2020-08-19 10:13:37

by David Hildenbrand

Subject: [PATCH v1 03/11] mm/memory_hotplug: simplify checking if all pages are isolated in offline_pages()

We make sure that we cannot have any memory holes right at the beginning
of offline_pages(). We no longer need walk_system_ram_range() and can
call test_pages_isolated() directly.

Cc: Andrew Morton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: Oscar Salvador <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
---
mm/memory_hotplug.c | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 6856702af68d9..f64478349148d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1384,17 +1384,6 @@ offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
return 0;
}

-/*
- * Check all pages in range, recorded as memory resource, are isolated.
- */
-static int
-check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
- void *data)
-{
- return test_pages_isolated(start_pfn, start_pfn + nr_pages,
- MEMORY_OFFLINE);
-}
-
static int __init cmdline_parse_movable_node(char *p)
{
movable_node_enabled = true;
@@ -1579,10 +1568,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
reason = "failure to dissolve huge pages";
goto failed_removal_isolated;
}
- /* check again */
- ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn,
- NULL, check_pages_isolated_cb);
- } while (ret);
+ } while (test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE));

/* Ok, all of our target is isolated.
We cannot do rollback at this point. */
--
2.26.2

2020-08-19 12:40:55

by Michal Hocko

Subject: Re: [PATCH v1 03/11] mm/memory_hotplug: simplify checking if all pages are isolated in offline_pages()

On Wed 19-08-20 12:11:49, David Hildenbrand wrote:
> We make sure that we cannot have any memory holes right at the beginning
> of offline_pages(). We no longer need walk_system_ram_range() and can
> call test_pages_isolated() directly.
>
> Cc: Andrew Morton <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Wei Yang <[email protected]>
> Cc: Baoquan He <[email protected]>
> Cc: Pankaj Gupta <[email protected]>
> Cc: Oscar Salvador <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>

Acked-by: Michal Hocko <[email protected]>

> ---
> mm/memory_hotplug.c | 16 +---------------
> 1 file changed, 1 insertion(+), 15 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 6856702af68d9..f64478349148d 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1384,17 +1384,6 @@ offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
> return 0;
> }
>
> -/*
> - * Check all pages in range, recorded as memory resource, are isolated.
> - */
> -static int
> -check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
> - void *data)
> -{
> - return test_pages_isolated(start_pfn, start_pfn + nr_pages,
> - MEMORY_OFFLINE);
> -}
> -
> static int __init cmdline_parse_movable_node(char *p)
> {
> movable_node_enabled = true;
> @@ -1579,10 +1568,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
> reason = "failure to dissolve huge pages";
> goto failed_removal_isolated;
> }
> - /* check again */
> - ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn,
> - NULL, check_pages_isolated_cb);
> - } while (ret);
> + } while (test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE));
>
> /* Ok, all of our target is isolated.
> We cannot do rollback at this point. */
> --
> 2.26.2

--
Michal Hocko
SUSE Labs

2020-08-31 10:13:48

by Pankaj Gupta

Subject: Re: [PATCH v1 03/11] mm/memory_hotplug: simplify checking if all pages are isolated in offline_pages()

> We make sure that we cannot have any memory holes right at the beginning
> of offline_pages(). We no longer need walk_system_ram_range() and can
> call test_pages_isolated() directly.
>
> Cc: Andrew Morton <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Wei Yang <[email protected]>
> Cc: Baoquan He <[email protected]>
> Cc: Pankaj Gupta <[email protected]>
> Cc: Oscar Salvador <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> mm/memory_hotplug.c | 16 +---------------
> 1 file changed, 1 insertion(+), 15 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 6856702af68d9..f64478349148d 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1384,17 +1384,6 @@ offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
> return 0;
> }
>
> -/*
> - * Check all pages in range, recorded as memory resource, are isolated.
> - */
> -static int
> -check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
> - void *data)
> -{
> - return test_pages_isolated(start_pfn, start_pfn + nr_pages,
> - MEMORY_OFFLINE);
> -}
> -
> static int __init cmdline_parse_movable_node(char *p)
> {
> movable_node_enabled = true;
> @@ -1579,10 +1568,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
> reason = "failure to dissolve huge pages";
> goto failed_removal_isolated;
> }
> - /* check again */
> - ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn,
> - NULL, check_pages_isolated_cb);
> - } while (ret);
> + } while (test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE));
>
> /* Ok, all of our target is isolated.
> We cannot do rollback at this point. */
> --
> 2.26.2

Acked-by: Pankaj Gupta <[email protected]>