<arei.gong...@huawei.com> wrote:
> From: ChenLiang <chenlian...@huawei.com>
>
> Avoid the hot pages being replaced by others to remarkable decrease cache
> missing. The counter of updating dirty bitmap is used to indicate the cached
> page age.
>
> Signed-off-by: ChenLiang <chenlian...@huawei.com>
> Signed-off-by: Gonglei <arei.gong...@huawei.com>
> /**
> * get_cached_data: Get the data cached for an addr
> @@ -60,13 +62,15 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t
> addr);
> * cache_insert: insert the page into the cache. the page cache
> * will dup the data on insert. the previous value will be overwritten
> *
> - * Returns -1 on error
> + * Returns -1 when the page isn't be inserted into cache
s/be//?
> *
> * @cache pointer to the PageCache struct
> * @addr: page address
> * @pdata: pointer to the page
> + * @current_age indicate the age of the page if the page is inserted into
> cache
missing colon.
* @current_age: current bitmap generation
> @@ -161,6 +171,11 @@ int cache_insert(PageCache *cache, uint64_t addr, const
> uint8_t *pdata)
> /* actual update of entry */
> it = cache_get_by_addr(cache, addr);
>
> + if ((it->it_data != NULL) && (it->it_age +
> + CACHED_PAGE_LIFETIME > current_age)) {
> + /* the cache page is fresh, don't replace it */
Should we add a counter for this "misses"? It is a question to know how
much it happens.
BTW, do you have any benchmark/numbers showing that this is a good idea?
Thanks, Juan.
