Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-28 Thread Avi Kivity
On 08/23/2011 05:10 PM, Jan Kiszka wrote: On 2011-08-23 16:02, Anthony Liguori wrote: > On 08/23/2011 08:02 AM, Jan Kiszka wrote: >> On 2011-08-23 14:40, Anthony Liguori wrote: >>> You should be able to just use an eventfd or pipe. >>> >>> Better yet, we should look at using GThreadPool to re

Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-23 Thread Jan Kiszka
On 2011-08-23 16:02, Anthony Liguori wrote: > On 08/23/2011 08:02 AM, Jan Kiszka wrote: >> On 2011-08-23 14:40, Anthony Liguori wrote: >>> You should be able to just use an eventfd or pipe. >>> >>> Better yet, we should look at using GThreadPool to replace posix-aio-compat. >> >> When interacting w

Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-23 Thread Anthony Liguori
On 08/23/2011 08:02 AM, Jan Kiszka wrote: On 2011-08-23 14:40, Anthony Liguori wrote: You should be able to just use an eventfd or pipe. Better yet, we should look at using GThreadPool to replace posix-aio-compat. When interacting with the thread pool is part of some time-critical path (easil

Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-23 Thread Jan Kiszka
On 2011-08-23 14:40, Anthony Liguori wrote: > On 08/23/2011 06:01 AM, Stefan Hajnoczi wrote: >> On Mon, Aug 22, 2011 at 6:29 PM, Jan Kiszka wrote: >>> On 2011-08-14 06:04, Avi Kivity wrote: In certain circumstances, posix-aio-compat can incur a lot of latency: - threads are created by

Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-23 Thread Anthony Liguori
On 08/23/2011 06:01 AM, Stefan Hajnoczi wrote: On Mon, Aug 22, 2011 at 6:29 PM, Jan Kiszka wrote: On 2011-08-14 06:04, Avi Kivity wrote: In certain circumstances, posix-aio-compat can incur a lot of latency: - threads are created by vcpu threads, so if vcpu affinity is set, aio threads i

Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-23 Thread Stefan Hajnoczi
On Mon, Aug 22, 2011 at 6:29 PM, Jan Kiszka wrote: > On 2011-08-14 06:04, Avi Kivity wrote: >> In certain circumstances, posix-aio-compat can incur a lot of latency: >>  - threads are created by vcpu threads, so if vcpu affinity is set, >>    aio threads inherit vcpu affinity.  This can cause many

Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-22 Thread Jan Kiszka
On 2011-08-14 06:04, Avi Kivity wrote: > In certain circumstances, posix-aio-compat can incur a lot of latency: > - threads are created by vcpu threads, so if vcpu affinity is set, >aio threads inherit vcpu affinity. This can cause many aio threads >to compete for one cpu. > - we can cre

Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-22 Thread Kevin Wolf
Am 14.08.2011 06:04, schrieb Avi Kivity: > In certain circumstances, posix-aio-compat can incur a lot of latency: > - threads are created by vcpu threads, so if vcpu affinity is set, >aio threads inherit vcpu affinity. This can cause many aio threads >to compete for one cpu. > - we can c

[Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

2011-08-13 Thread Avi Kivity
In certain circumstances, posix-aio-compat can incur a lot of latency: - threads are created by vcpu threads, so if vcpu affinity is set, aio threads inherit vcpu affinity. This can cause many aio threads to compete for one cpu. - we can create up to max_threads (64) aio threads in one go;