Re: aio poll, io_pgetevents and a new in-kernel poll API V3

2018-01-18 Thread Avi Kivity
On 01/18/2018 07:51 PM, Avi Kivity wrote: On 01/18/2018 05:46 PM, Jeff Moyer wrote: FYI, this kernel has issues.  It will boot up, but I don't have networking, and even rebooting doesn't succeed.  I'm looking into it. FWIW, I'm running an older version of this patchset on my desktop

Re: aio poll, io_pgetevents and a new in-kernel poll API V3

2018-01-18 Thread Avi Kivity
On 01/18/2018 05:46 PM, Jeff Moyer wrote: FYI, this kernel has issues. It will boot up, but I don't have networking, and even rebooting doesn't succeed. I'm looking into it. FWIW, I'm running an older version of this patchset on my desktop with no problems so far. -Jeff Christoph

Re: [kvm-devel] [virtio-net][PATCH] Don't arm tx hrtimer with a constant 500us each transmit

2007-12-17 Thread Avi Kivity
Rusty Russell wrote: On Wednesday 12 December 2007 23:54:00 Dor Laor wrote: commit 763769621d271d92204ed27552d75448587c1ac0 Author: Dor Laor [EMAIL PROTECTED] Date: Wed Dec 12 14:52:00 2007 +0200 [virtio-net][PATCH] Don't arm tx hrtimer with a constant 50us each transmit The

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-15 Thread Avi Kivity
Rusty Russell wrote: On Thu, 2007-04-12 at 06:32 +0300, Avi Kivity wrote: I hadn't considered an always-blocking (or unbuffered) networking API. It's very counter to current APIs, but does make sense with things like syslets. Without syslets, I don't think it's very useful as you need

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-11 Thread Avi Kivity
Rusty Russell wrote: On Wed, 2007-04-11 at 07:26 +0300, Avi Kivity wrote: Nope. Being async is critical for copyless networking: - in the transmit path, so need to stop the sender (guest) from touching the memory until it's on the wire. This means 100% of packets sent will be blocked

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-10 Thread Avi Kivity
Evgeniy Polyakov wrote: On Mon, Apr 09, 2007 at 04:38:18PM +0300, Avi Kivity ([EMAIL PROTECTED]) wrote: But I don't get this we can enhance the kernel but not userspace vibe 8( I've been waiting for network aio since ~2003. If it arrives in the next few days, I'm all

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-10 Thread Avi Kivity
Evgeniy Polyakov wrote: But it looks from this discussion, that it will not prevent from changing in-kernel driver - place a hook into skb allocation path and allocate data from opposing memory - get pages from another side and put them into fragments, then copy headers into skb-data.

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-10 Thread Avi Kivity
Evgeniy Polyakov wrote: This is what Xen does. It is actually less performant than copying, IIRC. The problem with flipping pages around is that physical addresses are cached both in the kvm mmu and in the on-chip tlbs, necessitating expensive page table walks and tlb invalidation IPIs.

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-10 Thread Avi Kivity
Evgeniy Polyakov wrote: On Tue, Apr 10, 2007 at 03:17:45PM +0300, Avi Kivity ([EMAIL PROTECTED]) wrote: Check a link please in case we are talking about different ideas: http://marc.info/?l=linux-netdevm=112262743505711w=2 I don't really understand what you're testing

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-10 Thread Avi Kivity
Rusty Russell wrote: On Mon, 2007-04-09 at 16:38 +0300, Avi Kivity wrote: Moreover, some things just don't lend themselves to a userspace abstraction. If we want to expose tso (tcp segmentation offload), we can easily do so with a kernel driver since the kernel interfaces are all tso

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-09 Thread Avi Kivity
Rusty Russell wrote: On Sun, 2007-04-08 at 08:36 +0300, Avi Kivity wrote: Rusty Russell wrote: Hi Avi, I don't think you've thought about this very hard. The receive copy is completely independent with whether the packet is going to the guest via a kernel driver or via

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-09 Thread Avi Kivity
Rusty Russell wrote: On Mon, 2007-04-09 at 10:10 +0300, Avi Kivity wrote: Rusty Russell wrote: I'm a little puzzled by your response. Hmm... lguest's userspace network frontend does exactly as many copies as Ingo's in-host-kernel code. One from the Guest, one

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-07 Thread Avi Kivity
Rusty Russell wrote: On Thu, 2007-04-05 at 10:17 +0300, Avi Kivity wrote: Rusty Russell wrote: You didn't quote Anthony's point about it's more about there not being good enough userspace interfaces to do network IO. It's easier to write a kernel-space network driver, but it's

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-05 Thread Avi Kivity
Ingo Molnar wrote: so right now the only option for a clean codebase is the KVM in-kernel code. I strongly disagree with this. Bad code in userspace is not an excuse for shoving stuff into the kernel, where maintaining it is much more expensive, and the cause of a mistake can be system

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-05 Thread Avi Kivity
Ingo Molnar wrote: * Avi Kivity [EMAIL PROTECTED] wrote: so right now the only option for a clean codebase is the KVM in-kernel code. I strongly disagree with this. are you disagreeing with my statement that the KVM kernel-side code is the only clean codebase here? To me

Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work

2007-04-05 Thread Avi Kivity
Rusty Russell wrote: You didn't quote Anthony's point about it's more about there not being good enough userspace interfaces to do network IO. It's easier to write a kernel-space network driver, but it's not obviously the right thing to do until we can show that an efficient packet-level

Re: [3/4] kevent: AIO, aio_sendfile() implementation.

2006-07-26 Thread Avi Kivity
David Miller wrote: From: Christoph Hellwig [EMAIL PROTECTED] Date: Wed, 26 Jul 2006 11:04:31 +0100 And to be honest, I don't think adding all this code is acceptable if it can't replace the existing aio code while keeping the interface. So while you interface looks pretty sane the

Re: possible recursive locking in ATM layer

2006-07-05 Thread Avi Kivity
Arjan van de Ven wrote: From: Arjan van de Ven [EMAIL PROTECTED] Linux version 2.6.17-git22 ([EMAIL PROTECTED]) (gcc version 4.0.3 (Ubuntu 4.0.3-1ubuntu5)) #20 PREEMPT Tue Jul 4 10:35:04 CEST 2006 [ 2381.598609] = [ 2381.619314] [ INFO:

Re: Van Jacobson's net channels and real-time

2006-04-23 Thread Avi Kivity
Ingo Oeser wrote: Hi Jörn, On Saturday, 22. April 2006 13:48, Jörn Engel wrote: Unless I completely misunderstand something, one of the main points of the netchannels if to have *zero* fields written to by both producer and consumer. Hmm, for me the main point was to keep the

Re: [RFC] [PATCH 0/3] ioat: DMA engine support

2005-11-24 Thread Avi Kivity
Andi Kleen wrote: Don't forget that there are benefits of not polluting the cache with the traffic for the incoming skbs. Is that a general benefit outside benchmarks? I would expect most real programs to actually do something with the data - and that usually involves needing it in

Re: [RFC] [PATCH 0/3] ioat: DMA engine support

2005-11-24 Thread Avi Kivity
Andi Kleen wrote: As an example, an NFS server reads some data pages using iSCSI and sends them using NFS/TCP (or vice versa). For TX this can be done zero copy using a sendfile like setup. Yes, or with aio send for anonymous memory. For RX it may help - but my point was