2020-09-06 06:55:18

by Souptick Joarder

[permalink] [raw]
Subject: [PATCH 2/2] xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*()

In 2019, we introduced pin_user_pages*() and now we are converting
get_user_pages*() to the new API as appropriate. [1] & [2] could
be referred for more information. This is case 5 as per document [1].

[1] Documentation/core-api/pin_user_pages.rst

[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/

Signed-off-by: Souptick Joarder <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: David Vrabel <[email protected]>
---
drivers/xen/gntdev.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 5e1411b..a36b712 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -731,7 +731,7 @@ static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt,
unsigned long xen_pfn;
int ret;

- ret = get_user_pages_fast(addr, 1, batch->writeable ? FOLL_WRITE : 0, &page);
+ ret = pin_user_pages_fast(addr, 1, batch->writeable ? FOLL_WRITE : 0, &page);
if (ret < 0)
return ret;

@@ -745,13 +745,7 @@ static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt,

static void gntdev_put_pages(struct gntdev_copy_batch *batch)
{
- unsigned int i;
-
- for (i = 0; i < batch->nr_pages; i++) {
- if(batch->writeable && !PageDirty(batch->pages[i]))
- set_page_dirty_lock(batch->pages[i]);
- put_page(batch->pages[i]);
- }
+ unpin_user_pages_dirty_lock(batch->pages, batch->nr_pages, batch->writeable);
batch->nr_pages = 0;
batch->writeable = false;
}
--
1.9.1


2020-09-11 16:58:21

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH 2/2] xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*()


On 9/6/20 2:51 AM, Souptick Joarder wrote:
> In 2019, we introduced pin_user_pages*() and now we are converting
> get_user_pages*() to the new API as appropriate. [1] & [2] could
> be referred for more information. This is case 5 as per document [1].
>
> [1] Documentation/core-api/pin_user_pages.rst
>
> [2] "Explicit pinning of user-space pages":
> https://lwn.net/Articles/807108/
>
> Signed-off-by: Souptick Joarder <[email protected]>
> Cc: John Hubbard <[email protected]>
> Cc: Boris Ostrovsky <[email protected]>
> Cc: Juergen Gross <[email protected]>
> Cc: David Vrabel <[email protected]>


Reviewed-by: Boris Ostrovsky <[email protected]>


2020-09-29 12:11:19

by Souptick Joarder

[permalink] [raw]
Subject: Re: [PATCH 2/2] xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*()

On Fri, Sep 11, 2020 at 8:12 PM <[email protected]> wrote:
>
>
> On 9/6/20 2:51 AM, Souptick Joarder wrote:
> > In 2019, we introduced pin_user_pages*() and now we are converting
> > get_user_pages*() to the new API as appropriate. [1] & [2] could
> > be referred for more information. This is case 5 as per document [1].
> >
> > [1] Documentation/core-api/pin_user_pages.rst
> >
> > [2] "Explicit pinning of user-space pages":
> > https://lwn.net/Articles/807108/
> >
> > Signed-off-by: Souptick Joarder <[email protected]>
> > Cc: John Hubbard <[email protected]>
> > Cc: Boris Ostrovsky <[email protected]>
> > Cc: Juergen Gross <[email protected]>
> > Cc: David Vrabel <[email protected]>
>
>
> Reviewed-by: Boris Ostrovsky <[email protected]>

Are these 2 patches queued for 5.10-rc1 ?
>
>

2020-09-29 12:32:52

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH 2/2] xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*()


On 9/29/20 8:09 AM, Souptick Joarder wrote:
> On Fri, Sep 11, 2020 at 8:12 PM <[email protected]> wrote:
>>
>> On 9/6/20 2:51 AM, Souptick Joarder wrote:
>>> In 2019, we introduced pin_user_pages*() and now we are converting
>>> get_user_pages*() to the new API as appropriate. [1] & [2] could
>>> be referred for more information. This is case 5 as per document [1].
>>>
>>> [1] Documentation/core-api/pin_user_pages.rst
>>>
>>> [2] "Explicit pinning of user-space pages":
>>> https://lwn.net/Articles/807108/
>>>
>>> Signed-off-by: Souptick Joarder <[email protected]>
>>> Cc: John Hubbard <[email protected]>
>>> Cc: Boris Ostrovsky <[email protected]>
>>> Cc: Juergen Gross <[email protected]>
>>> Cc: David Vrabel <[email protected]>
>>
>> Reviewed-by: Boris Ostrovsky <[email protected]>
> Are these 2 patches queued for 5.10-rc1 ?


Yes, I am preparing the branch. (BTW, your second patch appears to have been either manually edited or not generated on top of the first patch. Please don't do this next time)


-boris

2020-09-30 02:15:59

by Souptick Joarder

[permalink] [raw]
Subject: Re: [PATCH 2/2] xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*()

On Tue, Sep 29, 2020 at 6:00 PM <[email protected]> wrote:
>
>
> On 9/29/20 8:09 AM, Souptick Joarder wrote:
> > On Fri, Sep 11, 2020 at 8:12 PM <[email protected]> wrote:
> >>
> >> On 9/6/20 2:51 AM, Souptick Joarder wrote:
> >>> In 2019, we introduced pin_user_pages*() and now we are converting
> >>> get_user_pages*() to the new API as appropriate. [1] & [2] could
> >>> be referred for more information. This is case 5 as per document [1].
> >>>
> >>> [1] Documentation/core-api/pin_user_pages.rst
> >>>
> >>> [2] "Explicit pinning of user-space pages":
> >>> https://lwn.net/Articles/807108/
> >>>
> >>> Signed-off-by: Souptick Joarder <[email protected]>
> >>> Cc: John Hubbard <[email protected]>
> >>> Cc: Boris Ostrovsky <[email protected]>
> >>> Cc: Juergen Gross <[email protected]>
> >>> Cc: David Vrabel <[email protected]>
> >>
> >> Reviewed-by: Boris Ostrovsky <[email protected]>
> > Are these 2 patches queued for 5.10-rc1 ?
>
>
> Yes, I am preparing the branch. (BTW, your second patch appears to have been either manually edited or not generated on top of the first patch. Please don't do this next time)

I created it on top of the first one and didn't edit manually.
I was able to apply it in my local repository.
What was the error ?

2020-09-30 14:12:36

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH 2/2] xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*()



On 9/29/20 10:14 PM, Souptick Joarder wrote:
> On Tue, Sep 29, 2020 at 6:00 PM <[email protected]> wrote:
>>
>>
>> On 9/29/20 8:09 AM, Souptick Joarder wrote:
>>> On Fri, Sep 11, 2020 at 8:12 PM <[email protected]> wrote:
>>>>
>>>> On 9/6/20 2:51 AM, Souptick Joarder wrote:
>>>>> In 2019, we introduced pin_user_pages*() and now we are converting
>>>>> get_user_pages*() to the new API as appropriate. [1] & [2] could
>>>>> be referred for more information. This is case 5 as per document [1].
>>>>>
>>>>> [1] Documentation/core-api/pin_user_pages.rst
>>>>>
>>>>> [2] "Explicit pinning of user-space pages":
>>>>> https://lwn.net/Articles/807108/
>>>>>
>>>>> Signed-off-by: Souptick Joarder <[email protected]>
>>>>> Cc: John Hubbard <[email protected]>
>>>>> Cc: Boris Ostrovsky <[email protected]>
>>>>> Cc: Juergen Gross <[email protected]>
>>>>> Cc: David Vrabel <[email protected]>
>>>>
>>>> Reviewed-by: Boris Ostrovsky <[email protected]>
>>> Are these 2 patches queued for 5.10-rc1 ?
>>
>>
>> Yes, I am preparing the branch. (BTW, your second patch appears to have been either manually edited or not generated on top of the first patch. Please don't do this next time)
>
> I created it on top of the first one and didn't edit manually.
> I was able to apply it in my local repository.
> What was the error ?
>


Patch 1:

+ if (batch->writeable && !PageDirty(batch->pages[i]))


Patch 2:

- if(batch->writeable && !PageDirty(batch->pages[i]))



This doesn't look to me like usual whitespace damage in-flight. Anyway, this has been applied to for-linus-5.10


-boris