linux-kernel - Re: [PATCH v2] workqueue: Do not set CPU_INTENSIVE worker flags with wq_cpu_intensive_thresh

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

Message-ID: <ZG_JuzyP_1FHIC6L@slm.duckdns.org>
Date:   Thu, 25 May 2023 10:48:59 -1000
From:   Tejun Heo <tj@...nel.org>
To:     Zqiang <qiang.zhang1211@...il.com>
Cc:     jiangshanlai@...il.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] workqueue: Do not set CPU_INTENSIVE worker flags with
 wq_cpu_intensive_thresh_us=0

Hello,

I rewrote the patch description and separated it out into a separate if
statement for readability. Applied to wq/for-6.5.

Thanks.

>From 18c8ae813156a6855f026de80fffb91e1a28ab3d Mon Sep 17 00:00:00 2001
From: Zqiang <qiang.zhang1211@...il.com>
Date: Thu, 25 May 2023 12:00:38 +0800
Subject: [PATCH] workqueue: Disable per-cpu CPU hog detection when
 wq_cpu_intensive_thresh_us is 0

If workqueue.cpu_intensive_thresh_us is set to 0, the detection mechanism
for CPU-hogging per-cpu work item will keep triggering spuriously:

  workqueue: process_srcu hogged CPU for >0us 4 times, consider switching to WQ_UNBOUND
  workqueue: gc_worker hogged CPU for >0us 4 times, consider switching to WQ_UNBOUND
  workqueue: gc_worker hogged CPU for >0us 8 times, consider switching to WQ_UNBOUND
  workqueue: wait_rcu_exp_gp hogged CPU for >0us 4 times, consider switching to WQ_UNBOUND
  workqueue: kfree_rcu_monitor hogged CPU for >0us 4 times, consider switching to WQ_UNBOUND
  workqueue: kfree_rcu_monitor hogged CPU for >0us 8 times, consider switching to WQ_UNBOUND
  workqueue: reg_todo hogged CPU for >0us 4 times, consider switching to WQ_UNBOUND

This commit therefore disables the CPU-hog detection mechanism when
workqueue.cpu_intensive_thresh_us is set to 0.

tj: Patch description updated and the condition check on
    cpu_intensive_thresh_us separated into a separate if statement for
    readability.

Signed-off-by: Zqiang <qiang.zhang1211@...il.com>

Can you please use your full name as in "FIRST_NAME LAST_NAME <EMAIL>" when
signing-off patches in the future?

Thanks.

--
tejun