linux-kernel - Re: [PATCH] perf, x86: P4 PMU -- Fix unflagged overflows test

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:	Mon, 07 Feb 2011 20:22:21 +0300
From:	Cyrill Gorcunov <gorcunov@...il.com>
To:	Don Zickus <dzickus@...hat.com>
CC:	Ingo Molnar <mingo@...e.hu>, George Spelvin <linux@...izon.com>,
	Meelis Roos <mroos@...ux.ee>, Lin Ming <ming.m.lin@...el.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	lkml <linux-kernel@...r.kernel.org>,
	Jason Wessel <jason.wessel@...driver.com>
Subject: Re: [PATCH] perf, x86: P4 PMU -- Fix unflagged overflows test

On 02/06/2011 10:21 PM, Cyrill Gorcunov wrote:
> On 02/04/2011 07:59 PM, Don Zickus wrote:
>> On Fri, Feb 04, 2011 at 03:17:28PM +0300, Cyrill Gorcunov wrote:
>>> Please apply it, sorry for non-inlined patch (have a web access only at moment).
>>>
>>> Note that I've tested the patch on non-HT machine so if someone have HT'ed one
>>> -- it would be great to test the patch there.
>>
>> Hmm. For some reason, when I enable the kgdb testsuite, the box fails to
>> boot with hardlockup issues.  It seems like the code is swallowing the
>> NMIs? I basically applied this patch on top of 2.6.38-rc3 and ran it on my
>> Xeon box (p4 w/HT).
>>
>> Cheers,
>> Don
> 
>   Don, I hope to get access to p4 machine tomorrow and investigate this issue
> (didn't manage to read kgdb code this weekend). Sorry for delay.
> 

  Just for info -- I've tested the patch on p4 machine with kgdb bootup tests
and results are somehow strange. If I disable nmi-watchdog the tests passes
fine and i'm able to run perf top (or anything related). Same time if I leave
nmi-watchdog enabled by default the borrowed event reported, kgdb tests passes
but nmi-watchdog never fires (ie I see nmi irq counter remains zero). So I've added
debug prints and found that counter reaches positive values and didn't issues
nmi at all. All in one -- i'm still investigating this issue unfortunatelly
the kernel build procedure sometime takes hours on this machine (even with
ccache enabled) so it goes a way slower then I expected :(
-- 
    Cyrill
--
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/