On 14.09.24 08:37, Barry Song wrote:
From: Barry Song <v-songbaohua@xxxxxxxx> This follows up on the discussion regarding Gaoxu's work[1]. It's unclear if there's still interest in implementing a separate LRU list for lazyfree folios, but I decided to explore it out of curiosity. According to Lokesh, MADV_FREE'd anon folios are expected to be released earlier than file folios. One option, as implemented by Gao Xu, is to place lazyfree anon folios at the tail of the file's `min_seq` generation. However, this approach results in lazyfree folios being released in a LIFO manner, which conflicts with LRU behavior, as noted by Michal. To address this, this patch proposes maintaining a separate list for lazyfree anon folios while keeping them classified under the "file" LRU type to minimize code changes. These lazyfree anon folios will still be counted as file folios and share the same generation with regular files. In the eviction path, the lazyfree list will be prioritized for scanning before the actual file LRU list.
What's the downside of another LRU list? Do we have any experience on that? -- Cheers, David / dhildenb
