• Johannes Weiner's avatar
    mm: vmstat: move slab statistics from zone to node counters · 385386cf
    Johannes Weiner authored
    Patch series "mm: per-lruvec slab stats"
    
    Josef is working on a new approach to balancing slab caches and the page
    cache.  For this to work, he needs slab cache statistics on the lruvec
    level.  These patches implement that by adding infrastructure that
    allows updating and reading generic VM stat items per lruvec, then
    switches some existing VM accounting sites, including the slab
    accounting ones, to this new cgroup-aware API.
    
    I'll follow up with more patches on this, because there is actually
    substantial simplification that can be done to the memory controller
    when we replace private memcg accounting with making the existing VM
    accounting sites cgroup-aware.  But this is enough for Josef to base his
    slab reclaim work on, so here goes.
    
    This patch (of 5):
    
    To re-implement slab cache vs.  page cache balancing, we'll need the
    slab counters at the lruvec level, which, ever since lru reclaim was
    moved from the zone to the node, is the intersection of the node, not
    the zone, and the memcg.
    
    We could retain the per-zone counters for when the page allocator dumps
    its memory information on failures, and have counters on both levels -
    which on all but NUMA node 0 is usually redundant.  But let's keep it
    simple for now and just move them.  If anybody complains we can restore
    the per-zone counters.
    
    [hannes@cmpxchg.org: fix oops]
      Link: http://lkml.kernel.org/r/20170605183511.GA8915@cmpxchg.org
    Link: http://lkml.kernel.org/r/20170530181724.27197-3-hannes@cmpxchg.org
    
    Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
    Cc: Josef Bacik <josef@toxicpanda.com>
    Cc: Michal Hocko <mhocko@suse.com>
    Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
    Cc: Rik van Riel <riel@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    385386cf