From mboxrd@z Thu Jan  1 00:00:00 1970
From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Subject: Re: [PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support
Date: Wed, 09 Apr 2014 17:38:11 +0530
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To: Waiman Long <waiman.long@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>, Peter Zijlstra <peterz@infradead.org>, linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, Paolo Bonzini <paolo.bonzini@gmail.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>, Rik van Riel <riel@redhat.com>, Linus Torvalds <torvalds@linux-foundation.org>, David Vrabel <david.vrabel@citrix.com>, Oleg Nesterov <oleg@redhat.com>, Gleb Natapov <gleb@redhat.com>, Aswin Chandramouleeswaran <aswin@hp.com>, Scott J Norton <scott.norton@hp.com>, Chegu Vinod <chegu_vinod@hp.com>

On 04/09/2014 12:45 AM, Waiman Long wrote:
> Yes, I am able to reproduce the hang problem with ebizzy. BTW, could you
> try to apply the attached patch file on top of the v8 patch series to
> see if it can fix the hang problem?

Ran the benchmarks with the fix and I am not seeing hang so far.
ebizzy improvements.

0.5x  2.7345
1x   -10.6593
1.5x  35.6962
2x    88.0461

dbench improvements
0.5x   3.2428
1x     1.1514
1.5x   5.5071
2x    23.8700
( I will have to restest on ebizzy 1x reression but overall performance
numbers look good).

>> Baseline was 3.14-rc8 without any of the qspin patch series.
>>
>
> Does the baseline have PV ticketlock or without any PV support?

baseline had PV ticketlock enabled.