Re: [Qemu-devel] [PATCH 2/2] xbzrle: Drop unused cache_resize()

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

* Markus Armbruster (armbru@redhat.com) wrote:
> Unused since commit fd8cec XBZRLE: Fix qemu crash when resize the
> xbzrle cache.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

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

Yes, I guess Orit had intended this page_cache to be more general
than xbzrle (which is why I hadn't moved it into migration/)  so perhaps a
user from the future would want that resize, but it's probably best to remove
it for now.

Dave

> ---
>  include/migration/page_cache.h | 11 ---------
>  page_cache.c                   | 56 ------------------------------------------
>  2 files changed, 67 deletions(-)
> 
> diff --git a/include/migration/page_cache.h b/include/migration/page_cache.h
> index 10ed532..4fadd0c 100644
> --- a/include/migration/page_cache.h
> +++ b/include/migration/page_cache.h
> @@ -72,15 +72,4 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr);
>  int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata,
>                   uint64_t current_age);
>  
> -/**
> - * cache_resize: resize the page cache. In case of size reduction the extra
> - * pages will be freed
> - *
> - * Returns -1 on error new cache size on success
> - *
> - * @cache pointer to the PageCache struct
> - * @num_pages: new page cache size (in pages)
> - */
> -int64_t cache_resize(PageCache *cache, int64_t num_pages);
> -
>  #endif
> diff --git a/page_cache.c b/page_cache.c
> index cf8878d..a00a3d9 100644
> --- a/page_cache.c
> +++ b/page_cache.c
> @@ -188,59 +188,3 @@ int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata,
>  
>      return 0;
>  }
> -
> -int64_t cache_resize(PageCache *cache, int64_t new_num_pages)
> -{
> -    PageCache *new_cache;
> -    int64_t i;
> -
> -    CacheItem *old_it, *new_it;
> -
> -    g_assert(cache);
> -
> -    /* cache was not inited */
> -    if (cache->page_cache == NULL) {
> -        return -1;
> -    }
> -
> -    /* same size */
> -    if (pow2floor(new_num_pages) == cache->max_num_items) {
> -        return cache->max_num_items;
> -    }
> -
> -    new_cache = cache_init(new_num_pages, cache->page_size);
> -    if (!(new_cache)) {
> -        DPRINTF("Error creating new cache\n");
> -        return -1;
> -    }
> -
> -    /* move all data from old cache */
> -    for (i = 0; i < cache->max_num_items; i++) {
> -        old_it = &cache->page_cache[i];
> -        if (old_it->it_addr != -1) {
> -            /* check for collision, if there is, keep MRU page */
> -            new_it = cache_get_by_addr(new_cache, old_it->it_addr);
> -            if (new_it->it_data && new_it->it_age >= old_it->it_age) {
> -                /* keep the MRU page */
> -                g_free(old_it->it_data);
> -            } else {
> -                if (!new_it->it_data) {
> -                    new_cache->num_items++;
> -                }
> -                g_free(new_it->it_data);
> -                new_it->it_data = old_it->it_data;
> -                new_it->it_age = old_it->it_age;
> -                new_it->it_addr = old_it->it_addr;
> -            }
> -        }
> -    }
> -
> -    g_free(cache->page_cache);
> -    cache->page_cache = new_cache->page_cache;
> -    cache->max_num_items = new_cache->max_num_items;
> -    cache->num_items = new_cache->num_items;
> -
> -    g_free(new_cache);
> -
> -    return cache->max_num_items;
> -}
> -- 
> 1.9.3
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK