linux-kernel - Re: [PATCH v5 1/2] printk: Add console owner and waiter logic to load balance console writes

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]

Date:   Thu, 18 Jan 2018 19:20:23 -0500
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Pavel Machek <pavel@....cz>
Cc:     Petr Mladek <pmladek@...e.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        akpm@...ux-foundation.org, linux-mm@...ck.org,
        Cong Wang <xiyou.wangcong@...il.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Mel Gorman <mgorman@...e.de>, Michal Hocko <mhocko@...nel.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Peter Zijlstra <peterz@...radead.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Jan Kara <jack@...e.cz>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
        rostedt@...e.goodmis.org, Byungchul Park <byungchul.park@....com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Tejun Heo <tj@...nel.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 1/2] printk: Add console owner and waiter logic to
 load balance console writes

On Thu, 18 Jan 2018 23:03:24 +0100
Pavel Machek <pavel@....cz> wrote:


> > To demonstrate the issue, this module has been shown to lock up a
> > system with 4 CPUs and a slow console (like a serial console). It is
> > also able to lock up a 8 CPU system with only a fast (VGA) console, by
> > passing in "loops=100". The changes in this commit prevent this module
> > from locking up the system.
> > 
> > #include <linux/module.h>
> > #include <linux/delay.h>
> > #include <linux/sched.h>
> > #include <linux/mutex.h>
> > #include <linux/workqueue.h>
> > #include <linux/hrtimer.h>  
> 
> Programs in commit messages. Not preffered way to distribute code, I'd
> say. What about putting it into kernel selftests directory or
> something like that?

It's not really a program, but a module. I could add a real module that
can test this, and people can modprobe it if they want to make sure
there's no regressions.

I can send a patch.

-- Steve