[PATCH] MM: cleanup on addition to bootmem data list

[PATCH] MM: cleanup on addition to bootmem data list

[Gavin Shan]

The objects of "struct bootmem_data_t" are being linked together
to form double-linked list sequentially based on its minimal page
frame number. Current implementation implicitly supports the
following cases, which means the inserting point for current bootmem
data depends on how "list_for_each" works. That makes the code a
little hard to read. Besides, "list_for_each" and "list_entry" can
be replaced with "list_for_each_entry".

        - The linked list is empty.
        - There has no entry in the linked list, whose minimal page
          frame number is bigger than current one.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
 mm/bootmem.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 0131170..5a04536 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -77,16 +77,16 @@ unsigned long __init bootmem_bootmap_pages(unsigned long pages)
  */
 static void __init link_bootmem(bootmem_data_t *bdata)
 {
-	struct list_head *iter;
+	bootmem_data_t *ent;
 
-	list_for_each(iter, &bdata_list) {
-		bootmem_data_t *ent;
-
-		ent = list_entry(iter, bootmem_data_t, list);
-		if (bdata->node_min_pfn < ent->node_min_pfn)
-			break;
+	list_for_each_entry(ent, &bdata_list, list) {
+		if (bdata->node_min_pfn < ent->node_min_pfn) {
+			list_add_tail(&bdata->list, &ent->list);
+			return;
+		}
 	}
-	list_add_tail(&bdata->list, iter);
+
+	list_add_tail(&bdata->list, &bdata_list);
 }
 
 /*
-- 
1.7.5.4

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Re: [PATCH] MM: cleanup on addition to bootmem data list

[Gavin Shan]

Hi Andrew,

Not sure you got chance to having quick look on this?

Thanks,
Gavin

>The objects of "struct bootmem_data_t" are being linked together
>to form double-linked list sequentially based on its minimal page
>frame number. Current implementation implicitly supports the
>following cases, which means the inserting point for current bootmem
>data depends on how "list_for_each" works. That makes the code a
>little hard to read. Besides, "list_for_each" and "list_entry" can
>be replaced with "list_for_each_entry".
>
>        - The linked list is empty.
>        - There has no entry in the linked list, whose minimal page
>          frame number is bigger than current one.
>
>Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
>Acked-by: Johannes Weiner <hannes@cmpxchg.org>
>---
> mm/bootmem.c |   16 ++++++++--------
> 1 files changed, 8 insertions(+), 8 deletions(-)
>
>diff --git a/mm/bootmem.c b/mm/bootmem.c
>index 0131170..5a04536 100644
>--- a/mm/bootmem.c
>+++ b/mm/bootmem.c
>@@ -77,16 +77,16 @@ unsigned long __init bootmem_bootmap_pages(unsigned long pages)
>  */
> static void __init link_bootmem(bootmem_data_t *bdata)
> {
>-	struct list_head *iter;
>+	bootmem_data_t *ent;
>
>-	list_for_each(iter, &bdata_list) {
>-		bootmem_data_t *ent;
>-
>-		ent = list_entry(iter, bootmem_data_t, list);
>-		if (bdata->node_min_pfn < ent->node_min_pfn)
>-			break;
>+	list_for_each_entry(ent, &bdata_list, list) {
>+		if (bdata->node_min_pfn < ent->node_min_pfn) {
>+			list_add_tail(&bdata->list, &ent->list);
>+			return;
>+		}
> 	}
>-	list_add_tail(&bdata->list, iter);
>+
>+	list_add_tail(&bdata->list, &bdata_list);
> }
>
> /*
>-- 
>1.7.5.4
>

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