:02, Yu Zhao wrote:
> On Sat, Apr 10, 2021 at 5:01 AM Miaohe Lin wrote:
>>
>> On 2021/4/10 18:42, Yu Zhao wrote:
>>> On Sat, Apr 10, 2021 at 1:30 AM Miaohe Lin wrote:
>>>>
>>>> Hi:
>>>> On 2021/4/5 18:20, Miaohe Lin wrote:
On 2021/4/10 18:42, Yu Zhao wrote:
> On Sat, Apr 10, 2021 at 1:30 AM Miaohe Lin wrote:
>>
>> Hi:
>> On 2021/4/5 18:20, Miaohe Lin wrote:
>>> frontswap_register_ops can race with swapon. Consider the following scene:
>>
>> Any comment or suggestion? Or
Hi:
On 2021/4/5 18:20, Miaohe Lin wrote:
> frontswap_register_ops can race with swapon. Consider the following scene:
Any comment or suggestion? Or is this race window too theoretical to fix?
Thanks.
>
> CPU1
file. As a result, remove_inode_hugepages will never find any
huge pages associated with the inode and the passed value 'freed' will
always be zero."
Add a comment clarifying this to make it clear and also avoid confusion.
Signed-off-by: Miaohe Lin
---
mm/hugetlb.c | 3 +++
1 file
The same VM_BUG_ON() check is already done in the callee. Remove this extra
one to simplify the code slightly.
Reviewed-by: Mike Kravetz
Signed-off-by: Miaohe Lin
---
mm/hugetlb.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c22111f3da20..a03a50b7c410
these cases.
Fixes: b5cec28d36f5 ("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: Miaohe Lin
---
mm/hugetlb.c | 11 +--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 387c9a62615e..a14bb1a03ee4 10064
ove the HPAGE_RESV_OWNER check per Mike
add a comment to hugetlb_unreserve_pages per Mike
expand warning message a bit for hugetlb_fix_reserve_counts
Add a new patch to remove unused variable
Many thanks for Mike's review and suggestion!
Miaohe Lin (5):
mm/hugeltb: remove redundant VM_BUG
The local variable pseudo_vma is not used anymore.
Signed-off-by: Miaohe Lin
---
fs/hugetlbfs/inode.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index d81f52b87bd7..a2a42335e8fd 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
.
Signed-off-by: Miaohe Lin
---
mm/hugetlb.c | 41 -
1 file changed, 20 insertions(+), 21 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a03a50b7c410..9b4c05699a90 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2163,27 +2163,26 @@ static long
On 2021/4/10 1:17, Tim Chen wrote:
>
>
> On 4/9/21 1:42 AM, Miaohe Lin wrote:
>> On 2021/4/9 5:34, Tim Chen wrote:
>>>
>>>
>>> On 4/8/21 6:08 AM, Miaohe Lin wrote:
>>>> When I was investigating the swap code, I foun
On 2021/4/9 16:50, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> While we released the pte lock, somebody else might faulted in this pte.
>> So we should check whether it's swap pte first to guard against such race
>> or swp_type would be unexpected. And we can als
On 2021/4/9 5:34, Tim Chen wrote:
>
>
> On 4/8/21 6:08 AM, Miaohe Lin wrote:
>> When I was investigating the swap code, I found the below possible race
>> window:
>>
>> CPU 1CPU 2
>> -
On 2021/4/8 22:55, riteshh wrote:
> On 21/04/08 09:08AM, Miaohe Lin wrote:
>> Hi all,
>> When I was investigating the swap code, I found some possible race
>> windows. This series aims to fix all these races. But using current
>> get/put_swap_device() to guard
On 2021/4/9 13:04, Andrew Morton wrote:
> On Fri, 9 Apr 2021 11:17:49 +0800 Miaohe Lin wrote:
>
>> On 2021/4/9 7:25, Mike Kravetz wrote:
>>> On 4/2/21 2:32 AM, Miaohe Lin wrote:
>>>> A rare out of memory error would prevent removal of the r
On 2021/4/9 12:37, Mike Kravetz wrote:
> On 4/8/21 8:01 PM, Miaohe Lin wrote:
>> On 2021/4/9 6:53, Mike Kravetz wrote:
>>>
>>> Yes, add a comment to hugetlb_unreserve_pages saying that !resv_map
>>> implies freed == 0.
>>>
>>
>> Sound
On 2021/4/9 7:25, Mike Kravetz wrote:
> On 4/2/21 2:32 AM, Miaohe Lin wrote:
>> A rare out of memory error would prevent removal of the reserve map region
>> for a page. hugetlb_fix_reserve_counts() handles this rare case to avoid
>> dangling with incorrect
On 2021/4/9 6:53, Mike Kravetz wrote:
> On 4/7/21 8:26 PM, Miaohe Lin wrote:
>> On 2021/4/8 11:24, Miaohe Lin wrote:
>>> On 2021/4/8 4:53, Mike Kravetz wrote:
>>>> On 4/7/21 12:24 AM, Miaohe Lin wrote:
>>>>> Hi:
>>>>> On 2021/4/7 10:
On 2021/4/9 6:40, Mike Kravetz wrote:
> On 4/7/21 7:44 PM, Miaohe Lin wrote:
>> On 2021/4/8 5:23, Mike Kravetz wrote:
>>> On 4/6/21 8:09 PM, Miaohe Lin wrote:
>>>> On 2021/4/7 10:37, Mike Kravetz wrote:
>>>>> On 4/6/21 7:05 PM, Miaohe Lin wrote:
>
The function get_shadow_from_swap_cache() can race with swapoff, though
it's only called by do_swap_page() now.
Fixes: aae466b0052e ("mm/swap: implement workingset detection for anonymous
LRU")
Signed-off-by: Miaohe Lin
---
mm/swap_state.c | 9 ++---
1 file changed, 6 insert
s race window(as suggested by Huang, Ying).
Fixes: 235b62176712 ("mm/swap: add cluster lock")
Signed-off-by: Miaohe Lin
---
include/linux/swap.h | 2 +-
mm/memory.c | 10 ++
mm/swapfile.c| 28 +++-
3 files changed, 22 insertions(+), 18 de
We will use percpu-refcount to serialize against concurrent swapoff. This
patch adds the percpu_ref support for later fixup.
Signed-off-by: Miaohe Lin
---
include/linux/swap.h | 2 ++
mm/swapfile.c| 25 ++---
2 files changed, 24 insertions(+), 3 deletions(-)
diff
swap_cluster_readahead() could race with swapoff and might dereference
si->swap_file after it's released by swapoff. Close this race window by
using get/put_swap_device() pair.
Signed-off-by: Miaohe Lin
---
mm/swap_state.c | 11 +--
1 file changed, 9 insertions(+), 2 deletions(-)
d
swap readahead")
Signed-off-by: Miaohe Lin
---
mm/swap_state.c | 13 +
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 709c260d644a..3bf0d0c297bc 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -724,10 +724,10 @@ s
in the respective changelogs.
Thanks!
Miaohe Lin (5):
mm/swapfile: add percpu_ref support for swap
swap: fix do_swap_page() race with swapoff
mm/swap_state: fix get_shadow_from_swap_cache() race with swapoff
mm/swap_state: fix potential faulted in race in swap_ra_info()
mm/swap_state: fix
On 2021/4/8 11:24, Miaohe Lin wrote:
> On 2021/4/8 4:53, Mike Kravetz wrote:
>> On 4/7/21 12:24 AM, Miaohe Lin wrote:
>>> Hi:
>>> On 2021/4/7 10:49, Mike Kravetz wrote:
>>>> On 4/2/21 2:32 AM, Miaohe Lin wrote:
>>>>> The resv_map could
On 2021/4/8 4:53, Mike Kravetz wrote:
> On 4/7/21 12:24 AM, Miaohe Lin wrote:
>> Hi:
>> On 2021/4/7 10:49, Mike Kravetz wrote:
>>> On 4/2/21 2:32 AM, Miaohe Lin wrote:
>>>> The resv_map could be NULL since this routine can be called in the evict
>>>
On 2021/4/8 5:23, Mike Kravetz wrote:
> On 4/6/21 8:09 PM, Miaohe Lin wrote:
>> On 2021/4/7 10:37, Mike Kravetz wrote:
>>> On 4/6/21 7:05 PM, Miaohe Lin wrote:
>>>> Hi:
>>>> On 2021/4/7 8:53, Mike Kravetz wrote:
>>>>> On 4/2/21 2:32
Hi:
On 2021/4/7 10:49, Mike Kravetz wrote:
> On 4/2/21 2:32 AM, Miaohe Lin wrote:
>> The resv_map could be NULL since this routine can be called in the evict
>> inode path for all hugetlbfs inodes. So we could have chg = 0 and this
>> would result in a negative v
On 2021/4/7 10:37, Mike Kravetz wrote:
> On 4/6/21 7:05 PM, Miaohe Lin wrote:
>> Hi:
>> On 2021/4/7 8:53, Mike Kravetz wrote:
>>> On 4/2/21 2:32 AM, Miaohe Lin wrote:
>>>> It's guaranteed that the vma is associated with a resv_map, i.e. either
>>>>
Hi:
On 2021/4/7 8:53, Mike Kravetz wrote:
> On 4/2/21 2:32 AM, Miaohe Lin wrote:
>> It's guaranteed that the vma is associated with a resv_map, i.e. either
>> VM_MAYSHARE or HPAGE_RESV_OWNER, when the code reaches here or we would
>> have returned via !resv check above. So re
th frontswap
is uninitialized yet. Fix all these by using swapon_mutex to guard against
race with swapon and add swap_info_get_if_under_swapoff() to collect swap
devices under swapoff.
Fixes: d1dc6f1bcf1e ("frontswap: allow multiple backends")
Signed-off-by: Miaohe Lin
---
include/linux/
("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: Miaohe Lin
---
mm/hugetlb.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b7864abded3d..bdff8d23803f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5413
these cases.
Fixes: b5cec28d36f5 ("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: Miaohe Lin
---
mm/hugetlb.c | 11 +--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index bdff8d23803f..ca5464ed04b7 10064
The same VM_BUG_ON() check is already done in the callee. Remove this extra
one to simplify the code slightly.
Signed-off-by: Miaohe Lin
---
mm/hugetlb.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c22111f3da20..a03a50b7c410 100644
--- a/mm/hugetlb.c
It's guaranteed that the vma is associated with a resv_map, i.e. either
VM_MAYSHARE or HPAGE_RESV_OWNER, when the code reaches here or we would
have returned via !resv check above. So ret must be less than 0 in the
'else' case. Simplify the return code to make this clear.
Signed-off-by: Miaohe
Hi all,
This series contains cleanups to remove redundant VM_BUG_ON() and
simplify the return code. Also this fixes potential wrong gbl_reserve
value and handle the error case in hugetlb_fix_reserve_counts(). More
details can be found in the respective changelogs. Thanks!
Miaohe Lin (4):
mm
On 2021/4/1 11:35, Roman Gushchin wrote:
> On Thu, Apr 01, 2021 at 11:31:16AM +0800, Miaohe Lin wrote:
>> On 2021/4/1 11:01, Muchun Song wrote:
>>> Christian Borntraeger reported a warning about "percpu ref
>>> (obj_cgroup_release) <= 0 (-1) after switchin
On 2021/4/1 11:01, Muchun Song wrote:
> Christian Borntraeger reported a warning about "percpu ref
> (obj_cgroup_release) <= 0 (-1) after switching to atomic".
> Because we forgot to obtain the reference to the objcg and
> wrongly obtain the reference of memcg.
>
> Reported-by: Christian
The macro KSM_FLAG_MASK is used in rmap_walk_ksm() only. So we can replace
~KSM_FLAG_MASK with PAGE_MASK to remove this dedicated macro and make code
more consistent because PAGE_MASK is used elsewhere in this file.
Signed-off-by: Miaohe Lin
---
mm/ksm.c | 4 +---
1 file changed, 1 insertion
The same VM_BUG_ON_PAGE() check is already done in the callee. Remove these
extra caller one to simplify code slightly.
Signed-off-by: Miaohe Lin
---
mm/ksm.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/mm/ksm.c b/mm/ksm.c
index 1f2c62e1d797..359afb3023b4 100644
--- a/mm/ksm.c
+++ b/mm
ble_node
return;
We would miss the rmap_item for stable_node and might result in failed
rmap_walk_ksm(). Fix this by set rmap_item->head to NULL when rmap_item
is removed from stable tree.
Fixes: 4146d2d673e8 ("ksm: make !merge_across_nodes migration safe")
Signed-off-by: Miaohe
It's unnecessary to lock the page when get ksm page if we're going to
remove the rmap item as page migration is irrelevant in this case. Use
GET_KSM_PAGE_NOLOCK instead to save some page lock cycles.
Signed-off-by: Miaohe Lin
---
mm/ksm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions
Hi all,
This series contains cleanups to remove unnecessary VM_BUG_ON_PAGE and
dedicated macro KSM_FLAG_MASK. Also this fixes potential missing rmap_item
for stable_node which would result in failed rmap_walk_ksm(). More details
can be found in the respective changelogs. Thanks!
Miaohe Lin (4
On 2021/3/30 11:44, Huang, Ying wrote:
> Miaohe Lin writes:
>
>> On 2021/3/30 9:57, Huang, Ying wrote:
>>> Hi, Miaohe,
>>>
>>> Miaohe Lin writes:
>>>
>>>> Hi all,
>>>> I am investigating the swap
On 2021/3/30 9:57, Huang, Ying wrote:
> Hi, Miaohe,
>
> Miaohe Lin writes:
>
>> Hi all,
>> I am investigating the swap code, and I found the below possible race window:
>>
>> CPU 1
by: Michal Hocko
> Reviewed-by: Muchun Song
Looks good to me. Thanks!
Reviewed-by: Miaohe Lin
> ---
> mm/hugetlb.c | 32 +++-
> 1 file changed, 27 insertions(+), 5 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 16bea
Hi all,
I am investigating the swap code, and I found the below possible race window:
CPU 1 CPU 2
- -
do_swap_page
skip swapcache case (synchronous swap_readpage)
alloc_page_vma
On 2021/3/27 3:57, Mike Kravetz wrote:
> On 3/25/21 7:10 PM, Miaohe Lin wrote:
>> On 2021/3/25 8:28, Mike Kravetz wrote:
>>> The new remove_hugetlb_page() routine is designed to remove a hugetlb
>>> page from hugetlbfs processing. It will remove the page from the acti
On 2021/3/25 8:28, Mike Kravetz wrote:
> After making hugetlb lock irq safe and separating some functionality
> done under the lock, add some lockdep_assert_held to help verify
> locking.
>
Looks good to me. Thanks.
Reviewed-by: Miaohe Lin
> Signed-off-by: Mike Kravetz
> -
s
> + *which operate on the resulting compound page.
It seems HPageFreed and HPageTemporary is cleared. Which hugetlb specific page
flags
is reserverd here and why? Could you please give a simple example to clarify
this in the comment to help understand this NOTE?
The code looks g
; + struct mutex mutex;
I am also with Michal and Oscar here, renaming the mutex to something closer to
its function.
Reviewed-by: Miaohe Lin
> int next_nid_to_alloc;
> int next_nid_to_free;
> unsigned int order;
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
&
Hi:
On 2021/3/25 8:28, Mike Kravetz wrote:
> This effort is the result a recent bug report [1]. In subsequent
> discussions [2], it was deemed necessary to properly fix the hugetlb
Many thanks for the effort. I have read the discussions and it is pretty long.
Maybe it would be helpful if you
Hi all,
This series contains cleanups to remove unnecessary out label and
meaningless !pte_present() check. Also use helper function to simplify
the code. More details can be found in the respective changelogs.
Thanks!
Miaohe Lin (3):
khugepaged: use helper function range_in_vma
We know it must meet the !is_swap_pte() and !pte_none() condition if we
reach here. Since !is_swap_pte() indicates pte_none() or pte_present()
is met, it's guaranteed that pte must be present here.
Signed-off-by: Miaohe Lin
---
mm/khugepaged.c | 4
1 file changed, 4 deletions(-)
diff
The out label here is unneeded because it just goes to out_up_write label.
Remove it to make code more concise.
Signed-off-by: Miaohe Lin
---
mm/khugepaged.c | 8 +++-
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index ad0444f3f487
We could use helper function range_in_vma() to check whether the desired
range is inside the vma to simplify the code.
Signed-off-by: Miaohe Lin
---
mm/khugepaged.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index b81521dfbb1a
The putback_movable_page() is just called by putback_movable_pages() and
we know the page is locked and both PageMovable() and PageIsolated() is
checked right before calling putback_movable_page(). So we make it static
and remove all the 3 VM_BUG_ON_PAGE().
Signed-off-by: Miaohe Lin
---
include
e first
place."
Reviewed-by: Yang Shi
Signed-off-by: Miaohe Lin
---
mm/migrate.c | 18 ++
1 file changed, 2 insertions(+), 16 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index c621c8f6fb7d..51190759e6dd 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -210
It's more recommended to use helper function migrate_vma_collect_skip() to
skip the unexpected case and it also helps remove some duplicated codes.
Move migrate_vma_collect_skip() above migrate_vma_collect_hole() to avoid
compiler warning.
Reviewed-by: David Hildenbrand
Signed-off-by: Miaohe Lin
It's guaranteed that in the 'else' case of the rc == MIGRATEPAGE_SUCCESS
check, rc does not equal to MIGRATEPAGE_SUCCESS. Remove this unnecessary
check.
Reviewed-by: David Hildenbrand
Reviewed-by: Yang Shi
Signed-off-by: Miaohe Lin
---
mm/migrate.c | 2 +-
1 file changed, 1 insertion(+), 1
h CPU")
Signed-off-by: Miaohe Lin
---
mm/migrate.c | 7 +++
1 file changed, 7 insertions(+)
diff --git a/mm/migrate.c b/mm/migrate.c
index dacbdc9710ac..87bbad578127 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2968,6 +2968,13 @@ static void migrate_vma_insert_page(struct migrate_vma
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