[PATCH] drm/ttm: swap consecutive allocated pooled pages v4

[PATCH] drm/ttm: swap consecutive allocated pooled pages v4

[Christian König]

When we detect consecutive allocation of pages swap them to avoid
accidentally freeing them as huge page.

v2: use swap
v3: check if it's really the first allocated page
v4: don't touch the loop variable

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/ttm/ttm_page_alloc.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index b6f7ce286fb1..44343a2bf55c 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -958,8 +958,15 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
 	r = ttm_page_pool_get_pages(pool, &plist, flags, cstate,
 				    npages - count, 0);
 
-	list_for_each_entry(p, &plist, lru)
-		pages[count++] = p;
+	first = count;
+	list_for_each_entry(p, &plist, lru) {
+		struct page *tmp = p;
+
+		/* Swap the pages if we detect consecutive order */
+		if (count > first && pages[count - 1] == tmp - 1)
+			swap(tmp, pages[count - 1]);
+		pages[count++] = tmp;
+	}
 
 	if (r) {
 		/* If there is any pages in the list put them back to
-- 
2.11.0

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Re: [PATCH] drm/ttm: swap consecutive allocated pooled pages v4

[Michel Dänzer]

On 2017-12-05 01:54 PM, Christian König wrote:
> When we detect consecutive allocation of pages swap them to avoid
> accidentally freeing them as huge page.
> 
> v2: use swap
> v3: check if it's really the first allocated page
> v4: don't touch the loop variable
> 
> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
>  drivers/gpu/drm/ttm/ttm_page_alloc.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> index b6f7ce286fb1..44343a2bf55c 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> @@ -958,8 +958,15 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
>  	r = ttm_page_pool_get_pages(pool, &plist, flags, cstate,
>  				    npages - count, 0);
>  
> -	list_for_each_entry(p, &plist, lru)
> -		pages[count++] = p;
> +	first = count;
> +	list_for_each_entry(p, &plist, lru) {
> +		struct page *tmp = p;
> +
> +		/* Swap the pages if we detect consecutive order */
> +		if (count > first && pages[count - 1] == tmp - 1)
> +			swap(tmp, pages[count - 1]);
> +		pages[count++] = tmp;
> +	}
>  
>  	if (r) {
>  		/* If there is any pages in the list put them back to
> 

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer
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RE: [PATCH] drm/ttm: swap consecutive allocated pooled pages v4

[He, Roger]

Reviewed-by: Roger He <Hongbo.He@amd.com>

Thanks
Roger(Hongbo.He)
-----Original Message-----
From: Christian König [mailto:ckoenig.leichtzumerken@gmail.com] 
Sent: Tuesday, December 05, 2017 8:55 PM
To: dri-devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org; He, Roger <Hongbo.He@amd.com>
Subject: [PATCH] drm/ttm: swap consecutive allocated pooled pages v4

When we detect consecutive allocation of pages swap them to avoid accidentally freeing them as huge page.

v2: use swap
v3: check if it's really the first allocated page
v4: don't touch the loop variable

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/ttm/ttm_page_alloc.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index b6f7ce286fb1..44343a2bf55c 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -958,8 +958,15 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
 	r = ttm_page_pool_get_pages(pool, &plist, flags, cstate,
 				    npages - count, 0);
 
-	list_for_each_entry(p, &plist, lru)
-		pages[count++] = p;
+	first = count;
+	list_for_each_entry(p, &plist, lru) {
+		struct page *tmp = p;
+
+		/* Swap the pages if we detect consecutive order */
+		if (count > first && pages[count - 1] == tmp - 1)
+			swap(tmp, pages[count - 1]);
+		pages[count++] = tmp;
+	}
 
 	if (r) {
 		/* If there is any pages in the list put them back to
--
2.11.0

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Re: [PATCH] drm/ttm: swap consecutive allocated pooled pages v4

[Dieter Nützel]

Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>

Dieter

Am 05.12.2017 13:54, schrieb Christian König:
> When we detect consecutive allocation of pages swap them to avoid
> accidentally freeing them as huge page.
> 
> v2: use swap
> v3: check if it's really the first allocated page
> v4: don't touch the loop variable
> 
> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
>  drivers/gpu/drm/ttm/ttm_page_alloc.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c
> b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> index b6f7ce286fb1..44343a2bf55c 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> @@ -958,8 +958,15 @@ static int ttm_get_pages(struct page **pages,
> unsigned npages, int flags,
>  	r = ttm_page_pool_get_pages(pool, &plist, flags, cstate,
>  				    npages - count, 0);
> 
> -	list_for_each_entry(p, &plist, lru)
> -		pages[count++] = p;
> +	first = count;
> +	list_for_each_entry(p, &plist, lru) {
> +		struct page *tmp = p;
> +
> +		/* Swap the pages if we detect consecutive order */
> +		if (count > first && pages[count - 1] == tmp - 1)
> +			swap(tmp, pages[count - 1]);
> +		pages[count++] = tmp;
> +	}
> 
>  	if (r) {
>  		/* If there is any pages in the list put them back to
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Re: [PATCH] drm/ttm: swap consecutive allocated pooled pages v4

[kbuild test robot]

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Hi Christian,

I love your patch! Yet something to improve:

[auto build test ERROR on drm/drm-next]
[also build test ERROR on v4.15-rc2 next-20171206]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Christian-K-nig/drm-ttm-swap-consecutive-allocated-pooled-pages-v4/20171206-191635
base:   git://people.freedesktop.org/~airlied/linux.git drm-next
config: i386-randconfig-x014-201749 (attached as .config)
compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   drivers/gpu//drm/ttm/ttm_page_alloc.c: In function 'ttm_get_pages':
>> drivers/gpu//drm/ttm/ttm_page_alloc.c:924:2: error: 'first' undeclared (first use in this function)
     first = count;
     ^~~~~
   drivers/gpu//drm/ttm/ttm_page_alloc.c:924:2: note: each undeclared identifier is reported only once for each function it appears in

vim +/first +924 drivers/gpu//drm/ttm/ttm_page_alloc.c

   919	
   920		INIT_LIST_HEAD(&plist);
   921		r = ttm_page_pool_get_pages(pool, &plist, flags, cstate,
   922					    npages - count, 0);
   923	
 > 924		first = count;
   925		list_for_each_entry(p, &plist, lru) {
   926			struct page *tmp = p;
   927	
   928			/* Swap the pages if we detect consecutive order */
   929			if (count > first && pages[count - 1] == tmp - 1)
   930				swap(tmp, pages[count - 1]);
   931			pages[count++] = tmp;
   932		}
   933	
   934		if (r) {
   935			/* If there is any pages in the list put them back to
   936			 * the pool.
   937			 */
   938			pr_debug("Failed to allocate extra pages for large request\n");
   939			ttm_put_pages(pages, count, flags, cstate);
   940			return r;
   941		}
   942	
   943		return 0;
   944	}
   945	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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