Re: [PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-12-07 Thread Steven Rostedt
On Thu, 7 Dec 2017 01:27:03 + "Su, David W" wrote: > >And spin_lock() turns into a mutex in PREEMPT_RT, which means it can > >sleep. You can't sleep in hard interrupt context. This will eventually > >crash the kernel. > > Steve, thanks for your review and comment. >

Re: [PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-12-07 Thread Steven Rostedt
On Thu, 7 Dec 2017 01:27:03 + "Su, David W" wrote: > >And spin_lock() turns into a mutex in PREEMPT_RT, which means it can > >sleep. You can't sleep in hard interrupt context. This will eventually > >crash the kernel. > > Steve, thanks for your review and comment. > > I can think of 2

RE: [PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-12-06 Thread Su, David W
From: Steven Rostedt [mailto:rost...@goodmis.org] Sent: Thursday, November 30, 2017 6:09 PM > >On Thu, 30 Nov 2017 17:05:35 -0800 >David Su wrote: > >> Setting MSI/MSI-X ISR to be non-threaded will result in shorter and more >> deterministic IRQ delivery latencies to VFIO

RE: [PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-12-06 Thread Su, David W
From: Steven Rostedt [mailto:rost...@goodmis.org] Sent: Thursday, November 30, 2017 6:09 PM > >On Thu, 30 Nov 2017 17:05:35 -0800 >David Su wrote: > >> Setting MSI/MSI-X ISR to be non-threaded will result in shorter and more >> deterministic IRQ delivery latencies to VFIO applications, because >>

Re: [PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-11-30 Thread Steven Rostedt
On Thu, 30 Nov 2017 17:05:35 -0800 David Su wrote: > Setting MSI/MSI-X ISR to be non-threaded will result in shorter and more > deterministic IRQ delivery latencies to VFIO applications, because > context switches to the ISR thread are eliminated. This is important > for

Re: [PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-11-30 Thread Steven Rostedt
On Thu, 30 Nov 2017 17:05:35 -0800 David Su wrote: > Setting MSI/MSI-X ISR to be non-threaded will result in shorter and more > deterministic IRQ delivery latencies to VFIO applications, because > context switches to the ISR thread are eliminated. This is important > for applications with low

[PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-11-30 Thread David Su
Setting MSI/MSI-X ISR to be non-threaded will result in shorter and more deterministic IRQ delivery latencies to VFIO applications, because context switches to the ISR thread are eliminated. This is important for applications with low latency requirement running in virtual machines on RT Linux

[PATCH RT] vfio-pci: Set MSI/MSI-X ISR to non-threaded

2017-11-30 Thread David Su
Setting MSI/MSI-X ISR to be non-threaded will result in shorter and more deterministic IRQ delivery latencies to VFIO applications, because context switches to the ISR thread are eliminated. This is important for applications with low latency requirement running in virtual machines on RT Linux