Will, On Tue, Nov 13, 2007 at 01:33:55PM -0500, William Cohen wrote: > > The oprofile module can setup a handler for PMU interrupts. This is done in > archi/x86/oprofile/nmi_int:nmi_cpu_setup(). Other modules could do the > same. However, it bumps what ever was using the nmi/pmu off, then restores > nmi/pmu when oprofile is shut down. Maybe the pmu/nmi resource reservation > mechanism should be another self-contained patch. >
Oprofile does not setup the PMU interrupt. It builds on top of the NMI watchdog setup. It uses the register_die() mechanism, if I recall. The low level APIC and gate is setup elsewhere. Perfmon does not use NMI, unless forced to because of the NMI watchdog. > > - we could not support per-thread mode with the kernel module > > approach due to > > link to the context switch code. I do believe per-thread is a key > > value-add > > for performance monitoring. > > The per-thread monitoring is useful to a number of people and many people > want it. The thought was how to break the large perfmon patch into set of > smaller incremental patches. So it isn't whether to have per-thread pmu > virtualization, but rather when/how to get it in. I think we all agree on this. -- -Stephane - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
