Re: [Xenomai-core] [PATCH] fix SYSENTER_CS modificaton race (was: [BUG] sep-related oops on 2.6.20)

2007-10-04 Thread Philippe Gerum
On Thu, 2007-09-27 at 09:59 +0200, Jan Kiszka wrote: And here comes the solution: The attached patch fixes a race related to changing MSR_IA32_SYSENTER_CS when user space requested vm86[old]() services (I assume my X-server does so in the scenario above, maybe to call into the BIOS). We

[Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Jan Kiszka
Hi all, after a really long search I'm now quite sure to have found the reason for the lockups I'm seeing over 2.6.22-i386. I'm yet struggling to understand why this issue is not visible over 2.6.19 and .20 for me, but maybe it is just far less likely there. Here is a short write-up of the

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Philippe Gerum
On Thu, 2007-10-04 at 11:14 +0200, Jan Kiszka wrote: Hi all, after a really long search I'm now quite sure to have found the reason for the lockups I'm seeing over 2.6.22-i386. I'm yet struggling to understand why this issue is not visible over 2.6.19 and .20 for me, but maybe it is just

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Jan Kiszka
Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority inversion: a high-prio domains executes when a fasteoi-IRQ arrives for a low-prio domain. This will now block all IRQs until the low-prio

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Philippe Gerum
On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority inversion: a high-prio domains executes when a fasteoi-IRQ arrives for a low-prio domain. This will now block all IRQs until the low-prio domain was able to

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Philippe Gerum
On Thu, 2007-10-04 at 14:42 +0200, Jan Kiszka wrote: Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority inversion: a high-prio domains executes when a fasteoi-IRQ arrives for a low-prio

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Jan Kiszka
Philippe Gerum wrote: On Thu, 2007-10-04 at 14:42 +0200, Jan Kiszka wrote: Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority inversion: a high-prio domains executes when a fasteoi-IRQ

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Jan Kiszka
Philippe Gerum wrote: On Thu, 2007-10-04 at 16:06 +0200, Jan Kiszka wrote: Philippe Gerum wrote: On Thu, 2007-10-04 at 14:42 +0200, Jan Kiszka wrote: Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Philippe Gerum
On Thu, 2007-10-04 at 16:06 +0200, Jan Kiszka wrote: Philippe Gerum wrote: On Thu, 2007-10-04 at 14:42 +0200, Jan Kiszka wrote: Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Jan Kiszka
Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority inversion: a high-prio domains executes when a fasteoi-IRQ arrives for a low-prio domain. This will now block all IRQs until the low-prio

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Jan Kiszka
Jan Kiszka wrote: Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority inversion: a high-prio domains executes when a fasteoi-IRQ arrives for a low-prio domain. This will now block all IRQs

Re: [Xenomai-core] [BUG] IO-APIC stall due to broken fasteoi handling

2007-10-04 Thread Gilles Chanteperdrix
Philippe Gerum wrote: On Thu, 2007-10-04 at 11:34 +0200, Philippe Gerum wrote: Well, this trace also reveals a second bug that can cause nasty priority inversion: a high-prio domains executes when a fasteoi-IRQ arrives for a low-prio domain. This will now block all IRQs until the