lkml.org 
[lkml]   [2014]   [Aug]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] memory-hotplug: fix not enough check of valid zones
(2014/08/27 20:16), Zhang Zhen wrote:
> As Yasuaki Ishimatsu described the check here is not enough
> if memory has hole as follows:
>
> PFN 0x00 0xd0 0xe0 0xf0
> +-------------+-------------+-------------+
> zone type | Normal | hole | Normal |
> +-------------+-------------+-------------+
> In this case, the check can't guarantee that this is "the last
> block of memory".
> The check of ZONE_MOVABLE has the same problem.
>
> Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>

Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

Thanks,
Yasuaki Ishimatsu

> ---
> drivers/base/memory.c | 36 ++++++------------------------------
> 1 file changed, 6 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index ccaf37c..0fc1d25 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -374,20 +374,6 @@ static ssize_t show_phys_device(struct device *dev,
> }
>
> #ifdef CONFIG_MEMORY_HOTREMOVE
> -static int __zones_online_to(unsigned long end_pfn,
> - struct page *first_page, unsigned long nr_pages)
> -{
> - struct zone *zone_next;
> -
> - /* The mem block is the last block of memory. */
> - if (!pfn_valid(end_pfn + 1))
> - return 1;
> - zone_next = page_zone(first_page + nr_pages);
> - if (zone_idx(zone_next) == ZONE_MOVABLE)
> - return 1;
> - return 0;
> -}
> -
> static ssize_t show_zones_online_to(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -407,28 +393,18 @@ static ssize_t show_zones_online_to(struct device *dev,
>
> zone = page_zone(first_page);
>
> -#ifdef CONFIG_HIGHMEM
> - if (zone_idx(zone) == ZONE_HIGHMEM) {
> - if (__zones_online_to(end_pfn, first_page, nr_pages))
> + if (zone_idx(zone) == ZONE_MOVABLE - 1) {
> + /*The mem block is the last memoryblock of this zone.*/
> + if (end_pfn == zone_end_pfn(zone))
> return sprintf(buf, "%s %s\n",
> zone->name, (zone + 1)->name);
> }
> -#else
> - if (zone_idx(zone) == ZONE_NORMAL) {
> - if (__zones_online_to(end_pfn, first_page, nr_pages))
> - return sprintf(buf, "%s %s\n",
> - zone->name, (zone + 1)->name);
> - }
> -#endif
>
> if (zone_idx(zone) == ZONE_MOVABLE) {
> - if (!pfn_valid(start_pfn - nr_pages))
> - return sprintf(buf, "%s %s\n",
> - zone->name, (zone - 1)->name);
> - zone_prev = page_zone(first_page - nr_pages);
> - if (zone_idx(zone_prev) != ZONE_MOVABLE)
> + /*The mem block is the first memoryblock of ZONE_MOVABLE.*/
> + if (start_pfn == zone->zone_start_pfn)
> return sprintf(buf, "%s %s\n",
> - zone->name, (zone - 1)->name);
> + zone->name, (zone - 1)->name);
> }
>
> return sprintf(buf, "%s\n", zone->name);
>




\
 
 \ /
  Last update: 2014-08-28 02:21    [W:0.191 / U:0.608 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site