Re: [PATCH 1/4] mm, page_owner: make init_pages_in_zone() faster

[Vlastimil Babka]

On 08/23/2017 08:47 AM, Vlastimil Babka wrote:
> On 07/24/2017 02:38 PM, Michal Hocko wrote:
>>
>> Do we need to duplicated a part of __set_page_owner? Can we pull out
>> both owner and handle out __set_page_owner?
> 
> I wanted to avoid overhead in __set_page_owner() by introducing extra
> shared function, but I'll check if that can be helped.

Ok, here's a -fix for that.

----8<----
>From b607d021d52c5f4b64874a7e738a62e3f0e5ddea Mon Sep 17 00:00:00 2001
From: Vlastimil Babka <vba...@suse.cz>
Date: Thu, 24 Aug 2017 08:39:58 +0200
Subject: [PATCH] mm, page_owner: make init_pages_in_zone() faster-fix

Don't duplicate code of __set_page_owner(), per Michal Hocko.
---
 mm/page_owner.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 5aa21ca237d9..cd72a74d41a0 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -165,17 +165,13 @@ static noinline depot_stack_handle_t save_stack(gfp_t 
flags)
        return handle;
 }
 
-noinline void __set_page_owner(struct page *page, unsigned int order,
-                                       gfp_t gfp_mask)
+static inline void __set_page_owner_handle(struct page_ext *page_ext,
+       depot_stack_handle_t handle, unsigned int order, gfp_t gfp_mask)
 {
-       struct page_ext *page_ext = lookup_page_ext(page);
        struct page_owner *page_owner;
 
-       if (unlikely(!page_ext))
-               return;
-
        page_owner = get_page_owner(page_ext);
-       page_owner->handle = save_stack(gfp_mask);
+       page_owner->handle = handle;
        page_owner->order = order;
        page_owner->gfp_mask = gfp_mask;
        page_owner->last_migrate_reason = -1;
@@ -183,18 +179,17 @@ noinline void __set_page_owner(struct page *page, 
unsigned int order,
        __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
 }
 
-static void __set_page_owner_init(struct page_ext *page_ext,
-                                       depot_stack_handle_t handle)
+noinline void __set_page_owner(struct page *page, unsigned int order,
+                                       gfp_t gfp_mask)
 {
-       struct page_owner *page_owner;
+       struct page_ext *page_ext = lookup_page_ext(page);
+       depot_stack_handle_t handle;
 
-       page_owner = get_page_owner(page_ext);
-       page_owner->handle = handle;
-       page_owner->order = 0;
-       page_owner->gfp_mask = 0;
-       page_owner->last_migrate_reason = -1;
+       if (unlikely(!page_ext))
+               return;
 
-       __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
+       handle = save_stack(gfp_mask);
+       __set_page_owner_handle(page_ext, handle, order, gfp_mask);
 }
 
 void __set_page_owner_migrate_reason(struct page *page, int reason)
@@ -582,12 +577,12 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct 
zone *zone)
                        if (unlikely(!page_ext))
                                continue;
 
-                       /* Maybe overraping zone */
+                       /* Maybe overlaping zone */
                        if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
                                continue;
 
                        /* Found early allocated page */
-                       __set_page_owner_init(page_ext, init_handle);
+                       __set_page_owner_handle(page_ext, init_handle, 0, 0);
                        count++;
                }
        }
-- 
2.14.1