From: Mika Penttilä <[email protected]>
Migrating file pages and swapcache pages into device memory is not supported.
The decision is done based on page_mapping(). For now, swapcache pages are not migrated.
Things can however be improved, for swapcache pages. Try to get rid of the swap cache,
and if successful, go ahead as with other anonymous pages.
Cc: Alistair Popple <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Ralph Campbell <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Reviewed-by: "Huang, Ying" <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
Signed-off-by: Mika Penttilä <[email protected]>
---
v3:
- Adjust comments
- Add Reviewed-bys
v2:
- use folio_test_anon() (Huang, Ying)
mm/migrate_device.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index d30c9de60b0d..f76ebccfe067 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -747,13 +747,23 @@ static void __migrate_device_pages(unsigned long *src_pfns,
if (is_device_private_page(newpage) ||
is_device_coherent_page(newpage)) {
- /*
- * For now only support anonymous memory migrating to
- * device private or coherent memory.
- */
+
if (mapping) {
- src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
- continue;
+ struct folio *folio;
+
+ folio = page_folio(page);
+
+ /*
+ * For now only support anonymous memory migrating to
+ * device private or coherent memory.
+ *
+ * Try to get rid of swap cache if possible.
+ *
+ */
+ if (!folio_test_anon(folio) || !folio_free_swap(folio)) {
+ src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
+ continue;
+ }
}
} else if (is_zone_device_page(newpage)) {
/*
--
2.17.1
On 06.06.23 09:44, David Hildenbrand wrote:
> On 06.06.23 07:01, [email protected] wrote:
>> From: Mika Penttilä <[email protected]>
>>
>> Migrating file pages and swapcache pages into device memory is not supported.
>> The decision is done based on page_mapping(). For now, swapcache pages are not migrated.
>>
>> Things can however be improved, for swapcache pages. Try to get rid of the swap cache,
>> and if successful, go ahead as with other anonymous pages.
>>
>> Cc: Alistair Popple <[email protected]>
>> Cc: John Hubbard <[email protected]>
>> Cc: Ralph Campbell <[email protected]>
>> Cc: "Huang, Ying" <[email protected]>
>> Reviewed-by: "Huang, Ying" <[email protected]>
>> Reviewed-by: Alistair Popple <[email protected]>
>> Signed-off-by: Mika Penttilä <[email protected]>
>> ---
>>
>> v3:
>> - Adjust comments
>> - Add Reviewed-bys
>>
>> v2:
>> - use folio_test_anon() (Huang, Ying)
>>
>> mm/migrate_device.c | 22 ++++++++++++++++------
>> 1 file changed, 16 insertions(+), 6 deletions(-)
>>
>> diff --git a/mm/migrate_device.c b/mm/migrate_device.c
>> index d30c9de60b0d..f76ebccfe067 100644
>> --- a/mm/migrate_device.c
>> +++ b/mm/migrate_device.c
>> @@ -747,13 +747,23 @@ static void __migrate_device_pages(unsigned long *src_pfns,
>>
>> if (is_device_private_page(newpage) ||
>> is_device_coherent_page(newpage)) {
>> - /*
>> - * For now only support anonymous memory migrating to
>> - * device private or coherent memory.
>> - */
>> +
>> if (mapping) {
>> - src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
>> - continue;
>> + struct folio *folio;
>> +
>> + folio = page_folio(page);
>> +
>> + /*
>> + * For now only support anonymous memory migrating to
>> + * device private or coherent memory.
>> + *
>> + * Try to get rid of swap cache if possible.
>> + *
>> + */
>> + if (!folio_test_anon(folio) || !folio_free_swap(folio)) {
>> + src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
>> + continue;
>
> I'm pretty sure the folio has to be locked in order to call
> folio_free_swap().
>
Oh, staring at the bigger context, I assume we locked the folios via
migrate_device_range(), correct?
--
Cheers,
David / dhildenb
On 06.06.23 07:01, [email protected] wrote:
> From: Mika Penttilä <[email protected]>
>
> Migrating file pages and swapcache pages into device memory is not supported.
> The decision is done based on page_mapping(). For now, swapcache pages are not migrated.
>
> Things can however be improved, for swapcache pages. Try to get rid of the swap cache,
> and if successful, go ahead as with other anonymous pages.
>
> Cc: Alistair Popple <[email protected]>
> Cc: John Hubbard <[email protected]>
> Cc: Ralph Campbell <[email protected]>
> Cc: "Huang, Ying" <[email protected]>
> Reviewed-by: "Huang, Ying" <[email protected]>
> Reviewed-by: Alistair Popple <[email protected]>
> Signed-off-by: Mika Penttilä <[email protected]>
> ---
>
> v3:
> - Adjust comments
> - Add Reviewed-bys
>
> v2:
> - use folio_test_anon() (Huang, Ying)
>
> mm/migrate_device.c | 22 ++++++++++++++++------
> 1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/mm/migrate_device.c b/mm/migrate_device.c
> index d30c9de60b0d..f76ebccfe067 100644
> --- a/mm/migrate_device.c
> +++ b/mm/migrate_device.c
> @@ -747,13 +747,23 @@ static void __migrate_device_pages(unsigned long *src_pfns,
>
> if (is_device_private_page(newpage) ||
> is_device_coherent_page(newpage)) {
> - /*
> - * For now only support anonymous memory migrating to
> - * device private or coherent memory.
> - */
> +
> if (mapping) {
> - src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
> - continue;
> + struct folio *folio;
> +
> + folio = page_folio(page);
> +
> + /*
> + * For now only support anonymous memory migrating to
> + * device private or coherent memory.
> + *
> + * Try to get rid of swap cache if possible.
> + *
> + */
> + if (!folio_test_anon(folio) || !folio_free_swap(folio)) {
> + src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
> + continue;
I'm pretty sure the folio has to be locked in order to call
folio_free_swap().
--
Cheers,
David / dhildenb
Hi,
On 6.6.2023 10.46, David Hildenbrand wrote:
> On 06.06.23 09:44, David Hildenbrand wrote:
>> On 06.06.23 07:01, [email protected] wrote:
>>> From: Mika Penttilä <[email protected]>
>>>
>>> Migrating file pages and swapcache pages into device memory is not
>>> supported.
>>> The decision is done based on page_mapping(). For now, swapcache
>>> pages are not migrated.
>>>
>>> Things can however be improved, for swapcache pages. Try to get rid
>>> of the swap cache,
>>> and if successful, go ahead as with other anonymous pages.
>>>
>>> Cc: Alistair Popple <[email protected]>
>>> Cc: John Hubbard <[email protected]>
>>> Cc: Ralph Campbell <[email protected]>
>>> Cc: "Huang, Ying" <[email protected]>
>>> Reviewed-by: "Huang, Ying" <[email protected]>
>>> Reviewed-by: Alistair Popple <[email protected]>
>>> Signed-off-by: Mika Penttilä <[email protected]>
>>> ---
>>>
>>> v3:
>>> - Adjust comments
>>> - Add Reviewed-bys
>>>
>>> v2:
>>> - use folio_test_anon() (Huang, Ying)
>>>
>>> mm/migrate_device.c | 22 ++++++++++++++++------
>>> 1 file changed, 16 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/mm/migrate_device.c b/mm/migrate_device.c
>>> index d30c9de60b0d..f76ebccfe067 100644
>>> --- a/mm/migrate_device.c
>>> +++ b/mm/migrate_device.c
>>> @@ -747,13 +747,23 @@ static void __migrate_device_pages(unsigned
>>> long *src_pfns,
>>> if (is_device_private_page(newpage) ||
>>> is_device_coherent_page(newpage)) {
>>> - /*
>>> - * For now only support anonymous memory migrating to
>>> - * device private or coherent memory.
>>> - */
>>> +
>>> if (mapping) {
>>> - src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
>>> - continue;
>>> + struct folio *folio;
>>> +
>>> + folio = page_folio(page);
>>> +
>>> + /*
>>> + * For now only support anonymous memory migrating to
>>> + * device private or coherent memory.
>>> + *
>>> + * Try to get rid of swap cache if possible.
>>> + *
>>> + */
>>> + if (!folio_test_anon(folio) ||
>>> !folio_free_swap(folio)) {
>>> + src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
>>> + continue;
>>
>> I'm pretty sure the folio has to be locked in order to call
>> folio_free_swap().
>>
>
> Oh, staring at the bigger context, I assume we locked the folios via
> migrate_device_range(), correct?
>
Yes either that, or when migrating via virtual addresses
migrate_vma_collect_pmd() has trylock_page() and we migrate only pages
which succeed locking.
--Mika
On Tue, Jun 06, 2023 at 08:01:49AM +0300, [email protected] wrote:
> From: Mika Penttil? <[email protected]>
>
> Migrating file pages and swapcache pages into device memory is not supported.
> The decision is done based on page_mapping(). For now, swapcache pages are not migrated.
Please fix the commit log formatting, it should not exceed 7 lines.
> if (is_device_private_page(newpage) ||
> is_device_coherent_page(newpage)) {
> - /*
> - * For now only support anonymous memory migrating to
> - * device private or coherent memory.
> - */
> +
> if (mapping) {
Very nitpicky, but this empty line looks odd. Also isn't the comment
still (mostly) correct given that file backed memory is still not
supported?
> + /*
> + * For now only support anonymous memory migrating to
> + * device private or coherent memory.
> + *
> + * Try to get rid of swap cache if possible.
> + *
> + */
> + if (!folio_test_anon(folio) || !folio_free_swap(folio)) {
Please avoid the overly long lines.
Hi,
On 7.6.2023 17.10, Christoph Hellwig wrote:
> On Tue, Jun 06, 2023 at 08:01:49AM +0300, [email protected] wrote:
>> From: Mika Penttilä <[email protected]>
>>
>> Migrating file pages and swapcache pages into device memory is not supported.
>> The decision is done based on page_mapping(). For now, swapcache pages are not migrated.
>
> Please fix the commit log formatting, it should not exceed 7 lines.
>
>> if (is_device_private_page(newpage) ||
>> is_device_coherent_page(newpage)) {
>> - /*
>> - * For now only support anonymous memory migrating to
>> - * device private or coherent memory.
>> - */
>> +
>> if (mapping) {
>
> Very nitpicky, but this empty line looks odd. Also isn't the comment
> still (mostly) correct given that file backed memory is still not
> supported?
Yes the comment is mostly correct and moved a few lines lower,
complemented with a comment about the swap cache.
>
>> + /*
>> + * For now only support anonymous memory migrating to
>> + * device private or coherent memory.
>> + *
>> + * Try to get rid of swap cache if possible.
>> + *
>> + */
>> + if (!folio_test_anon(folio) || !folio_free_swap(folio)) {
>
> Please avoid the overly long lines.
>
Thanks,
Mika
On 7.6.2023 17.10, Christoph Hellwig wrote:
> On Tue, Jun 06, 2023 at 08:01:49AM +0300, [email protected] wrote:
>> From: Mika Penttilä <[email protected]>
>>
>> Migrating file pages and swapcache pages into device memory is not supported.
>> The decision is done based on page_mapping(). For now, swapcache pages are not migrated.
>
> Please fix the commit log formatting, it should not exceed 7 lines.
Not sure what you mean should not exceed 7 lines..?
On Wed, Jun 07, 2023 at 07:06:06PM +0300, Mika Penttil? wrote:
>
>
> On 7.6.2023 17.10, Christoph Hellwig wrote:
> > On Tue, Jun 06, 2023 at 08:01:49AM +0300, [email protected] wrote:
> > > From: Mika Penttil? <[email protected]>
> > >
> > > Migrating file pages and swapcache pages into device memory is not supported.
> > > The decision is done based on page_mapping(). For now, swapcache pages are not migrated.
> >
> > Please fix the commit log formatting, it should not exceed 7 lines.
>
> Not sure what you mean should not exceed 7 lines..?
Sorry, this should be 73.