* [PATCH v5 1/6] ksm: abstract the function try_to_get_old_rmap_item
@ 2022-12-30 1:12 yang.yang29
2023-01-18 14:03 ` David Hildenbrand
0 siblings, 1 reply; 4+ messages in thread
From: yang.yang29 @ 2022-12-30 1:12 UTC (permalink / raw)
To: akpm
Cc: david, imbrenda, jiang.xuexin, linux-kernel, linux-mm,
ran.xiaokai, xu.xin.sc, xu.xin16, yang.yang29
From: xu xin <xu.xin16@zte.com.cn>
A new function try_to_get_old_rmap_item is abstracted from
get_next_rmap_item. This function will be reused by the subsequent
patches about counting ksm_zero_pages.
The patch improves the readability and reusability of KSM code.
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Cc: David Hildenbrand <david@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn>
Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
---
mm/ksm.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/mm/ksm.c b/mm/ksm.c
index 83e2f74ae7da..5b0a7343ff4a 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2214,23 +2214,36 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite
}
}
-static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot,
- struct ksm_rmap_item **rmap_list,
- unsigned long addr)
+static struct ksm_rmap_item *try_to_get_old_rmap_item(unsigned long addr,
+ struct ksm_rmap_item **rmap_list)
{
- struct ksm_rmap_item *rmap_item;
-
while (*rmap_list) {
- rmap_item = *rmap_list;
+ struct ksm_rmap_item *rmap_item = *rmap_list;
if ((rmap_item->address & PAGE_MASK) == addr)
return rmap_item;
if (rmap_item->address > addr)
break;
*rmap_list = rmap_item->rmap_list;
+ /* Running here indicates it's vma has been UNMERGEABLE */
remove_rmap_item_from_tree(rmap_item);
free_rmap_item(rmap_item);
}
+ return NULL;
+}
+
+static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot,
+ struct ksm_rmap_item **rmap_list,
+ unsigned long addr)
+{
+ struct ksm_rmap_item *rmap_item;
+
+ /* lookup if we have a old rmap_item matching the addr*/
+ rmap_item = try_to_get_old_rmap_item(addr, rmap_list);
+ if (rmap_item)
+ return rmap_item;
+
+ /* Need to allocate a new rmap_item */
rmap_item = alloc_rmap_item();
if (rmap_item) {
/* It has already been zeroed */
--
2.15.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v5 1/6] ksm: abstract the function try_to_get_old_rmap_item
2022-12-30 1:12 [PATCH v5 1/6] ksm: abstract the function try_to_get_old_rmap_item yang.yang29
@ 2023-01-18 14:03 ` David Hildenbrand
2023-02-04 6:43 ` yang.yang29
0 siblings, 1 reply; 4+ messages in thread
From: David Hildenbrand @ 2023-01-18 14:03 UTC (permalink / raw)
To: yang.yang29, akpm
Cc: imbrenda, jiang.xuexin, linux-kernel, linux-mm, ran.xiaokai,
xu.xin.sc, xu.xin16
On 30.12.22 02:12, yang.yang29@zte.com.cn wrote:
> From: xu xin <xu.xin16@zte.com.cn>
>
> A new function try_to_get_old_rmap_item is abstracted from
> get_next_rmap_item. This function will be reused by the subsequent
> patches about counting ksm_zero_pages.
>
> The patch improves the readability and reusability of KSM code.
>
> Signed-off-by: xu xin <xu.xin16@zte.com.cn>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
> Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
> Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn>
> Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
> ---
> mm/ksm.c | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/mm/ksm.c b/mm/ksm.c
> index 83e2f74ae7da..5b0a7343ff4a 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -2214,23 +2214,36 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite
> }
> }
>
> -static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot,
> - struct ksm_rmap_item **rmap_list,
> - unsigned long addr)
> +static struct ksm_rmap_item *try_to_get_old_rmap_item(unsigned long addr,
> + struct ksm_rmap_item **rmap_list)
> {
> - struct ksm_rmap_item *rmap_item;
> -
> while (*rmap_list) {
> - rmap_item = *rmap_list;
> + struct ksm_rmap_item *rmap_item = *rmap_list;
Empty line missing.
> if ((rmap_item->address & PAGE_MASK) == addr)
> return rmap_item;
> if (rmap_item->address > addr)
> break;
> *rmap_list = rmap_item->rmap_list;
> + /* Running here indicates it's vma has been UNMERGEABLE */
"If we end up here, the VMA is UNMERGEABLE."
Although I am not sure if that is true?
> remove_rmap_item_from_tree(rmap_item);
> free_rmap_item(rmap_item);
> }
>
> + return NULL;
> +}
> +
> +static struct ksm_rmap_item *get_next_rmap_item(struct ksm_mm_slot *mm_slot,
> + struct ksm_rmap_item **rmap_list,
> + unsigned long addr)
> +{
> + struct ksm_rmap_item *rmap_item;
> +
> + /* lookup if we have a old rmap_item matching the addr*/
I suggest dropping that comment, "try_to_get_old_rmap_item()" is
expressive enough.
> + rmap_item = try_to_get_old_rmap_item(addr, rmap_list);
> + if (rmap_item)
> + return rmap_item;
> +
> + /* Need to allocate a new rmap_item */
I suggest dropping that comment for the same reason.
> rmap_item = alloc_rmap_item();
> if (rmap_item) {
> /* It has already been zeroed */
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v5 1/6] ksm: abstract the function try_to_get_old_rmap_item
2023-01-18 14:03 ` David Hildenbrand
@ 2023-02-04 6:43 ` yang.yang29
2023-02-13 12:51 ` David Hildenbrand
0 siblings, 1 reply; 4+ messages in thread
From: yang.yang29 @ 2023-02-04 6:43 UTC (permalink / raw)
To: david
Cc: akpm, imbrenda, jiang.xuexin, linux-kernel, linux-mm,
ran.xiaokai, xu.xin.sc, xu.xin16
Thanks for these suggestions, we will take them into patch v6.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v5 1/6] ksm: abstract the function try_to_get_old_rmap_item
2023-02-04 6:43 ` yang.yang29
@ 2023-02-13 12:51 ` David Hildenbrand
0 siblings, 0 replies; 4+ messages in thread
From: David Hildenbrand @ 2023-02-13 12:51 UTC (permalink / raw)
To: yang.yang29
Cc: akpm, imbrenda, jiang.xuexin, linux-kernel, linux-mm,
ran.xiaokai, xu.xin.sc, xu.xin16
On 04.02.23 07:43, yang.yang29@zte.com.cn wrote:
> Thanks for these suggestions, we will take them into patch v6.
Please don't remove all context from your replies. Makes it really hard
to follow-up :)
Further, there seems to be an issue with threading and your mails. For
example, your cover letter [1] does not link the other patches like [2],
for example, because the patches don't have "in-reply-to:" tags. Try
using "git send-email", that should take care of threading automatically.
[1] https://lore.kernel.org/all/202302100915227721315@zte.com.cn/
[2] https://lore.kernel.org/all/202302100916423431376@zte.com.cn/
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-02-13 12:52 UTC | newest]
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2022-12-30 1:12 [PATCH v5 1/6] ksm: abstract the function try_to_get_old_rmap_item yang.yang29
2023-01-18 14:03 ` David Hildenbrand
2023-02-04 6:43 ` yang.yang29
2023-02-13 12:51 ` David Hildenbrand
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