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| author | Yu Zhao <yuzhao@google.com> | 2022-12-22 05:19:00 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-01-19 02:12:48 +0100 |
| commit | 6df1b2212950aae2b2188c6645ea18e2a9e3fdd5 (patch) | |
| tree | 3c79f9289b93ac20e2bfb7fb27a316c737c72129 /Documentation | |
| parent | mm: multi-gen LRU: rename lru_gen_struct to lru_gen_folio (diff) | |
| download | linux-6df1b2212950aae2b2188c6645ea18e2a9e3fdd5.tar.xz linux-6df1b2212950aae2b2188c6645ea18e2a9e3fdd5.zip | |
mm: multi-gen LRU: rename lrugen->lists[] to lrugen->folios[]
lru_gen_folio will be chained into per-node lists by the coming
lrugen->list.
Link: https://lkml.kernel.org/r/20221222041905.2431096-3-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Larabel <Michael@MichaelLarabel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/mm/multigen_lru.rst | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/mm/multigen_lru.rst b/Documentation/mm/multigen_lru.rst index d7062c6a8946..d8f721f98868 100644 --- a/Documentation/mm/multigen_lru.rst +++ b/Documentation/mm/multigen_lru.rst @@ -89,15 +89,15 @@ variables are monotonically increasing. Generation numbers are truncated into ``order_base_2(MAX_NR_GENS+1)`` bits in order to fit into the gen counter in ``folio->flags``. Each -truncated generation number is an index to ``lrugen->lists[]``. The +truncated generation number is an index to ``lrugen->folios[]``. The sliding window technique is used to track at least ``MIN_NR_GENS`` and at most ``MAX_NR_GENS`` generations. The gen counter stores a value within ``[1, MAX_NR_GENS]`` while a page is on one of -``lrugen->lists[]``; otherwise it stores zero. +``lrugen->folios[]``; otherwise it stores zero. Each generation is divided into multiple tiers. A page accessed ``N`` times through file descriptors is in tier ``order_base_2(N)``. Unlike -generations, tiers do not have dedicated ``lrugen->lists[]``. In +generations, tiers do not have dedicated ``lrugen->folios[]``. In contrast to moving across generations, which requires the LRU lock, moving across tiers only involves atomic operations on ``folio->flags`` and therefore has a negligible cost. A feedback loop @@ -127,7 +127,7 @@ page mapped by this PTE to ``(max_seq%MAX_NR_GENS)+1``. Eviction -------- The eviction consumes old generations. Given an ``lruvec``, it -increments ``min_seq`` when ``lrugen->lists[]`` indexed by +increments ``min_seq`` when ``lrugen->folios[]`` indexed by ``min_seq%MAX_NR_GENS`` becomes empty. To select a type and a tier to evict from, it first compares ``min_seq[]`` to select the older type. If both types are equally old, it selects the one whose first tier has |