Re: [Qemu-devel] [PATCH v2 5/6] Don't abort on out of memory when creating page cache

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Orit Wasserman (owasserm@redhat.com) wrote:
> Signed-off-by: Orit Wasserman <owasserm@redhat.com>
> ---
>  arch_init.c  | 18 ++++++++++++++++--
>  page_cache.c | 18 ++++++++++++++----
>  2 files changed, 30 insertions(+), 6 deletions(-)

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> 
> diff --git a/arch_init.c b/arch_init.c
> index 5eff80b..1fa5f1f 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -664,8 +664,22 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
>              DPRINTF("Error creating cache\n");
>              return -1;
>          }
> -        XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
> -        XBZRLE.current_buf = g_malloc(TARGET_PAGE_SIZE);
> +
> +        /* We prefer not to abort if there is no memory */
> +        XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
> +        if (!XBZRLE.encoded_buf) {
> +            DPRINTF("Error allocating encoded_buf\n");
> +            return -1;
> +        }
> +
> +        XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
> +        if (!XBZRLE.current_buf) {
> +            DPRINTF("Error allocating current_buf\n");
> +            g_free(XBZRLE.encoded_buf);
> +            XBZRLE.encoded_buf = NULL;
> +            return -1;
> +        }
> +
>          acct_clear();
>      }
>  
> diff --git a/page_cache.c b/page_cache.c
> index a05db64..62a53f8 100644
> --- a/page_cache.c
> +++ b/page_cache.c
> @@ -60,8 +60,12 @@ PageCache *cache_init(int64_t num_pages, unsigned int page_size)
>          return NULL;
>      }
>  
> -    cache = g_malloc(sizeof(*cache));
> -
> +    /* We prefer not to abort if there is no memory */
> +    cache = g_try_malloc(sizeof(*cache));
> +    if (!cache) {
> +        DPRINTF("Failed to allocate cache\n");
> +        return NULL;
> +    }
>      /* round down to the nearest power of 2 */
>      if (!is_power_of_2(num_pages)) {
>          num_pages = pow2floor(num_pages);
> @@ -74,8 +78,14 @@ PageCache *cache_init(int64_t num_pages, unsigned int page_size)
>  
>      DPRINTF("Setting cache buckets to %" PRId64 "\n", cache->max_num_items);
>  
> -    cache->page_cache = g_malloc((cache->max_num_items) *
> -                                 sizeof(*cache->page_cache));
> +    /* We prefer not to abort if there is no memory */
> +    cache->page_cache = g_try_malloc((cache->max_num_items) *
> +                                     sizeof(*cache->page_cache));
> +    if (!cache->page_cache) {
> +        DPRINTF("Failed to allocate cache->page_cache\n");
> +        g_free(cache);
> +        return NULL;
> +    }
>  
>      for (i = 0; i < cache->max_num_items; i++) {
>          cache->page_cache[i].it_data = NULL;
> -- 
> 1.8.3.1
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK