linux-kernel - RE: about the time consuming kvm_vcpu

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>] [day] [month] [year] [list]

Message-ID: <F2CBF3009FA73547804AE4C663CAB28E58A462@shsmsx102.ccr.corp.intel.com>
Date:	Thu, 6 Aug 2015 05:58:36 +0000
From:	"Li, Liang Z" <liang.z.li@...el.com>
To:	Paolo Bonzini <pbonzini@...hat.com>,
	'Juan Quintela' <quintela@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:	"Zhang, Yang Z" <yang.z.zhang@...el.com>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>
Subject: RE: about the time consuming kvm_vcpu_ioctl issue in rhel kernel

Please Ignore the following message  in the brace
{ The synchronize_rcu() is a time consuming operation,  the unpstream kernel
 still have some issue, the KVM_RUN ioctl will take more then 10ms when
 resume the VM after migration. }

The upstream kernel does not have such issue, only the rhel kernel has. Forgive my neglect. 

Liang


> 
> 
> > -----Original Message-----
> > From: Li, Liang Z
> > Sent: Thursday, August 06, 2015 11:47 AM
> > To: 'Paolo Bonzini'; 'Juan Quintela'; linux-kernel@...r.kernel.org
> > Cc: Zhang, Yang Z; kvm@...r.kernel.org
> > Subject: about the time consuming kvm_vcpu_ioctl issue in rhel kernel
> >
> > Hi Paolo & Juan,
> >
> > I found some of the kvm_vcpu_ioctl operation takes about more than
> > 10ms with the 3.10.0-229.el7.x86_64 kernel, which prolong the VM
> > service downtime when doing live migration about 20~30ms.
> > This happened when doing the KVM_KVMCLOCK_CTRL ioctl. It's worse if
> > more VCPUs used by guest(4VPUs in my test). The upstream kernel does
> > not have this issue because of the patch 7a72f7a140bfd3,  maybe this
> > patch should be backported to the el7 kernel.
> >
> > Liang
--
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/