Remove unneeded PageLRU(p) and is_free_buddy_page(p) check as slab caches
are not shrunk now. This check can be added back when a lightweight range
based shrinker is available.
Signed-off-by: Miaohe Lin <[email protected]>
---
mm/memory-failure.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 5b663eca1f29..92f951df3e87 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -373,11 +373,10 @@ void shake_page(struct page *p)
if (PageHuge(p))
return;
- if (!PageSlab(p)) {
- lru_add_drain_all();
- if (PageLRU(p) || is_free_buddy_page(p))
- return;
- }
+ if (PageSlab(p))
+ return;
+
+ lru_add_drain_all();
/*
* TODO: Could shrink slab caches here if a lightweight range-based
--
2.27.0
On Sun, Jun 25, 2023 at 07:34:30PM +0800, Miaohe Lin wrote:
> Remove unneeded PageLRU(p) and is_free_buddy_page(p) check as slab caches
> are not shrunk now. This check can be added back when a lightweight range
> based shrinker is available.
I think your logic is faulty. Based on the reasoning above, this patch
should be:
> - if (!PageSlab(p)) {
> - lru_add_drain_all();
> - if (PageLRU(p) || is_free_buddy_page(p))
> - return;
> - }
> + if (PageSlab(p))
> + return;
> +
> + lru_add_drain_all();
+ if (PageLRU(p) || is_free_buddy_page(p))
+ return;
but maybe it's the description that is wrong.
On Sun, Jun 25, 2023 at 07:34:30PM +0800, Miaohe Lin wrote:
> Remove unneeded PageLRU(p) and is_free_buddy_page(p) check as slab caches
> are not shrunk now. This check can be added back when a lightweight range
> based shrinker is available.
On further review, I think you've misunderstood the entire situation
here and no patch should be applied.
> Signed-off-by: Miaohe Lin <[email protected]>
> ---
> mm/memory-failure.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5b663eca1f29..92f951df3e87 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -373,11 +373,10 @@ void shake_page(struct page *p)
> if (PageHuge(p))
> return;
>
> - if (!PageSlab(p)) {
> - lru_add_drain_all();
> - if (PageLRU(p) || is_free_buddy_page(p))
> - return;
> - }
> + if (PageSlab(p))
> + return;
> +
> + lru_add_drain_all();
>
> /*
> * TODO: Could shrink slab caches here if a lightweight range-based
> --
> 2.27.0
>
>
On Sun, Jun 25, 2023 at 07:34:30PM +0800, Miaohe Lin wrote:
> Remove unneeded PageLRU(p) and is_free_buddy_page(p) check as slab caches
> are not shrunk now. This check can be added back when a lightweight range
> based shrinker is available.
>
> Signed-off-by: Miaohe Lin <[email protected]>
This looks to me a good cleanup because the result of
"if (PageLRU(p) || is_free_buddy_page(p))" check is not used, so the check
itself is unneeded.
> ---
> mm/memory-failure.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5b663eca1f29..92f951df3e87 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -373,11 +373,10 @@ void shake_page(struct page *p)
> if (PageHuge(p))
> return;
>
> - if (!PageSlab(p)) {
> - lru_add_drain_all();
> - if (PageLRU(p) || is_free_buddy_page(p))
> - return;
> - }
> + if (PageSlab(p))
> + return;
> +
> + lru_add_drain_all();
>
> /*
> * TODO: Could shrink slab caches here if a lightweight range-based
I think that this TODO comment can be put together with "if (PageSlab)" block.
Thanks,
Naoya Horiguchi
On 2023/6/26 8:52, Naoya Horiguchi wrote:
> On Sun, Jun 25, 2023 at 07:34:30PM +0800, Miaohe Lin wrote:
>> Remove unneeded PageLRU(p) and is_free_buddy_page(p) check as slab caches
>> are not shrunk now. This check can be added back when a lightweight range
>> based shrinker is available.
>>
>> Signed-off-by: Miaohe Lin <[email protected]>
>
> This looks to me a good cleanup because the result of
> "if (PageLRU(p) || is_free_buddy_page(p))" check is not used, so the check
> itself is unneeded.
>
>> ---
>> mm/memory-failure.c | 9 ++++-----
>> 1 file changed, 4 insertions(+), 5 deletions(-)
>>
>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>> index 5b663eca1f29..92f951df3e87 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -373,11 +373,10 @@ void shake_page(struct page *p)
>> if (PageHuge(p))
>> return;
>>
>> - if (!PageSlab(p)) {
>> - lru_add_drain_all();
>> - if (PageLRU(p) || is_free_buddy_page(p))
>> - return;
>> - }
>> + if (PageSlab(p))
>> + return;
>> +
>> + lru_add_drain_all();
>>
>> /*
>> * TODO: Could shrink slab caches here if a lightweight range-based
>
> I think that this TODO comment can be put together with "if (PageSlab)" block.
Thanks for your comment and advice. Do you mean something like below?
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 5b663eca1f29..66e7b3ceaf2d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -372,17 +372,14 @@ void shake_page(struct page *p)
{
if (PageHuge(p))
return;
-
- if (!PageSlab(p)) {
- lru_add_drain_all();
- if (PageLRU(p) || is_free_buddy_page(p))
- return;
- }
-
/*
* TODO: Could shrink slab caches here if a lightweight range-based
* shrinker will be available.
*/
+ if (PageSlab(p))
+ return;
+
+ lru_add_drain_all();
}
EXPORT_SYMBOL_GPL(shake_page);
Thanks.
On 2023/6/26 3:50, Matthew Wilcox wrote:
> On Sun, Jun 25, 2023 at 07:34:30PM +0800, Miaohe Lin wrote:
>> Remove unneeded PageLRU(p) and is_free_buddy_page(p) check as slab caches
>> are not shrunk now. This check can be added back when a lightweight range
>> based shrinker is available.
>
> On further review, I think you've misunderstood the entire situation
> here and no patch should be applied.
Thanks for your review. I think you might misunderstood the patch. What I want
to do here is remove the unneeded if block:
if (PageLRU(p) || is_free_buddy_page(p))
return;
Because nothing is done after the check. So this check is useless and should be removed.
Thanks.
On Mon, Jun 26, 2023 at 09:43:44AM +0800, Miaohe Lin wrote:
> On 2023/6/26 8:52, Naoya Horiguchi wrote:
> > On Sun, Jun 25, 2023 at 07:34:30PM +0800, Miaohe Lin wrote:
> >> Remove unneeded PageLRU(p) and is_free_buddy_page(p) check as slab caches
> >> are not shrunk now. This check can be added back when a lightweight range
> >> based shrinker is available.
> >>
> >> Signed-off-by: Miaohe Lin <[email protected]>
> >
> > This looks to me a good cleanup because the result of
> > "if (PageLRU(p) || is_free_buddy_page(p))" check is not used, so the check
> > itself is unneeded.
> >
> >> ---
> >> mm/memory-failure.c | 9 ++++-----
> >> 1 file changed, 4 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> >> index 5b663eca1f29..92f951df3e87 100644
> >> --- a/mm/memory-failure.c
> >> +++ b/mm/memory-failure.c
> >> @@ -373,11 +373,10 @@ void shake_page(struct page *p)
> >> if (PageHuge(p))
> >> return;
> >>
> >> - if (!PageSlab(p)) {
> >> - lru_add_drain_all();
> >> - if (PageLRU(p) || is_free_buddy_page(p))
> >> - return;
> >> - }
> >> + if (PageSlab(p))
> >> + return;
> >> +
> >> + lru_add_drain_all();
> >>
> >> /*
> >> * TODO: Could shrink slab caches here if a lightweight range-based
> >
> > I think that this TODO comment can be put together with "if (PageSlab)" block.
>
> Thanks for your comment and advice. Do you mean something like below?
Yes, this is what I mean. Feel free to add my ack when posting v2.
Acked-by: Naoya Horiguchi <[email protected]>
Thank you.
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5b663eca1f29..66e7b3ceaf2d 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -372,17 +372,14 @@ void shake_page(struct page *p)
> {
> if (PageHuge(p))
> return;
> -
> - if (!PageSlab(p)) {
> - lru_add_drain_all();
> - if (PageLRU(p) || is_free_buddy_page(p))
> - return;
> - }
> -
> /*
> * TODO: Could shrink slab caches here if a lightweight range-based
> * shrinker will be available.
> */
> + if (PageSlab(p))
> + return;
> +
> + lru_add_drain_all();
> }
> EXPORT_SYMBOL_GPL(shake_page);
>
> Thanks.
>
>