linux-kernel - Re: [PATCH 2/3] read_lock migrate_disable pushdown to rt_read

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]

Message-ID: <20140125082921.GA3831@opentech.at>
Date:	Sat, 25 Jan 2014 09:29:21 +0100
From:	Nicholas Mc Guire <der.herr@...r.at>
To:	Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc:	Steven Rostedt <rostedt@...dmis.org>,
	linux-rt-users@...r.kernel.org,
	Andreas Platschek <platschek@....tuwien.ac.at>,
	Peter Zijlstra <peterz@...radead.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Carsten Emde <carsten.emde@...dl.org>
Subject: Re: [PATCH 2/3] read_lock migrate_disable pushdown to rt_read_lock

On Fri, 24 Jan 2014, Sebastian Andrzej Siewior wrote:

> * Sebastian Andrzej Siewior | 2013-12-15 16:15:11 [+0100]:
> 
> >* Steven Rostedt | 2013-12-06 10:25:32 [-0500]:
> >
> >>
> >>Let me analyze the original code first. I'll poke peterz and tglx too
> >>to make sure this modification is OK.
> >
> >I took 1/3. I postpone the remaining two until I hear something from
> >you.
> 
> Any news?
>
Carsten Emde added the two patches

   0001-write_lock-migrate_disable-pushdown-to-rt_write_lock.patch
   0002-read_lock-migrate_disable-pushdown-to-rt_read_lock.patch

to the -rt9 test on one of his ARM boards (i.MX6 Sabre automation board)
in the OSADL QA-Farm (rack #9/slot #8)

<snip Carsten Emde>
No complaints so far after adding your patches.

If you would like to follow up:
- Profile: https://www.osadl.org/?id=1822
- Patches: https://www.osadl.org/?id=1822#patches
- Latency plot: https://www.osadl.org/?id=1823
- Munin:
https://www.osadl.org/munin/osadl.org/rack9slot8.osadl.org/index.html
<snip>
 
so it atleast seems to be passing basic testing.

I have an AMD Phenom X4 and Intel i3 running -rt9 with those two patches
applied running stable now for 2 days under alternating load/idle conditions
as well. Unfortunately no further feedback up to now.

Given that its a low-level locking issue I guess that more testing is of little
help and code-reviews would be essential. Notably if any cases could exist
where the order of preempt_disable/lock critical-section unlock/preempt_enable
actually does natter.

thx!
hofrat
--
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/