Re: + paravirt-vmi-timer-patches.patch added to -mm tree
Daniel Walker wrote:
On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote:
+
+unsigned long long vmi_sched_clock(void)
+{
+ return read_available_cycles();
+}
+
This sched_clock is likely broken if it's returning something other than
nanoseconds. It looks like cycles, but it's also getting piped through
an ops pointer so I'm not sure what's getting returned here.
Thanks, I'll fix that.
Zach
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Re: + paravirt-vmi-timer-patches.patch added to -mm tree
Daniel Walker wrote: On Sat, 2007-01-06 at 12:37 -0800, Zachary Amsden wrote: There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given that this implementation seems unnecessary. Why do you need another different system to do this? We don't. This was written before the dynamic tick code, and now they need to be merged. Until then, they can safely coexist. So really this can't go upstream till that merge happens. What's preventing you from just directly using NO_HZ without changes? For one thing, the fact that it doesn't account for stolen time. But mostly because going through the regular PIT / APIC timer paths has a lot of overhead. So we need a separate timer device, and weaving this in with the local APIC timer dependency for SMP on i386 requires changes on top of NO_HZ. Zach - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
On Sat, 2007-01-06 at 12:37 -0800, Zachary Amsden wrote: > > > > There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given > > that this implementation seems unnecessary. Why do you need another > > different system to do this? > > > > We don't. This was written before the dynamic tick code, and now they > need to be merged. Until then, they can safely coexist. So really this can't go upstream till that merge happens. What's preventing you from just directly using NO_HZ without changes? Daniel - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
Daniel Walker wrote: On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote: + +config NO_IDLE_HZ + bool + depends on PARAVIRT + default y + help + Switches the regular HZ timer off when the system is going idle. + This helps a hypervisor detect that the Linux system is idle, + reducing the overhead of idle systems. There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given that this implementation seems unnecessary. Why do you need another different system to do this? We don't. This was written before the dynamic tick code, and now they need to be merged. Until then, they can safely coexist. Zach - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote: > + > +config NO_IDLE_HZ > + bool > + depends on PARAVIRT > + default y > + help > + Switches the regular HZ timer off when the system is going > idle. > + This helps a hypervisor detect that the Linux system is > idle, > + reducing the overhead of idle systems. There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given that this implementation seems unnecessary. Why do you need another different system to do this? Daniel - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote:
> +
> +unsigned long long vmi_sched_clock(void)
> +{
> + return read_available_cycles();
> +}
> +
This sched_clock is likely broken if it's returning something other than
nanoseconds. It looks like cycles, but it's also getting piped through
an ops pointer so I'm not sure what's getting returned here.
Daniel
-
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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote:
+
+unsigned long long vmi_sched_clock(void)
+{
+ return read_available_cycles();
+}
+
This sched_clock is likely broken if it's returning something other than
nanoseconds. It looks like cycles, but it's also getting piped through
an ops pointer so I'm not sure what's getting returned here.
Daniel
-
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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote: + +config NO_IDLE_HZ + bool + depends on PARAVIRT + default y + help + Switches the regular HZ timer off when the system is going idle. + This helps a hypervisor detect that the Linux system is idle, + reducing the overhead of idle systems. There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given that this implementation seems unnecessary. Why do you need another different system to do this? Daniel - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
Daniel Walker wrote: On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote: + +config NO_IDLE_HZ + bool + depends on PARAVIRT + default y + help + Switches the regular HZ timer off when the system is going idle. + This helps a hypervisor detect that the Linux system is idle, + reducing the overhead of idle systems. There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given that this implementation seems unnecessary. Why do you need another different system to do this? We don't. This was written before the dynamic tick code, and now they need to be merged. Until then, they can safely coexist. Zach - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
On Sat, 2007-01-06 at 12:37 -0800, Zachary Amsden wrote: There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given that this implementation seems unnecessary. Why do you need another different system to do this? We don't. This was written before the dynamic tick code, and now they need to be merged. Until then, they can safely coexist. So really this can't go upstream till that merge happens. What's preventing you from just directly using NO_HZ without changes? Daniel - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
Daniel Walker wrote: On Sat, 2007-01-06 at 12:37 -0800, Zachary Amsden wrote: There is already a dynamic tick (NO_HZ) system in the -mm tree .. Given that this implementation seems unnecessary. Why do you need another different system to do this? We don't. This was written before the dynamic tick code, and now they need to be merged. Until then, they can safely coexist. So really this can't go upstream till that merge happens. What's preventing you from just directly using NO_HZ without changes? For one thing, the fact that it doesn't account for stolen time. But mostly because going through the regular PIT / APIC timer paths has a lot of overhead. So we need a separate timer device, and weaving this in with the local APIC timer dependency for SMP on i386 requires changes on top of NO_HZ. Zach - 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/
Re: + paravirt-vmi-timer-patches.patch added to -mm tree
Daniel Walker wrote:
On Fri, 2006-12-15 at 14:27 -0800, [EMAIL PROTECTED] wrote:
+
+unsigned long long vmi_sched_clock(void)
+{
+ return read_available_cycles();
+}
+
This sched_clock is likely broken if it's returning something other than
nanoseconds. It looks like cycles, but it's also getting piped through
an ops pointer so I'm not sure what's getting returned here.
Thanks, I'll fix that.
Zach
-
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/
