From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
linux-doc@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
Jan Kiszka <jan.kiszka@siemens.com>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Paul Mackerras <paulus@samba.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Xen <xen-devel@lists.xensource.com>,
Dave Jiang <dave.jiang@intel.com>, KVM <kvm@vger.kernel.org>,
Glauber Costa <glommer@redhat.com>, X86 <x86@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Avi Kivity <avi@redhat.com>,
Rik van Riel <riel@redhat.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Sasha Levin <levinsasha928@gmail.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Virtualization <virtualization@lists.linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Suzuki Poulose <suzuki@linux.vn
Subject: Re: [PATCH RFC V4 0/5] kvm : Paravirt-spinlock support for KVM guests
Date: Wed, 25 Jan 2012 23:15:36 +0530 [thread overview]
Message-ID: <4F203FC0.70907@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120125163552.GB23999@phenom.dumpdata.com>
On 01/25/2012 10:05 PM, Konrad Rzeszutek Wilk wrote:
>> So it seems we have worst case overhead of around 8%. But we see
>> improvement of at-least 15% once when little more time is spent in
>> critical section.
>
> Is this with collecting the histogram information about spinlocks? We found
> that if you enable that for production runs it makes them quite slower.
>
Ok. Are you referring to CONFIG_KVM_DEBUG_FS/CONFIG_XEN_DEBUG_FS?. Not
it was not enabled. But then may be I was not precise. This test was
only on native. So it should have not affected IMO.
It is nice to know that histogram affects, since I was always under the
impression that it does not affect much on guest too. My experiments
had almost always enabled that.
Let me know if you referred to something else..
WARNING: multiple messages have this Message-ID (diff)
From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
linux-doc@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
Jan Kiszka <jan.kiszka@siemens.com>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Paul Mackerras <paulus@samba.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Xen <xen-devel@lists.xensource.com>,
Dave Jiang <dave.jiang@intel.com>, KVM <kvm@vger.kernel.org>,
Glauber Costa <glommer@redhat.com>, X86 <x86@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Avi Kivity <avi@redhat.com>,
Rik van Riel <riel@redhat.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Sasha Levin <levinsasha928@gmail.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Virtualization <virtualization@lists.linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Suzuki Poulose <suzuki@linux.vn>
Subject: Re: [PATCH RFC V4 0/5] kvm : Paravirt-spinlock support for KVM guests
Date: Wed, 25 Jan 2012 23:15:36 +0530 [thread overview]
Message-ID: <4F203FC0.70907@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120125163552.GB23999@phenom.dumpdata.com>
On 01/25/2012 10:05 PM, Konrad Rzeszutek Wilk wrote:
>> So it seems we have worst case overhead of around 8%. But we see
>> improvement of at-least 15% once when little more time is spent in
>> critical section.
>
> Is this with collecting the histogram information about spinlocks? We found
> that if you enable that for production runs it makes them quite slower.
>
Ok. Are you referring to CONFIG_KVM_DEBUG_FS/CONFIG_XEN_DEBUG_FS?. Not
it was not enabled. But then may be I was not precise. This test was
only on native. So it should have not affected IMO.
It is nice to know that histogram affects, since I was always under the
impression that it does not affect much on guest too. My experiments
had almost always enabled that.
Let me know if you referred to something else..
next prev parent reply other threads:[~2012-01-25 17:45 UTC|newest]
Thread overview: 139+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-14 18:25 [PATCH RFC V4 0/5] kvm : Paravirt-spinlock support for KVM guests Raghavendra K T
2012-01-14 18:25 ` Raghavendra K T
2012-01-14 18:25 ` Raghavendra K T
2012-01-14 18:25 ` [PATCH RFC V4 1/5] debugfs: Add support to print u32 array in debugfs Raghavendra K T
2012-01-14 18:25 ` Raghavendra K T
2012-01-14 18:25 ` Raghavendra K T
2012-01-14 18:25 ` [PATCH RFC V4 2/5] kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks Raghavendra K T
2012-01-14 18:25 ` Raghavendra K T
2012-01-14 18:25 ` Raghavendra K T
2012-01-16 3:24 ` Alexander Graf
2012-01-16 3:24 ` Alexander Graf
2012-01-16 8:43 ` Raghavendra K T
2012-01-16 8:43 ` Raghavendra K T
2012-01-16 9:03 ` Avi Kivity
2012-01-16 9:03 ` Avi Kivity
2012-01-16 9:55 ` Raghavendra K T
2012-01-16 9:55 ` Raghavendra K T
2012-01-14 18:26 ` [PATCH RFC V4 3/5] kvm guest : Added configuration support to enable debug information for KVM Guests Raghavendra K T
2012-01-14 18:26 ` Raghavendra K T
2012-01-14 18:26 ` Raghavendra K T
2012-01-14 18:26 ` [PATCH RFC V4 4/5] kvm : pv-ticketlocks support for linux guests running on KVM hypervisor Raghavendra K T
2012-01-14 18:26 ` Raghavendra K T
2012-01-14 18:26 ` Raghavendra K T
2012-01-16 3:12 ` Alexander Graf
2012-01-16 3:12 ` Alexander Graf
2012-01-16 7:25 ` Raghavendra K T
2012-01-16 7:25 ` Raghavendra K T
2012-01-16 9:05 ` Avi Kivity
2012-01-16 9:05 ` Avi Kivity
2012-01-16 14:13 ` Raghavendra K T
2012-01-16 14:13 ` Raghavendra K T
2012-01-16 14:47 ` Avi Kivity
2012-01-16 14:47 ` Avi Kivity
2012-01-16 23:49 ` Jeremy Fitzhardinge
2012-01-16 23:49 ` Jeremy Fitzhardinge
2012-01-17 11:02 ` Marcelo Tosatti
2012-01-17 11:02 ` Marcelo Tosatti
2012-01-17 11:33 ` Srivatsa Vaddagiri
2012-01-17 11:33 ` Srivatsa Vaddagiri
2012-01-18 1:34 ` Jeremy Fitzhardinge
2012-01-18 1:34 ` Jeremy Fitzhardinge
2012-01-18 13:54 ` Srivatsa Vaddagiri
2012-01-18 13:54 ` Srivatsa Vaddagiri
2012-01-18 21:52 ` Jeremy Fitzhardinge
2012-01-18 21:52 ` Jeremy Fitzhardinge
2012-01-24 14:08 ` Avi Kivity
2012-01-24 14:08 ` Avi Kivity
2012-01-24 18:51 ` Raghavendra K T
2012-01-24 18:51 ` Raghavendra K T
2012-01-17 18:57 ` Raghavendra K T
2012-01-17 18:57 ` Raghavendra K T
2012-01-24 19:01 ` Raghavendra K T
2012-01-14 18:27 ` [PATCH RFC V4 5/5] Documentation/kvm : Add documentation on Hypercalls and features used for PV spinlock Raghavendra K T
2012-01-14 18:27 ` Raghavendra K T
2012-01-14 18:27 ` Raghavendra K T
2012-01-14 18:27 ` Raghavendra K T
2012-01-16 3:23 ` Alexander Graf
2012-01-16 3:23 ` Alexander Graf
2012-01-16 3:51 ` Srivatsa Vaddagiri
2012-01-16 3:51 ` Srivatsa Vaddagiri
2012-01-16 4:00 ` Alexander Graf
2012-01-16 4:00 ` Alexander Graf
2012-01-16 8:47 ` Avi Kivity
2012-01-16 8:44 ` Raghavendra K T
2012-01-16 8:44 ` Raghavendra K T
2012-01-16 10:26 ` Alexander Graf
2012-01-16 10:26 ` Alexander Graf
2012-01-16 9:00 ` Avi Kivity
2012-01-16 9:00 ` Avi Kivity
2012-01-16 9:40 ` Srivatsa Vaddagiri
2012-01-16 10:14 ` Avi Kivity
2012-01-16 14:11 ` Srivatsa Vaddagiri
2012-01-17 9:14 ` Gleb Natapov
2012-01-17 9:14 ` Gleb Natapov
2012-01-17 12:26 ` Srivatsa Vaddagiri
2012-01-17 12:26 ` Srivatsa Vaddagiri
2012-01-17 12:51 ` Gleb Natapov
2012-01-17 12:51 ` Gleb Natapov
2012-01-17 13:11 ` Srivatsa Vaddagiri
2012-01-17 13:11 ` Srivatsa Vaddagiri
2012-01-17 13:20 ` Gleb Natapov
2012-01-17 13:20 ` Gleb Natapov
2012-01-17 14:28 ` Srivatsa Vaddagiri
2012-01-17 14:28 ` Srivatsa Vaddagiri
2012-01-17 15:32 ` Gleb Natapov
2012-01-17 15:32 ` Gleb Natapov
2012-01-17 15:53 ` Marcelo Tosatti
2012-01-17 15:53 ` Marcelo Tosatti
2012-01-20 15:09 ` Srivatsa Vaddagiri
2012-01-17 13:13 ` Raghavendra K T
2012-01-17 13:13 ` Raghavendra K T
2012-01-16 3:57 ` [PATCH RFC V4 0/5] kvm : Paravirt-spinlock support for KVM guests Alexander Graf
2012-01-16 3:57 ` Alexander Graf
2012-01-16 6:40 ` Jeremy Fitzhardinge
2012-01-16 6:40 ` Jeremy Fitzhardinge
2012-01-16 8:55 ` Avi Kivity
2012-01-16 8:55 ` Avi Kivity
2012-01-16 23:59 ` Jeremy Fitzhardinge
2012-01-16 23:59 ` Jeremy Fitzhardinge
2012-01-18 10:48 ` Raghavendra K T
2012-01-18 10:48 ` Raghavendra K T
2012-01-16 10:24 ` Alexander Graf
2012-01-16 10:24 ` Alexander Graf
2012-01-17 0:30 ` Jeremy Fitzhardinge
2012-01-17 0:30 ` Jeremy Fitzhardinge
2012-01-18 10:23 ` Raghavendra K T
2012-01-18 10:23 ` Raghavendra K T
2012-01-16 13:43 ` Raghavendra K T
2012-01-16 13:43 ` Raghavendra K T
2012-01-16 13:49 ` Avi Kivity
2012-01-16 13:49 ` Avi Kivity
2012-01-16 18:48 ` Raghavendra K T
2012-01-16 18:48 ` Raghavendra K T
2012-01-16 14:20 ` Srivatsa Vaddagiri
2012-01-16 14:20 ` Srivatsa Vaddagiri
2012-01-16 14:23 ` Alexander Graf
2012-01-16 14:23 ` Alexander Graf
2012-01-16 18:38 ` Raghavendra K T
2012-01-16 18:38 ` Raghavendra K T
2012-01-16 18:42 ` Alexander Graf
2012-01-16 18:42 ` Alexander Graf
2012-01-17 17:27 ` Raghavendra K T
2012-01-17 17:27 ` Raghavendra K T
2012-01-17 17:39 ` Alexander Graf
2012-01-17 17:39 ` Alexander Graf
2012-01-17 18:36 ` Raghavendra K T
2012-01-17 18:36 ` Raghavendra K T
2012-01-17 21:57 ` Dave Hansen
2012-01-17 21:57 ` Dave Hansen
2012-01-18 2:27 ` Raghavendra K T
2012-01-18 2:27 ` Raghavendra K T
2012-01-25 8:55 ` Raghavendra K T
2012-01-25 8:55 ` Raghavendra K T
2012-01-25 16:35 ` Konrad Rzeszutek Wilk
2012-01-25 16:35 ` Konrad Rzeszutek Wilk
2012-01-25 17:45 ` Raghavendra K T [this message]
2012-01-25 17:45 ` Raghavendra K T
2012-01-25 19:05 ` Konrad Rzeszutek Wilk
2012-01-25 19:05 ` Konrad Rzeszutek Wilk
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4F203FC0.70907@linux.vnet.ibm.com \
--to=raghavendra.kt@linux.vnet.ibm.com \
--cc=avi@redhat.com \
--cc=dave.jiang@intel.com \
--cc=dave@linux.vnet.ibm.com \
--cc=glommer@redhat.com \
--cc=gregkh@suse.de \
--cc=hpa@zytor.com \
--cc=jan.kiszka@siemens.com \
--cc=jeremy@goop.org \
--cc=konrad.wilk@oracle.com \
--cc=kvm@vger.kernel.org \
--cc=levinsasha928@gmail.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=paulus@samba.org \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=sedat.dilek@gmail.com \
--cc=stefano.stabellini@eu.citrix.com \
--cc=suzuki@linux.vn \
--cc=tglx@linutronix.de \
--cc=vatsa@linux.vnet.ibm.com \
--cc=virtualization@lists.linux-foundation.org \
--cc=x86@kernel.org \
--cc=xen-devel@lists.xensource.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.