Re: [PATCH] migration/ram: Fix memory leak when using x-ignore-shared

[Dr. David Alan Gilbert]

* Nikolay Borisov (nborisov@suse.com) wrote:
> During ram initialization for migration dirty/clear bitmaps are
> allocated for all migratable blocks, irrespective of their shared
> status. However, during ram migration cleanup those bitmaps are freed
> only for those blocks which aren't shared, in case x-ignore-shared
> capability is used. This leads to a situation where the bitmaps aren't
> freed for such blocks.

Can you show me where you're seeing the allocation based on MIGRATABLE?
I'm looking at ram_list_init_bitmaps:


        RAMBLOCK_FOREACH_NOT_IGNORED(block) {
            block->bmap = bitmap_new(pages);
....
            block->clear_bmap = bitmap_new(clear_bmap_size(pages, shift));


So that's based on NOT_IGNORED.

Dave

> Fix this by switching the cleanup code to also free bitmaps for all
> migratable blocks.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  migration/ram.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index dc1de9ddbc68..2e40166d2f9e 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -2678,7 +2678,7 @@ static void ram_save_cleanup(void *opaque)
>          }
>      }
>  
> -    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
> +    RAMBLOCK_FOREACH_MIGRATABLE(block) {
>          g_free(block->clear_bmap);
>          block->clear_bmap = NULL;
>          g_free(block->bmap);
> -- 
> 2.34.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK