Hi, I would like to propose the following for LSF/MM discussion. Both MM and FS people should be involved. The current way of the slab reclaim is rather suboptimal from 2 perspectives. 1) The slab allocator relies on shrinkers to release pages but shrinkers are object rather than page based. This means that the memory reclaim asks to free some pages, slab asks shrinkers to free some objects and the result might be that nothing really gets freed even though shrinkers do their jobs properly because some objects are still pinning the page. This is not a new problem and it has been discussed in the past. Dave Chinner has even suggested a solution [1] which sounds like the right approach. There was no follow up and I believe we should into implementing it. 2) The way we scale slab reclaim pressure depends on the regular LRU reclaim. There are workloads which do not general a lot of pages on LRUs while they still consume a lot of slab memory. We can end up even going OOM because the slab reclaim doesn't free up enough. I am not really sure how the proper solution should look like but either we need some way of slab consumption throttling or we need a more clever slab pressure estimation. [1] https://lkml.org/lkml/2010/2/8/329. -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
