laoar

From e75fa7b22e766aa6c7b87aecb30d552fb1d2b386 Mon Sep 17 00:00:00 2001
From: Yafang Shao <[email protected]>
Date: Mon, 16 Dec 2019 05:09:31 -0500
Subject: [PATCH 2/5] mm, memcg: introduce MEMCG_PROT_SKIP for memcg zero usage
 case

If the usage of a memcg is zero, we don't need to do useless work to scan
it. That is a minor optimization.

Cc: Roman Gushchin <[email protected]>

laoar

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9b3c5df75..16fc88b3f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -416,6 +416,8 @@ struct address_space {
        unsigned long           nrpages;        /* number of total pages */
        /* number of shadow or DAX exceptional entries */
        unsigned long           nrexceptional;
+       unsigned long           nractive;
+       unsigned long           nrinactive;

laoar

Subject: [PATCH 1/1] mm, fadvise: improve the expensive remote LRU cache
 draining after FADV_DONTNEED

Our users reported that there're some random latency spikes when their RT
process is running. Finally we found that latency spike is caused by
FADV_DONTNEED. Which may call lru_add_drain_all() to drain LRU cache on
remote CPUs, and then waits the per-cpu work to complete. The wait time
is uncertain, which may be tens millisecond.
That behavior is unreasonable, because this process is bound to a
specific CPU and the file is only accessed by itself, IOW, there should

laoar

校招内推 | 拼多多 | 简历优先安排

• 报名自即日起至6月30日

• 面向毕业时间在2024年9月-2025年8月期间的同学

• 招聘详情：还没找到心仪工作？拼多多集团-PDD春招「技术专场」，等你上岸

• 6大岗位，内推简历优先筛选：
  服务端研发工程师 / 算法工程师 / Web前端研发工程师