Do you know how the le9 patch compares to mg_lru? The latter applies to all memory, not just files as far as I can tell. The former might still be useful in preventing eager OOM while still keeping executable file-backed pages in memory?
le9 is a 'simple' method to keep the fixed amount of the page cache. It works exceptionally well for what it is, but it requires manual tuning of the amount of cache in MB.
MGLRU is basically a smarter version of already existing eviction algorithm, with evicts (or keeps) both page cache and anon pages, and combined with min_ttl_ms it tries to keep current active page cache for a specified amount of time. It still takes into account swappiness and does not operate on a fixed amount of page cache, unlike le9.
Both are effective in trashing prevention, both are different. MGLRU, especially with higher min_ttl_ms, could cause OOM killer more frequently than you'd like it to be called. I find le9 more effective for desktop use on old low-end machines, but that's only because it just keeps the (large/er amounts of) page cache. It's not very preferable for embedded systems for example.
