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| author |   Yu Zhao <yuzhao@google.com> | 2023-12-07 23:14:07 -0700 |
|---|---|---|
| committer |   Andrew Morton <akpm@linux-foundation.org> | 2023-12-12 17:20:20 -0800 |
| commit | 4376807bf2d5371c3e00080c972be568c3f8a7d1 (patch) | |
| tree | 3511cfbb0098374a82d1ab0cbafdb6da9dad8bcf /include/linux/mmzone.h | |
| parent | mm/mglru: respect min_ttl_ms with memcgs (diff) | |
| download | wireguard-linux-4376807bf2d5371c3e00080c972be568c3f8a7d1.tar.xz wireguard-linux-4376807bf2d5371c3e00080c972be568c3f8a7d1.zip | |
mm/mglru: reclaim offlined memcgs harder
In the effort to reduce zombie memcgs [1], it was discovered that the
memcg LRU doesn't apply enough pressure on offlined memcgs. Specifically,
instead of rotating them to the tail of the current generation
(MEMCG_LRU_TAIL) for a second attempt, it moves them to the next
generation (MEMCG_LRU_YOUNG) after the first attempt.
Not applying enough pressure on offlined memcgs can cause them to build
up, and this can be particularly harmful to memory-constrained systems.
On Pixel 8 Pro, launching apps for 50 cycles:
Before After Change
Zombie memcgs 45 35 -22%
[1] https://lore.kernel.org/CABdmKX2M6koq4Q0Cmp_-=wbP0Qa190HdEGGaHfxNS05gAkUtPA@mail.gmail.com/
Link: https://lkml.kernel.org/r/20231208061407.2125867-4-yuzhao@google.com
Fixes: e4dde56cd208 ("mm: multi-gen LRU: per-node lru_gen_folio lists")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reported-by: T.J. Mercier <tjmercier@google.com>
Tested-by: T.J. Mercier <tjmercier@google.com>
Cc: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jaroslav Pulchart <jaroslav.pulchart@gooddata.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 23533b12bee2..9db36e197712 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -519,10 +519,10 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw); * 1. Exceeding the soft limit, which triggers MEMCG_LRU_HEAD; * 2. The first attempt to reclaim a memcg below low, which triggers * MEMCG_LRU_TAIL; - * 3. The first attempt to reclaim a memcg below reclaimable size threshold, - * which triggers MEMCG_LRU_TAIL; - * 4. The second attempt to reclaim a memcg below reclaimable size threshold, - * which triggers MEMCG_LRU_YOUNG; + * 3. The first attempt to reclaim a memcg offlined or below reclaimable size + * threshold, which triggers MEMCG_LRU_TAIL; + * 4. The second attempt to reclaim a memcg offlined or below reclaimable size + * threshold, which triggers MEMCG_LRU_YOUNG; * 5. Attempting to reclaim a memcg below min, which triggers MEMCG_LRU_YOUNG; * 6. Finishing the aging on the eviction path, which triggers MEMCG_LRU_YOUNG; * 7. Offlining a memcg, which triggers MEMCG_LRU_OLD. |