search for: hotplug_cpu

I am trying to build xen on x86_64 SLES 9 SP2 box this morning and am getting this error: arch/xen/kernel/built-in.o(.text+0x1bd6): In function `__do_suspend'': : undefined reference to `HYPERVISOR_vcpu_pickle'' make[4]: *** [.tmp_vmlinux1] Error 1 make[4]: Leaving directory `/tmp/xen-unstable.hg/linux-2.6.12-xen0'' make[3]: *** [build] Error 2 make[3]: Leaving directory

Is there any real user for this vIRQ? I''m asking because, while debugging a problem that required to add some printk()s that could temporarily issue at a high rate, I ran into the situation that this extra output prevented guest/dom0 boot from making any progress. As I then realized this was due to the tasklet_schedule() called from inside the console handling code, which resulted in

Is there any real user for this vIRQ? I''m asking because, while debugging a problem that required to add some printk()s that could temporarily issue at a high rate, I ran into the situation that this extra output prevented guest/dom0 boot from making any progress. As I then realized this was due to the tasklet_schedule() called from inside the console handling code, which resulted in

...arch/x86/xen/smp.c | 8 -------- 1 files changed, 0 insertions(+), 8 deletions(-) diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 09a7199..602d6b7 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -417,14 +417,6 @@ static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */ { play_dead_common(); HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL); - cpu_bringup(); - /* - * Balance out the preempt calls - as we are running in cpu_idle - * loop which has been called at bootup from cpu_bringup_and_idle. - * The cpucpu_bringup_and_idle called cpu_bringup...

...arch/x86/xen/smp.c | 8 -------- 1 files changed, 0 insertions(+), 8 deletions(-) diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 09a7199..602d6b7 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -417,14 +417,6 @@ static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */ { play_dead_common(); HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL); - cpu_bringup(); - /* - * Balance out the preempt calls - as we are running in cpu_idle - * loop which has been called at bootup from cpu_bringup_and_idle. - * The cpucpu_bringup_and_idle called cpu_bringup...

..._USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF if PPC64 + select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS + select ARCH_USE_QUEUED_SPINLOCKS if PPC_QUEUED_SPINLOCKS select ARCH_WANT_IPC_PARSE_VERSION select ARCH_WEAK_RELEASE_ACQUIRE select BINFMT_ELF @@ -490,6 +492,17 @@ config HOTPLUG_CPU Say N if you are unsure. +config PPC_QUEUED_SPINLOCKS + bool "Queued spinlocks" + depends on SMP + default "y" if PPC_BOOK3S_64 + help + Say Y here to use to use queued spinlocks which are more complex + but give better salability and fairness on large SMP and NUMA +...

..._USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF if PPC64 + select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS + select ARCH_USE_QUEUED_SPINLOCKS if PPC_QUEUED_SPINLOCKS select ARCH_WANT_IPC_PARSE_VERSION select ARCH_WEAK_RELEASE_ACQUIRE select BINFMT_ELF @@ -492,6 +494,17 @@ config HOTPLUG_CPU Say N if you are unsure. +config PPC_QUEUED_SPINLOCKS + bool "Queued spinlocks" + depends on SMP + default "y" if PPC_BOOK3S_64 + help + Say Y here to use to use queued spinlocks which are more complex + but give better salability and fairness on large SMP and NUMA +...

...xen/smp.c @@ -17,6 +17,7 @@ #include <linux/slab.h> #include <linux/smp.h> #include <linux/irq_work.h> +#include <linux/tick.h> #include <asm/paravirt.h> #include <asm/desc.h> @@ -447,6 +448,13 @@ static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */ play_dead_common(); HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL); cpu_bringup(); + /* + * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down) + * clears certain data that the cpu_idle loop (which called us + * and that we return from) expects. The only way to get...

...t; include/asm-generic/qspinlock.h | 2 ++ Who's ack do we need for that part? > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 24ac85c868db..17663ea57697 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -492,6 +494,17 @@ config HOTPLUG_CPU > > Say N if you are unsure. > > +config PPC_QUEUED_SPINLOCKS > + bool "Queued spinlocks" > + depends on SMP > + default "y" if PPC_BOOK3S_64 Not sure about default y? At least until we've got a better idea of the perf impact on a range of small...

hi, i386 vcpu hotplug seems to work reliably but x86_64 does not and i think i have discovered why. in x86-64, a cpu within a domu can be removed with vcpu-set but subsequent calls do nothing. after xenwatch_thread grabs the event triggered by the write to the store, it calls the registered handler and never comes back. eventually, __cpu_die in drivers/xen/core/smpboot.c spins while waiting

This patch adds new control messages for vcpu hotplug events. Via the xm vcpu_hotplug sub-program, VCPUS in domains can be enabled/disabled when CONFIG_HOTPLUG_CPU is enabled in the target domain''s kernel. Currently there is nothing that tracks whether a VCPU is up or down. My previous [1]patch added a new per-VCPU flag (VCPUF_down) which could be used to keep track of which VCPUS are up and down. Right now, there isn''t a hypercall that re...

...l.com> Index: head-2007-02-27/arch/i386/Kconfig =================================================================== --- head-2007-02-27.orig/arch/i386/Kconfig 2007-03-05 10:00:18.000000000 +0100 +++ head-2007-02-27/arch/i386/Kconfig 2007-02-27 16:27:37.000000000 +0100 @@ -819,7 +819,6 @@ config HOTPLUG_CPU config COMPAT_VDSO bool "Compat VDSO support" - depends on !X86_XEN default y help Map the VDSO to the predictable old-style address too. Index: head-2007-02-27/arch/i386/kernel/Makefile =================================================================== --- head-2007-02-27.o...

...l.com> Index: head-2007-02-27/arch/i386/Kconfig =================================================================== --- head-2007-02-27.orig/arch/i386/Kconfig 2007-03-05 10:00:18.000000000 +0100 +++ head-2007-02-27/arch/i386/Kconfig 2007-02-27 16:27:37.000000000 +0100 @@ -819,7 +819,6 @@ config HOTPLUG_CPU config COMPAT_VDSO bool "Compat VDSO support" - depends on !X86_XEN default y help Map the VDSO to the predictable old-style address too. Index: head-2007-02-27/arch/i386/kernel/Makefile =================================================================== --- head-2007-02-27.o...

...l.com> Index: head-2007-02-27/arch/i386/Kconfig =================================================================== --- head-2007-02-27.orig/arch/i386/Kconfig 2007-03-05 10:00:18.000000000 +0100 +++ head-2007-02-27/arch/i386/Kconfig 2007-02-27 16:27:37.000000000 +0100 @@ -819,7 +819,6 @@ config HOTPLUG_CPU config COMPAT_VDSO bool "Compat VDSO support" - depends on !X86_XEN default y help Map the VDSO to the predictable old-style address too. Index: head-2007-02-27/arch/i386/kernel/Makefile =================================================================== --- head-2007-02-27.o...

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt

From: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> This patch aims to enable qspinlock on PPC. And on pseries platform, it also support paravirt qspinlock. Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> --- arch/powerpc/include/asm/qspinlock.h | 37 +++++++++++++++ arch/powerpc/include/asm/qspinlock_paravirt.h | 36 +++++++++++++++

From: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> This patch aims to enable qspinlock on PPC. And on pseries platform, it also support paravirt qspinlock. Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> --- arch/powerpc/include/asm/qspinlock.h | 37 +++++++++++++++ arch/powerpc/include/asm/qspinlock_paravirt.h | 36 +++++++++++++++

v2 is updated to account for feedback from Will, Peter, and Waiman (thank you), and trims off a couple of RFC and unrelated patches. Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued

Updated with everybody's feedback (thanks all), and more performance results. What I've found is I might have been measuring the worst load point for the paravirt case, and by looking at a range of loads it's clear that queued spinlocks are overall better even on PV, doubly so when you look at the generally much improved worst case latencies. I have defaulted it to N even though