Re: [Xenomai-core] Long execution time inside __ipipe_unstall_iret_root()

2007-11-12 Thread Jan Kiszka
Jeroen Van den Keybus wrote: I have a setup which apparently suffers from long interrupt-disabled sections during heavy load (make -j16 of a kernel). I have instrumented the __ipipe_unstall_iret_root() function with the tracer as follows: asmlinkage void __ipipe_unstall_iret_root(struct

Re: [Xenomai-core] Long execution time inside __ipipe_unstall_iret_root()

2007-11-12 Thread Jeroen Van den Keybus
So, unless the IRQ below should have been raised much earlier, there is no issue here. The point is: I actually do have interrupts (not the IPI that is visible here) that are being withheld (on average 80 us late) during this period. On this particular setup, I have seen numbers exceeding 300

Re: [Xenomai-core] Long execution time inside __ipipe_unstall_iret_root()

2007-11-12 Thread Jan Kiszka
Jeroen Van den Keybus wrote: So, unless the IRQ below should have been raised much earlier, there is no issue here. The point is: I actually do have interrupts (not the IPI that is visible here) that are being withheld (on average 80 us late) during this period. On this particular setup,

Re: [Xenomai-core] Long execution time inside __ipipe_unstall_iret_root()

2007-11-12 Thread Jan Kiszka
[Save the CCs!] Jeroen Van den Keybus wrote: Indeed, 300 us are too long. Maybe long DMA bursts on your PCI bus? Can you exclude certain devices from your load to check for this (no hardisk load e.g., use nfs instead, then no network load, etc.)? I already tried setting PCI latency timers

Re: [Xenomai-core] Long execution time inside __ipipe_unstall_iret_root()

2007-11-12 Thread Jeroen Van den Keybus
Ouch, this shouldn't be allowed in user space! WBINVD is a privileged instruction. Do we leak privileges to user land??? Please check if your execution mode (privilege ring) is correct there. No, I rather meant a kernel-mode program that was controlled from the user space. Sorry for

Re: [Xenomai-core] Long execution time inside __ipipe_unstall_iret_root()

2007-11-12 Thread Jan Kiszka
Jeroen Van den Keybus wrote: Ouch, this shouldn't be allowed in user space! WBINVD is a privileged instruction. Do we leak privileges to user land??? Please check if your execution mode (privilege ring) is correct there. No, I rather meant a kernel-mode program that was controlled from the