From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
To: Waiman Long <waiman.long@hp.com>
Cc: linux-arch@vger.kernel.org, Rik van Riel <riel@redhat.com>,
Gleb Natapov <gleb@redhat.com>,
kvm@vger.kernel.org,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
Scott J Norton <scott.norton@hp.com>,
x86@kernel.org, Paolo Bonzini <paolo.bonzini@gmail.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Ingo Molnar <mingo@redhat.com>, Chegu Vinod <chegu_vinod@hp.com>,
David Vrabel <david.vrabel@citrix.com>,
"H. Peter Anvin" <hpa@zytor.com>,
xen-devel@lists.xenproject.org,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>,
Aswin Chandramouleeswaran <aswin@hp.com>
Subject: Re: [PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support
Date: Mon, 07 Apr 2014 23:21:46 +0530 [thread overview]
Message-ID: <5342E5B2.1070306@linux.vnet.ibm.com> (raw)
In-Reply-To: <5342D475.7060503@hp.com>
On 04/07/2014 10:08 PM, Waiman Long wrote:
> On 04/07/2014 02:14 AM, Raghavendra K T wrote:
[...]
>> But I am seeing hang in overcommit cases. Gdb showed that many vcpus
>> are halted and there was no progress. Suspecting the problem /race with
>> halting, I removed the halt() part of kvm_hibernate(). I am yet to
>> take a closer look at the code on halt() related changes.
>
> It seems like there may still be race conditions where the current code
> is not handling correctly. I will look into that to see where the
> problem is. BTW, what test do you use to produce the hang condition?
Running ebizzy on 2 of the vms simultaneously (for sometime in repeated
loop) could reproduce it.
>> Patch series with that change gave around 20% improvement for dbench
>> 2x and 30% improvement for ebizzy 2x cases. (1x has no significant
>> loss/gain).
>>
While at it, Just a correction it was 30% for ebizzy1.5x and around
80% for ebizzy 2x.
> What is the baseline for the performance improvement? Is it without the
> unfair lock and PV qspinlock?
Baseline was 3.14-rc8 without any of the qspin patch series.
next prev parent reply other threads:[~2014-04-07 17:51 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1396445259-27670-1-git-send-email-Waiman.Long@hp.com>
[not found] ` <1396445259-27670-2-git-send-email-Waiman.Long@hp.com>
2014-04-04 13:00 ` [PATCH v8 01/10] qspinlock: A generic 4-byte queue spinlock implementation Peter Zijlstra
2014-04-04 14:59 ` Waiman Long
2014-04-04 17:53 ` Ingo Molnar
2014-04-07 14:16 ` Peter Zijlstra
2014-04-04 16:57 ` Konrad Rzeszutek Wilk
2014-04-04 17:08 ` Waiman Long
2014-04-04 17:54 ` Ingo Molnar
2014-04-07 14:09 ` Peter Zijlstra
2014-04-07 16:59 ` Waiman Long
2014-04-07 14:12 ` Peter Zijlstra
2014-04-07 14:33 ` Konrad Rzeszutek Wilk
[not found] ` <20140402143201.GF12188@phenom.dumpdata.com>
[not found] ` <533C7485.3030203@hp.com>
2014-04-03 2:10 ` [PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support Waiman Long
2014-04-03 17:23 ` Konrad Rzeszutek Wilk
2014-04-04 2:57 ` Waiman Long
2014-04-04 16:55 ` Konrad Rzeszutek Wilk
2014-04-04 17:13 ` Waiman Long
2014-04-04 17:58 ` Konrad Rzeszutek Wilk
2014-04-04 18:33 ` Konrad Rzeszutek Wilk
2014-04-04 18:14 ` Marcos E. Matsunaga
2014-04-04 15:25 ` Konrad Rzeszutek Wilk
2014-04-07 6:14 ` Raghavendra K T
[not found] ` <5342425A.7040005@linux.vnet.ibm.com>
2014-04-07 16:38 ` Waiman Long
2014-04-07 17:51 ` Raghavendra K T [this message]
2014-04-08 19:15 ` Waiman Long
2014-04-09 12:08 ` Raghavendra K T
2014-04-01 20:47 Waiman Long
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