linux-kernel - Re: Another SCHED_DEADLINE bug (with bisection and possible fix)

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:	Sat, 31 Jan 2015 10:56:59 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Juri Lelli <juri.lelli@....com>
Cc:	Luca Abeni <luca.abeni@...tn.it>, Kirill Tkhai <tkhai@...dex.ru>,
	Ingo Molnar <mingo@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: Another SCHED_DEADLINE bug (with bisection and possible fix)

On Fri, Jan 30, 2015 at 10:35:02AM +0000, Juri Lelli wrote:
> So, we do the safe thing only in case of throttling.

No, even for the !throttle aka running tasks. We only use
dl_{runtime,deadline,period} for replenishment, until that time we
observe the old runtime/deadline set by the previous replenishment.

> I guess is more than
> ok for now, while we hopefully find some spare cycle to implement a
> complete solution :/.

Yeah, I bet the fun part is computing the 0-lag across the entire root
domain, per-cpu 0-lag isn't correct afaict.
--
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/