Hi, Joonsoo
On Mon, Jun 16, 2014 at 02:40:43PM +0900, Joonsoo Kim wrote:
> We should free memory for bitmap when we find zone mis-match,
> otherwise this memory will leak.
>
> Additionally, I copy code comment from PPC KVM's CMA code to inform
> why we need to check zone mis-match.
>
> * Note
> Minchan suggested to add a tag for the stable, but, I don't do it,
> because I found this possibility during code-review and, IMO,
> this patch isn't suitable for stable tree.
Nice idea to put the comment in here. Thanks Joonsoo.
It seems you obey "It must fix a real bug that bothers people"
on Documentation/stable_kernel_rules.txt but it's a really obvious
bug and hard to get a report from people because limited user and
hard to detect small such small memory leak.
In my experince, Andrew perfered stable marking for such a obvious
problem but simple fix like this but not sure so let's pass the decision
to him and will learn a lesson from him and will follow the decision
from now on.
Thanks.
Acked-by: Minchan Kim <minc...@kernel.org>
>
> Acked-by: Zhang Yanfei <zhangyan...@cn.fujitsu.com>
> Reviewed-by: Michal Nazarewicz <min...@mina86.com>
> Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
> Signed-off-by: Joonsoo Kim <iamjoonsoo....@lge.com>
>
> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index 83969f8..6467c91 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -176,14 +176,24 @@ static int __init cma_activate_area(struct cma *cma)
> base_pfn = pfn;
> for (j = pageblock_nr_pages; j; --j, pfn++) {
> WARN_ON_ONCE(!pfn_valid(pfn));
> + /*
> + * alloc_contig_range requires the pfn range
> + * specified to be in the same zone. Make this
> + * simple by forcing the entire CMA resv range
> + * to be in the same zone.
> + */
> if (page_zone(pfn_to_page(pfn)) != zone)
> - return -EINVAL;
> + goto err;
> }
> init_cma_reserved_pageblock(pfn_to_page(base_pfn));
> } while (--i);
>
> mutex_init(&cma->lock);
> return 0;
> +
> +err:
> + kfree(cma->bitmap);
> + return -EINVAL;
> }
>
> static struct cma cma_areas[MAX_CMA_AREAS];
> --
> 1.7.9.5
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majord...@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"d...@kvack.org";> em...@kvack.org </a>
--
Kind regards,
Minchan Kim
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
