linux-kernel - [PATCH v1 -next 0/3] Some optimizations about freezer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240905134130.1176443-1-chenridong@huawei.com>
Date: Thu, 5 Sep 2024 13:41:27 +0000
From: Chen Ridong <chenridong@...wei.com>
To: <tj@...nel.org>, <lizefan.x@...edance.com>, <hannes@...xchg.org>,
	<longman@...hat.com>, <adityakali@...gle.com>, <sergeh@...nel.org>,
	<mkoutny@...e.com>
CC: <cgroups@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<chenridong@...weicloud.com>
Subject: [PATCH v1 -next 0/3] Some optimizations about freezer

We optimized the freezer to reduce redundant loops. We add a selftest to
ensure our optimizations cause no harm, and we confirmed that the
performance can be improved.

We tested the following subtree: D, E, F and G each have n children.
        A
       / \
      B   C
    / | \  \
    D E F   G
   /  |  \   \
 1-n 1-n 1-n  0-n

Our test is to freeze A B C D E F G, and then unfreeze A B C D E F G.
We measured the elapsed time.

	BEFORE(ns)	AFTER(ns)	SAVED(ns)
n=10	142679950	139666014	3,013,936
n=100	199832160	192773032	7,059,128
n=1000	488595100	414901570	73,693,530

As shown above, the larger the value of n, the more significant the time
savings can be. If tested with a deeper hierarchy, the difference could
become even more apparent.

Chen Ridong (3):
  cgroup/freezer: Reduce redundant traversal for cgroup_freeze
  cgroup/freezer: Reduce redundant propagation for
    cgroup_propagate_frozen
  cgroup/freezer: Add freeze selftest

 include/linux/cgroup-defs.h                   |   2 +-
 kernel/cgroup/freezer.c                       |  72 ++++++++----
 .../testing/selftests/cgroup/test_freezer.sh  | 111 ++++++++++++++++++
 3 files changed, 160 insertions(+), 25 deletions(-)
 create mode 100755 tools/testing/selftests/cgroup/test_freezer.sh

-- 
2.34.1