linux-kernel - Re: [PATCH RESEND] kthread, tracing: Don't expose half-written comm when creating kthreads

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Date:   Mon, 23 Jul 2018 17:49:36 +0200
From:   Snild Dolkow <snild@...y.com>
To:     Steven Rostedt <rostedt@...dmis.org>
CC:     <linux-kernel@...r.kernel.org>, Ingo Molnar <mingo@...nel.org>,
        Jens Axboe <axboe@...nel.dk>, Tejun Heo <tj@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Peter Enderborg <peter.enderborg@...y.com>,
        Yoshitaka Seto <yoshitaka.seto@...y.com>,
        Oleksiy Avramchenko <oleksiy.avramchenko@...y.com>,
        KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
        John Stultz <john.stultz@...aro.org>
Subject: Re: [PATCH RESEND] kthread, tracing: Don't expose half-written comm
 when creating kthreads

On 07/23/2018 05:37 PM, Steven Rostedt wrote:
> On Mon, 23 Jul 2018 16:23:09 +0200
> Snild Dolkow <snild@...y.com> wrote:
> 
>> On 07/23/2018 03:55 PM, Steven Rostedt wrote:
>>
>>> Can you add a comment here stating something to the affect of:
>>> 		/* task is now visible to other tasks */
>>>
>>> -- Steve  
>> Sure, but isn't that a bit misleading? It will have been visible since
>> some unknown point in time between waking up kthreadd and the return of
>> wait_for_completion(); we're not the ones making it visible.
>>
> 
> I guess that should be reworded, as that is not what I meant, and I
> thought not what I stated. It's stating that the task is now visible,
> not that we are now making it invisible. But I guess I was being too
> short with what I meant. Here's the full statement:
> 
> 		/*
> 		 * task is now visible by other tasks, so updating COMM
> 		 * must be protected.
> 		 */
> 
> -- Steve
> 

Ah. It's the "now" that trips me up. :)

Will add:

		/*
		 * task is already visible to other tasks, so updating
		 * COMM must be protected.
		 */

Any issues with the commit message? Reading it back again now, it doesn't
seem quite as clear as when I wrote it.

//Snild