linux-kernel - Re: [PATCH 2/2] sched: Lower chances of cputime scaling overflow

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] [day] [month] [year] [list]

Date:	Wed, 13 Mar 2013 18:53:31 +0100
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Stanislaw Gruszka <sgruszka@...hat.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH 2/2] sched: Lower chances of cputime scaling overflow

2013/3/12 Frederic Weisbecker <fweisbec@...il.com>:
> 2013/3/7 Stanislaw Gruszka <sgruszka@...hat.com>:
>>> +     } else if (!total) {
>>>               stime = rtime;
>>
>> I would prefer stime = rtime/2 (hence utime will be rtime/2 too), but this
>> is not so important.
>
> I can do that.

I eventually kept it that way. Reason is that tasks always spend at
least a bit of time in the kernel when they are scheduled for the
first time. But they might never go to userspace, as in kernel
threads. So I prefer to stuff everything in stime by default. Having
(total == 0 && rtime != 0) should only happen for very low values of
rtime anyway.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/