After the common decompress part goes to __zswap_load(), we can cleanup
the zswap_load() a little.

Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 mm/zswap.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index 3433bd6b3cef..86886276cb81 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1759,7 +1759,6 @@ bool zswap_load(struct folio *folio)
 	struct zswap_tree *tree = zswap_trees[type];
 	struct zswap_entry *entry;
 	u8 *dst;
-	bool ret;
 
 	VM_WARN_ON_ONCE(!folio_test_locked(folio));
 
@@ -1776,19 +1775,16 @@ bool zswap_load(struct folio *folio)
 		dst = kmap_local_page(page);
 		zswap_fill_page(dst, entry->value);
 		kunmap_local(dst);
-		ret = true;
-		goto stats;
+	} else {
+		__zswap_load(entry, page);
 	}
 
-	__zswap_load(entry, page);
-	ret = true;
-stats:
 	count_vm_event(ZSWPIN);
 	if (entry->objcg)
 		count_objcg_event(entry->objcg, ZSWPIN);
 
 	spin_lock(&tree->lock);
-	if (ret && zswap_exclusive_loads_enabled) {
+	if (zswap_exclusive_loads_enabled) {
 		zswap_invalidate_entry(tree, entry);
 		folio_mark_dirty(folio);
 	} else if (entry->length) {
@@ -1798,7 +1794,7 @@ bool zswap_load(struct folio *folio)
 	zswap_entry_put(tree, entry);
 	spin_unlock(&tree->lock);
 
-	return ret;
+	return true;
 }
 
 void zswap_invalidate(int type, pgoff_t offset)

-- 
b4 0.10.1

On Mon, Dec 18, 2023 at 3:50 AM Chengming Zhou
<zhouchengming@bytedance.com> wrote:
>
> After the common decompress part goes to __zswap_load(), we can cleanup
> the zswap_load() a little.
>
> Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
> ---
>  mm/zswap.c | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 3433bd6b3cef..86886276cb81 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -1759,7 +1759,6 @@ bool zswap_load(struct folio *folio)
>         struct zswap_tree *tree = zswap_trees[type];
>         struct zswap_entry *entry;
>         u8 *dst;
> -       bool ret;
>
>         VM_WARN_ON_ONCE(!folio_test_locked(folio));
>
> @@ -1776,19 +1775,16 @@ bool zswap_load(struct folio *folio)
>                 dst = kmap_local_page(page);
>                 zswap_fill_page(dst, entry->value);
>                 kunmap_local(dst);
> -               ret = true;
> -               goto stats;
> +       } else {
> +               __zswap_load(entry, page);

Very minor nitpick. I think this change you only take out the "ret",
you don't have to remove the goto. Personally I prefer the one with
the goto because If (!entry->length) is a rare case, having them
indented match the normal execution flow is the streamlined one
without indentation.

If you keep the else statement without the goto. You can move
__zswap_load(entry,page) to the if statement so most common case go
through the if statement rather than else.

I also think this commit can fold into the previous one. As I said,
this is minor comment, it is your call.

Acked-by: Chis Li <chrisl@kernel.org> (Google)

Chris

On 2023/12/19 20:47, Chris Li wrote:
> On Mon, Dec 18, 2023 at 3:50 AM Chengming Zhou
> <zhouchengming@bytedance.com> wrote:
>>
>> After the common decompress part goes to __zswap_load(), we can cleanup
>> the zswap_load() a little.
>>
>> Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
>> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
>> ---
>>  mm/zswap.c | 12 ++++--------
>>  1 file changed, 4 insertions(+), 8 deletions(-)
>>
>> diff --git a/mm/zswap.c b/mm/zswap.c
>> index 3433bd6b3cef..86886276cb81 100644
>> --- a/mm/zswap.c
>> +++ b/mm/zswap.c
>> @@ -1759,7 +1759,6 @@ bool zswap_load(struct folio *folio)
>>         struct zswap_tree *tree = zswap_trees[type];
>>         struct zswap_entry *entry;
>>         u8 *dst;
>> -       bool ret;
>>
>>         VM_WARN_ON_ONCE(!folio_test_locked(folio));
>>
>> @@ -1776,19 +1775,16 @@ bool zswap_load(struct folio *folio)
>>                 dst = kmap_local_page(page);
>>                 zswap_fill_page(dst, entry->value);
>>                 kunmap_local(dst);
>> -               ret = true;
>> -               goto stats;
>> +       } else {
>> +               __zswap_load(entry, page);
> 
> Very minor nitpick. I think this change you only take out the "ret",
> you don't have to remove the goto. Personally I prefer the one with
> the goto because If (!entry->length) is a rare case, having them
> indented match the normal execution flow is the streamlined one
> without indentation.
> 
> If you keep the else statement without the goto. You can move
> __zswap_load(entry,page) to the if statement so most common case go
> through the if statement rather than else.

Make sense. I will change if a new version is needed.

> 
> I also think this commit can fold into the previous one. As I said,
> this is minor comment, it is your call.
> 
> Acked-by: Chis Li <chrisl@kernel.org> (Google)

Thanks for review!