Re: [PATCH 13/14] x86/ticketlock: add slowpath logic

2011-01-20 Thread Jan Beulich
On 19.01.11 at 19:55, Jeremy Fitzhardinge jer...@goop.org wrote: On 01/19/2011 10:39 AM, Srivatsa Vaddagiri wrote: I have tested quite extensively with booting a 16-vcpu guest (on a 16-pcpu host) and running kernel compine (with 32-threads). Without this patch, I had difficulty

[PULL] lguest and virtio.

2011-01-20 Thread Rusty Russell
The following changes since commit 8a335bc631ac9c43675821580c26ebf95a3044ba: Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/scsi-post-merge-2.6 (2011-01-16 15:06:43 -0800) are available in the git repository at:

Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock

2011-01-20 Thread Srivatsa Vaddagiri
On Wed, Jan 19, 2011 at 10:53:52AM -0800, Jeremy Fitzhardinge wrote: The reason for wanting this should be clear I guess, it allows PI. Well, if we can expand the spinlock to include an owner, then all this becomes moot... How so? Having an owner will not eliminate the need for

Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock

2011-01-20 Thread Srivatsa Vaddagiri
On Wed, Jan 19, 2011 at 10:53:52AM -0800, Jeremy Fitzhardinge wrote: I didn't really read the patch, and I totally forgot everything from when I looked at the Xen series, but does the Xen/KVM hypercall interface for this include the vcpu to await the kick from? My guess is not, since the

Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock

2011-01-20 Thread Peter Zijlstra
On Thu, 2011-01-20 at 17:29 +0530, Srivatsa Vaddagiri wrote: If we had a yield-to [1] sort of interface _and_ information on which vcpu owns a lock, then lock-spinners can yield-to the owning vcpu, and then I'd nak it for being stupid ;-) really, yield*() is retarded, never even consider

Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock

2011-01-20 Thread Srivatsa Vaddagiri
On Thu, Jan 20, 2011 at 02:41:46PM +0100, Peter Zijlstra wrote: On Thu, 2011-01-20 at 17:29 +0530, Srivatsa Vaddagiri wrote: If we had a yield-to [1] sort of interface _and_ information on which vcpu owns a lock, then lock-spinners can yield-to the owning vcpu, and then I'd nak it for

Re: [PATCH] change acquire/release_console_sem() to console_lock/unlock()

2011-01-20 Thread Greg KH
On Thu, Jan 20, 2011 at 04:58:13PM +0100, Torben Hohn wrote: the -rt patches change the console_semaphore to console_mutex. so a quite large chunk of the patches changes all acquire/release_console_sem() to acquire/release_console_mutex() Why not just change the functionality of the existing

Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock

2011-01-20 Thread Jeremy Fitzhardinge
On 01/20/2011 03:42 AM, Srivatsa Vaddagiri wrote: On Wed, Jan 19, 2011 at 10:53:52AM -0800, Jeremy Fitzhardinge wrote: The reason for wanting this should be clear I guess, it allows PI. Well, if we can expand the spinlock to include an owner, then all this becomes moot... How so? Having an

Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock

2011-01-20 Thread Jeremy Fitzhardinge
On 01/20/2011 03:59 AM, Srivatsa Vaddagiri wrote: At least in the Xen code, a current owner isn't very useful, because we need the current owner to kick the *next* owner to life at release time, which we can't do without some structure recording which ticket belongs to which cpu. If we had a

Re: Flow Control and Port Mirroring Revisited

2011-01-20 Thread Rick Jones
So it won't be all that simple to implement well, and before we try, I'd like to know whether there are applications that are helped by it. For example, we could try to measure latency at various pps and see whether the backpressure helps. netperf has -b, -w flags which might help these

Re: Flow Control and Port Mirroring Revisited

2011-01-20 Thread Rick Jones
Michael S. Tsirkin wrote: On Tue, Jan 18, 2011 at 11:41:22AM -0800, Rick Jones wrote: PS - the enhanced latency statistics from -j are only available in the omni version of the TCP_RR test. To get that add a --enable-omni to the ./configure - and in this case both netperf and netserver have to

Re: [PATCH] change acquire/release_console_sem() to console_lock/unlock()

2011-01-20 Thread torbenh
On Thu, Jan 20, 2011 at 08:34:48AM -0800, Greg KH wrote: On Thu, Jan 20, 2011 at 04:58:13PM +0100, Torben Hohn wrote: the -rt patches change the console_semaphore to console_mutex. so a quite large chunk of the patches changes all acquire/release_console_sem() to

Re: [PATCH] change acquire/release_console_sem() to console_lock/unlock()

2011-01-20 Thread Andrew Morton
On Thu, 20 Jan 2011 17:55:02 +0100 torbenh torb...@gmx.de wrote: On Thu, Jan 20, 2011 at 08:34:48AM -0800, Greg KH wrote: On Thu, Jan 20, 2011 at 04:58:13PM +0100, Torben Hohn wrote: the -rt patches change the console_semaphore to console_mutex. so a quite large chunk of the patches

Re: Flow Control and Port Mirroring Revisited

2011-01-20 Thread Simon Horman
[ Trimmed Eric from CC list as vger was complaining that it is too long ] On Tue, Jan 18, 2011 at 11:41:22AM -0800, Rick Jones wrote: So it won't be all that simple to implement well, and before we try, I'd like to know whether there are applications that are helped by it. For example, we

Re: Flow Control and Port Mirroring Revisited

2011-01-20 Thread Rick Jones
Simon Horman wrote: [ Trimmed Eric from CC list as vger was complaining that it is too long ] ... I have constructed a test where I run an un-paced UDP_STREAM test in one guest and a paced omni rr test in another guest at the same time. Breifly I get the following results from the omni test..