* [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
@ 2024-03-06 15:52 Zi Yan
2024-03-13 11:23 ` Charan Teja Kalla
2024-03-30 9:20 ` Patch "mm/migrate: set swap entry values of THP tail pages properly." has been added to the 6.1-stable tree gregkh
0 siblings, 2 replies; 13+ messages in thread
From: Zi Yan @ 2024-03-06 15:52 UTC (permalink / raw)
To: gregkh, stable
Cc: Zi Yan, linux-mm, Charan Teja Kalla, Matthew Wilcox (Oracle),
David Hildenbrand, Andrew Morton, Huang Ying, Naoya Horiguchi
From: Zi Yan <ziy@nvidia.com>
The tail pages in a THP can have swap entry information stored in their
private field. When migrating to a new page, all tail pages of the new
page need to update ->private to avoid future data corruption.
This fix is stable-only, since after commit 07e09c483cbe ("mm/huge_memory:
work on folio->swap instead of page->private when splitting folio"),
subpages of a swapcached THP no longer requires the maintenance.
Adding THPs to the swapcache was introduced in commit
38d8b4e6bdc87 ("mm, THP, swap: delay splitting THP during swap out"),
where each subpage of a THP added to the swapcache had its own swapcache
entry and required the ->private field to point to the correct swapcache
entry. Later, when THP migration functionality was implemented in commit
616b8371539a6 ("mm: thp: enable thp migration in generic path"),
it initially did not handle the subpages of swapcached THPs, failing to
update their ->private fields or replace the subpage pointers in the
swapcache. Subsequently, commit e71769ae5260 ("mm: enable thp migration
for shmem thp") addressed the swapcache update aspect. This patch fixes
the update of subpage ->private fields.
Closes: https://lore.kernel.org/linux-mm/1707814102-22682-1-git-send-email-quic_charante@quicinc.com/
Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
---
mm/migrate.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index c93dd6a31c31..c5968021fde0 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -423,8 +423,12 @@ int folio_migrate_mapping(struct address_space *mapping,
if (folio_test_swapbacked(folio)) {
__folio_set_swapbacked(newfolio);
if (folio_test_swapcache(folio)) {
+ int i;
+
folio_set_swapcache(newfolio);
- newfolio->private = folio_get_private(folio);
+ for (i = 0; i < nr; i++)
+ set_page_private(folio_page(newfolio, i),
+ page_private(folio_page(folio, i)));
}
entries = nr;
} else {
--
2.43.0
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-06 15:52 [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly Zi Yan
@ 2024-03-13 11:23 ` Charan Teja Kalla
2024-03-30 9:20 ` Patch "mm/migrate: set swap entry values of THP tail pages properly." has been added to the 6.1-stable tree gregkh
1 sibling, 0 replies; 13+ messages in thread
From: Charan Teja Kalla @ 2024-03-13 11:23 UTC (permalink / raw)
To: Zi Yan, gregkh, stable
Cc: linux-mm, Matthew Wilcox (Oracle),
David Hildenbrand, Andrew Morton, Huang Ying, Naoya Horiguchi
On 3/6/2024 9:22 PM, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
>
> The tail pages in a THP can have swap entry information stored in their
> private field. When migrating to a new page, all tail pages of the new
> page need to update ->private to avoid future data corruption.
>
> This fix is stable-only, since after commit 07e09c483cbe ("mm/huge_memory:
> work on folio->swap instead of page->private when splitting folio"),
> subpages of a swapcached THP no longer requires the maintenance.
>
> Adding THPs to the swapcache was introduced in commit
> 38d8b4e6bdc87 ("mm, THP, swap: delay splitting THP during swap out"),
> where each subpage of a THP added to the swapcache had its own swapcache
> entry and required the ->private field to point to the correct swapcache
> entry. Later, when THP migration functionality was implemented in commit
> 616b8371539a6 ("mm: thp: enable thp migration in generic path"),
> it initially did not handle the subpages of swapcached THPs, failing to
> update their ->private fields or replace the subpage pointers in the
> swapcache. Subsequently, commit e71769ae5260 ("mm: enable thp migration
> for shmem thp") addressed the swapcache update aspect. This patch fixes
> the update of subpage ->private fields.
>
> Closes: https://lore.kernel.org/linux-mm/1707814102-22682-1-git-send-email-quic_charante@quicinc.com/
> Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> Acked-by: David Hildenbrand <david@redhat.com>
Tested this patch for 6.1 kernel and observed no issues. With that,
Reported-and-tested-by: Charan Teja Kalla <quic_charante@quicinc.com>
Thanks,
Charan
^ permalink raw reply [flat|nested] 13+ messages in thread
* Patch "mm/migrate: set swap entry values of THP tail pages properly." has been added to the 6.1-stable tree
2024-03-06 15:52 [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly Zi Yan
2024-03-13 11:23 ` Charan Teja Kalla
@ 2024-03-30 9:20 ` gregkh
1 sibling, 0 replies; 13+ messages in thread
From: gregkh @ 2024-03-30 9:20 UTC (permalink / raw)
To: 1707814102-22682-1-git-send-email-quic_charante, akpm, david,
gregkh, linux-mm, naoya.horiguchi, quic_charante, willy,
ying.huang, zi.yan, ziy
Cc: stable-commits
This is a note to let you know that I've just added the patch titled
mm/migrate: set swap entry values of THP tail pages properly.
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-migrate-set-swap-entry-values-of-thp-tail-pages-properly.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
From stable+bounces-27001-greg=kroah.com@vger.kernel.org Wed Mar 6 16:52:30 2024
From: Zi Yan <zi.yan@sent.com>
Date: Wed, 6 Mar 2024 10:52:17 -0500
Subject: mm/migrate: set swap entry values of THP tail pages properly.
To: gregkh@linuxfoundation.org, stable@vger.kernel.org
Cc: Zi Yan <ziy@nvidia.com>, linux-mm@kvack.org, Charan Teja Kalla <quic_charante@quicinc.com>, "Matthew Wilcox (Oracle)" <willy@infradead.org>, David Hildenbrand <david@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Huang Ying <ying.huang@intel.com>, Naoya Horiguchi <naoya.horiguchi@linux.dev>
Message-ID: <20240306155217.118467-1-zi.yan@sent.com>
From: Zi Yan <ziy@nvidia.com>
The tail pages in a THP can have swap entry information stored in their
private field. When migrating to a new page, all tail pages of the new
page need to update ->private to avoid future data corruption.
This fix is stable-only, since after commit 07e09c483cbe ("mm/huge_memory:
work on folio->swap instead of page->private when splitting folio"),
subpages of a swapcached THP no longer requires the maintenance.
Adding THPs to the swapcache was introduced in commit
38d8b4e6bdc87 ("mm, THP, swap: delay splitting THP during swap out"),
where each subpage of a THP added to the swapcache had its own swapcache
entry and required the ->private field to point to the correct swapcache
entry. Later, when THP migration functionality was implemented in commit
616b8371539a6 ("mm: thp: enable thp migration in generic path"),
it initially did not handle the subpages of swapcached THPs, failing to
update their ->private fields or replace the subpage pointers in the
swapcache. Subsequently, commit e71769ae5260 ("mm: enable thp migration
for shmem thp") addressed the swapcache update aspect. This patch fixes
the update of subpage ->private fields.
Closes: https://lore.kernel.org/linux-mm/1707814102-22682-1-git-send-email-quic_charante@quicinc.com/
Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reported-and-tested-by: Charan Teja Kalla <quic_charante@quicinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
mm/migrate.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -423,8 +423,12 @@ int folio_migrate_mapping(struct address
if (folio_test_swapbacked(folio)) {
__folio_set_swapbacked(newfolio);
if (folio_test_swapcache(folio)) {
+ int i;
+
folio_set_swapcache(newfolio);
- newfolio->private = folio_get_private(folio);
+ for (i = 0; i < nr; i++)
+ set_page_private(folio_page(newfolio, i),
+ page_private(folio_page(folio, i)));
}
entries = nr;
} else {
Patches currently in stable-queue which might be from kroah.com@vger.kernel.org are
queue-6.1/vfio-pci-create-persistent-intx-handler.patch
queue-6.1/vfio-fsl-mc-block-calling-interrupt-handler-without-trigger.patch
queue-6.1/vfio-pci-disable-auto-enable-of-exclusive-intx-irq.patch
queue-6.1/vfio-introduce-interface-to-flush-virqfd-inject-workqueue.patch
queue-6.1/mm-migrate-set-swap-entry-values-of-thp-tail-pages-properly.patch
queue-6.1/vfio-platform-create-persistent-irq-handlers.patch
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
@ 2024-03-05 16:13 Zi Yan
2024-03-05 16:17 ` Zi Yan
` (2 more replies)
0 siblings, 3 replies; 13+ messages in thread
From: Zi Yan @ 2024-03-05 16:13 UTC (permalink / raw)
To: gregkh, stable
Cc: Zi Yan, linux-mm, Charan Teja Kalla, Matthew Wilcox (Oracle),
David Hildenbrand, Andrew Morton, Huang Ying, Naoya Horiguchi
From: Zi Yan <ziy@nvidia.com>
The tail pages in a THP can have swap entry information stored in their
private field. When migrating to a new page, all tail pages of the new
page need to update ->private to avoid future data corruption.
Signed-off-by: Zi Yan <ziy@nvidia.com>
---
mm/migrate.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index c93dd6a31c31..c5968021fde0 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -423,8 +423,12 @@ int folio_migrate_mapping(struct address_space *mapping,
if (folio_test_swapbacked(folio)) {
__folio_set_swapbacked(newfolio);
if (folio_test_swapcache(folio)) {
+ int i;
+
folio_set_swapcache(newfolio);
- newfolio->private = folio_get_private(folio);
+ for (i = 0; i < nr; i++)
+ set_page_private(folio_page(newfolio, i),
+ page_private(folio_page(folio, i)));
}
entries = nr;
} else {
--
2.43.0
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 16:13 [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly Zi Yan
@ 2024-03-05 16:17 ` Zi Yan
2024-03-05 16:22 ` Charan Teja Kalla
2024-03-05 16:22 ` David Hildenbrand
2024-03-05 22:04 ` Greg KH
2 siblings, 1 reply; 13+ messages in thread
From: Zi Yan @ 2024-03-05 16:17 UTC (permalink / raw)
To: gregkh, stable
Cc: Zi Yan, linux-mm, Charan Teja Kalla,
"Matthew Wilcox (Oracle)",
David Hildenbrand, Andrew Morton, Huang Ying, Naoya Horiguchi
[-- Attachment #1: Type: text/plain, Size: 1305 bytes --]
On 5 Mar 2024, at 11:13, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
>
> The tail pages in a THP can have swap entry information stored in their
> private field. When migrating to a new page, all tail pages of the new
> page need to update ->private to avoid future data corruption.
Corresponding swapcache entries need to be updated as well.
e71769ae5260 ("mm: enable thp migration for shmem thp") fixed it already.
Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
>
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---
> mm/migrate.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index c93dd6a31c31..c5968021fde0 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -423,8 +423,12 @@ int folio_migrate_mapping(struct address_space *mapping,
> if (folio_test_swapbacked(folio)) {
> __folio_set_swapbacked(newfolio);
> if (folio_test_swapcache(folio)) {
> + int i;
> +
> folio_set_swapcache(newfolio);
> - newfolio->private = folio_get_private(folio);
> + for (i = 0; i < nr; i++)
> + set_page_private(folio_page(newfolio, i),
> + page_private(folio_page(folio, i)));
> }
> entries = nr;
> } else {
> --
> 2.43.0
--
Best Regards,
Yan, Zi
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 16:17 ` Zi Yan
@ 2024-03-05 16:22 ` Charan Teja Kalla
2024-03-05 16:26 ` Zi Yan
0 siblings, 1 reply; 13+ messages in thread
From: Charan Teja Kalla @ 2024-03-05 16:22 UTC (permalink / raw)
To: Zi Yan, gregkh, stable
Cc: linux-mm, Matthew Wilcox (Oracle),
David Hildenbrand, Andrew Morton, Huang Ying, Naoya Horiguchi
Thanks David for various inputs on this patch!!.
On 3/5/2024 9:47 PM, Zi Yan wrote:
> On 5 Mar 2024, at 11:13, Zi Yan wrote:
>
>> From: Zi Yan <ziy@nvidia.com>
>>
>> The tail pages in a THP can have swap entry information stored in their
>> private field. When migrating to a new page, all tail pages of the new
>> page need to update ->private to avoid future data corruption.
>
> Corresponding swapcache entries need to be updated as well.
> e71769ae5260 ("mm: enable thp migration for shmem thp") fixed it already.
>
> Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
>
Thanks Zi Yan, for posting this patch. I think below tag too applicable?
Closes:
https://lore.kernel.org/linux-mm/1707814102-22682-1-git-send-email-quic_charante@quicinc.com/
>
>>
>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>> ---
>> mm/migrate.c | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/migrate.c b/mm/migrate.c
>> index c93dd6a31c31..c5968021fde0 100644
>> --- a/mm/migrate.c
>> +++ b/mm/migrate.c
>> @@ -423,8 +423,12 @@ int folio_migrate_mapping(struct address_space *mapping,
>> if (folio_test_swapbacked(folio)) {
>> __folio_set_swapbacked(newfolio);
>> if (folio_test_swapcache(folio)) {
>> + int i;
>> +
>> folio_set_swapcache(newfolio);
>> - newfolio->private = folio_get_private(folio);
>> + for (i = 0; i < nr; i++)
>> + set_page_private(folio_page(newfolio, i),
>> + page_private(folio_page(folio, i)));
>> }
>> entries = nr;
>> } else {
>> --
>> 2.43.0
>
>
> --
> Best Regards,
> Yan, Zi
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 16:22 ` Charan Teja Kalla
@ 2024-03-05 16:26 ` Zi Yan
0 siblings, 0 replies; 13+ messages in thread
From: Zi Yan @ 2024-03-05 16:26 UTC (permalink / raw)
To: Charan Teja Kalla, gregkh
Cc: stable, linux-mm, "Matthew Wilcox (Oracle)",
David Hildenbrand, Andrew Morton, Huang Ying, Naoya Horiguchi
[-- Attachment #1: Type: text/plain, Size: 1976 bytes --]
On 5 Mar 2024, at 11:22, Charan Teja Kalla wrote:
> Thanks David for various inputs on this patch!!.
>
> On 3/5/2024 9:47 PM, Zi Yan wrote:
>> On 5 Mar 2024, at 11:13, Zi Yan wrote:
>>
>>> From: Zi Yan <ziy@nvidia.com>
>>>
>>> The tail pages in a THP can have swap entry information stored in their
>>> private field. When migrating to a new page, all tail pages of the new
>>> page need to update ->private to avoid future data corruption.
>>
>> Corresponding swapcache entries need to be updated as well.
>> e71769ae5260 ("mm: enable thp migration for shmem thp") fixed it already.
>>
>> Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
>>
>
> Thanks Zi Yan, for posting this patch. I think below tag too applicable?
>
> Closes:
> https://lore.kernel.org/linux-mm/1707814102-22682-1-git-send-email-quic_charante@quicinc.com/
Right. Let me add it to other stable fixes I am going to send.
Hi Greg,
Could you add the information above (text, Fixes, and Closes) to this patch?
Or do you want me to resend?
Thanks.
>
>>
>>>
>>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>>> ---
>>> mm/migrate.c | 6 +++++-
>>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/mm/migrate.c b/mm/migrate.c
>>> index c93dd6a31c31..c5968021fde0 100644
>>> --- a/mm/migrate.c
>>> +++ b/mm/migrate.c
>>> @@ -423,8 +423,12 @@ int folio_migrate_mapping(struct address_space *mapping,
>>> if (folio_test_swapbacked(folio)) {
>>> __folio_set_swapbacked(newfolio);
>>> if (folio_test_swapcache(folio)) {
>>> + int i;
>>> +
>>> folio_set_swapcache(newfolio);
>>> - newfolio->private = folio_get_private(folio);
>>> + for (i = 0; i < nr; i++)
>>> + set_page_private(folio_page(newfolio, i),
>>> + page_private(folio_page(folio, i)));
>>> }
>>> entries = nr;
>>> } else {
>>> --
>>> 2.43.0
>>
>>
>> --
>> Best Regards,
>> Yan, Zi
--
Best Regards,
Yan, Zi
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 16:13 [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly Zi Yan
2024-03-05 16:17 ` Zi Yan
@ 2024-03-05 16:22 ` David Hildenbrand
2024-03-05 22:04 ` Greg KH
2 siblings, 0 replies; 13+ messages in thread
From: David Hildenbrand @ 2024-03-05 16:22 UTC (permalink / raw)
To: Zi Yan, gregkh, stable
Cc: linux-mm, Charan Teja Kalla, Matthew Wilcox (Oracle),
Andrew Morton, Huang Ying, Naoya Horiguchi
On 05.03.24 17:13, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
>
> The tail pages in a THP can have swap entry information stored in their
> private field. When migrating to a new page, all tail pages of the new
> page need to update ->private to avoid future data corruption.
>
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---
> mm/migrate.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index c93dd6a31c31..c5968021fde0 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -423,8 +423,12 @@ int folio_migrate_mapping(struct address_space *mapping,
> if (folio_test_swapbacked(folio)) {
> __folio_set_swapbacked(newfolio);
> if (folio_test_swapcache(folio)) {
> + int i;
> +
> folio_set_swapcache(newfolio);
> - newfolio->private = folio_get_private(folio);
> + for (i = 0; i < nr; i++)
> + set_page_private(folio_page(newfolio, i),
> + page_private(folio_page(folio, i)));
> }
> entries = nr;
> } else {
Hopefully Charan can run the reproducer against this.
Acked-by: David Hildenbrand <david@redhat.com>
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 16:13 [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly Zi Yan
2024-03-05 16:17 ` Zi Yan
2024-03-05 16:22 ` David Hildenbrand
@ 2024-03-05 22:04 ` Greg KH
2024-03-05 22:09 ` David Hildenbrand
2 siblings, 1 reply; 13+ messages in thread
From: Greg KH @ 2024-03-05 22:04 UTC (permalink / raw)
To: Zi Yan
Cc: stable, linux-mm, Charan Teja Kalla, Matthew Wilcox (Oracle),
David Hildenbrand, Andrew Morton, Huang Ying, Naoya Horiguchi
On Tue, Mar 05, 2024 at 11:13:13AM -0500, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
>
> The tail pages in a THP can have swap entry information stored in their
> private field. When migrating to a new page, all tail pages of the new
> page need to update ->private to avoid future data corruption.
>
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---
> mm/migrate.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
What is the git commit id of this change in Linus's tree?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 22:04 ` Greg KH
@ 2024-03-05 22:09 ` David Hildenbrand
2024-03-05 22:32 ` Greg KH
0 siblings, 1 reply; 13+ messages in thread
From: David Hildenbrand @ 2024-03-05 22:09 UTC (permalink / raw)
To: Greg KH, Zi Yan
Cc: stable, linux-mm, Charan Teja Kalla, Matthew Wilcox (Oracle),
Andrew Morton, Huang Ying, Naoya Horiguchi
On 05.03.24 23:04, Greg KH wrote:
> On Tue, Mar 05, 2024 at 11:13:13AM -0500, Zi Yan wrote:
>> From: Zi Yan <ziy@nvidia.com>
>>
>> The tail pages in a THP can have swap entry information stored in their
>> private field. When migrating to a new page, all tail pages of the new
>> page need to update ->private to avoid future data corruption.
>>
>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>> ---
>> mm/migrate.c | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> What is the git commit id of this change in Linus's tree?
Unfortunately, we had to do stable-only versions, because the backport
of the "accidental" fix that removes the per-subpage "private"
information would be non-trivial, especially for pre-folio-converison times.
The accidental fix is
07e09c483cbef2a252f75d95670755a0607288f5
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 22:09 ` David Hildenbrand
@ 2024-03-05 22:32 ` Greg KH
2024-03-05 23:13 ` Zi Yan
0 siblings, 1 reply; 13+ messages in thread
From: Greg KH @ 2024-03-05 22:32 UTC (permalink / raw)
To: David Hildenbrand
Cc: Zi Yan, stable, linux-mm, Charan Teja Kalla,
Matthew Wilcox (Oracle),
Andrew Morton, Huang Ying, Naoya Horiguchi
On Tue, Mar 05, 2024 at 11:09:17PM +0100, David Hildenbrand wrote:
> On 05.03.24 23:04, Greg KH wrote:
> > On Tue, Mar 05, 2024 at 11:13:13AM -0500, Zi Yan wrote:
> > > From: Zi Yan <ziy@nvidia.com>
> > >
> > > The tail pages in a THP can have swap entry information stored in their
> > > private field. When migrating to a new page, all tail pages of the new
> > > page need to update ->private to avoid future data corruption.
> > >
> > > Signed-off-by: Zi Yan <ziy@nvidia.com>
> > > ---
> > > mm/migrate.c | 6 +++++-
> > > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > What is the git commit id of this change in Linus's tree?
>
> Unfortunately, we had to do stable-only versions, because the backport
> of the "accidental" fix that removes the per-subpage "private" information
> would be non-trivial, especially for pre-folio-converison times.
>
> The accidental fix is
>
> 07e09c483cbef2a252f75d95670755a0607288f5
None of that is obvious at all here, we need loads of documentation in
the changelog text that says all of that please.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 22:32 ` Greg KH
@ 2024-03-05 23:13 ` Zi Yan
2024-03-06 13:51 ` Greg KH
0 siblings, 1 reply; 13+ messages in thread
From: Zi Yan @ 2024-03-05 23:13 UTC (permalink / raw)
To: Greg KH
Cc: David Hildenbrand, stable, linux-mm, Charan Teja Kalla,
"Matthew Wilcox (Oracle)",
Andrew Morton, Huang Ying, Naoya Horiguchi
[-- Attachment #1: Type: text/plain, Size: 1932 bytes --]
On 5 Mar 2024, at 17:32, Greg KH wrote:
> On Tue, Mar 05, 2024 at 11:09:17PM +0100, David Hildenbrand wrote:
>> On 05.03.24 23:04, Greg KH wrote:
>>> On Tue, Mar 05, 2024 at 11:13:13AM -0500, Zi Yan wrote:
>>>> From: Zi Yan <ziy@nvidia.com>
>>>>
>>>> The tail pages in a THP can have swap entry information stored in their
>>>> private field. When migrating to a new page, all tail pages of the new
>>>> page need to update ->private to avoid future data corruption.
>>>>
>>>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>>>> ---
>>>> mm/migrate.c | 6 +++++-
>>>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>>
>>> What is the git commit id of this change in Linus's tree?
>>
>> Unfortunately, we had to do stable-only versions, because the backport
>> of the "accidental" fix that removes the per-subpage "private" information
>> would be non-trivial, especially for pre-folio-converison times.
>>
>> The accidental fix is
>>
>> 07e09c483cbef2a252f75d95670755a0607288f5
>
> None of that is obvious at all here, we need loads of documentation in
> the changelog text that says all of that please.
How about?
Before 07e09c483cbe ("mm/huge_memory: work on folio->swap instead of
page->private when splitting folio"), when a THP is added into swapcache,
each of its subpages has its own swapcache entry and need ->private pointing
to the right swapcache entry. THP added to swapcache function is added in
38d8b4e6bdc87 ("mm, THP, swap: delay splitting THP during swap out").
When THP migration was added in 616b8371539a6 ("mm: thp: enable thp migration in generic path"), it did not take care of swapcached THP's subpages,
neither updated subpage's ->private nor replaced subpage pointer in
the swapcache. Later, e71769ae5260 ("mm: enable thp migration for shmem thp")
fixed swapcache update part. Now this patch fixes the subpage ->private
update part.
--
Best Regards,
Yan, Zi
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly.
2024-03-05 23:13 ` Zi Yan
@ 2024-03-06 13:51 ` Greg KH
0 siblings, 0 replies; 13+ messages in thread
From: Greg KH @ 2024-03-06 13:51 UTC (permalink / raw)
To: Zi Yan
Cc: David Hildenbrand, stable, linux-mm, Charan Teja Kalla,
"Matthew Wilcox (Oracle)",
Andrew Morton, Huang Ying, Naoya Horiguchi
On Tue, Mar 05, 2024 at 06:13:39PM -0500, Zi Yan wrote:
> On 5 Mar 2024, at 17:32, Greg KH wrote:
>
> > On Tue, Mar 05, 2024 at 11:09:17PM +0100, David Hildenbrand wrote:
> >> On 05.03.24 23:04, Greg KH wrote:
> >>> On Tue, Mar 05, 2024 at 11:13:13AM -0500, Zi Yan wrote:
> >>>> From: Zi Yan <ziy@nvidia.com>
> >>>>
> >>>> The tail pages in a THP can have swap entry information stored in their
> >>>> private field. When migrating to a new page, all tail pages of the new
> >>>> page need to update ->private to avoid future data corruption.
> >>>>
> >>>> Signed-off-by: Zi Yan <ziy@nvidia.com>
> >>>> ---
> >>>> mm/migrate.c | 6 +++++-
> >>>> 1 file changed, 5 insertions(+), 1 deletion(-)
> >>>
> >>> What is the git commit id of this change in Linus's tree?
> >>
> >> Unfortunately, we had to do stable-only versions, because the backport
> >> of the "accidental" fix that removes the per-subpage "private" information
> >> would be non-trivial, especially for pre-folio-converison times.
> >>
> >> The accidental fix is
> >>
> >> 07e09c483cbef2a252f75d95670755a0607288f5
> >
> > None of that is obvious at all here, we need loads of documentation in
> > the changelog text that says all of that please.
>
> How about?
>
> Before 07e09c483cbe ("mm/huge_memory: work on folio->swap instead of
> page->private when splitting folio"), when a THP is added into swapcache,
> each of its subpages has its own swapcache entry and need ->private pointing
> to the right swapcache entry. THP added to swapcache function is added in
> 38d8b4e6bdc87 ("mm, THP, swap: delay splitting THP during swap out").
> When THP migration was added in 616b8371539a6 ("mm: thp: enable thp migration in generic path"), it did not take care of swapcached THP's subpages,
> neither updated subpage's ->private nor replaced subpage pointer in
> the swapcache. Later, e71769ae5260 ("mm: enable thp migration for shmem thp")
> fixed swapcache update part. Now this patch fixes the subpage ->private
> update part.
That's better than what is there now :)
So yes, please resend all of these with the new text and then we can
queue them up.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2024-03-30 9:20 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-03-06 15:52 [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly Zi Yan
2024-03-13 11:23 ` Charan Teja Kalla
2024-03-30 9:20 ` Patch "mm/migrate: set swap entry values of THP tail pages properly." has been added to the 6.1-stable tree gregkh
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2024-03-05 16:13 [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly Zi Yan
2024-03-05 16:17 ` Zi Yan
2024-03-05 16:22 ` Charan Teja Kalla
2024-03-05 16:26 ` Zi Yan
2024-03-05 16:22 ` David Hildenbrand
2024-03-05 22:04 ` Greg KH
2024-03-05 22:09 ` David Hildenbrand
2024-03-05 22:32 ` Greg KH
2024-03-05 23:13 ` Zi Yan
2024-03-06 13:51 ` Greg KH
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