* Re: [RFC] [PATCH] cpu_hotplug on IBM JS20 system [not found] ` <1163453995.5940.11.camel@localhost.localdomain> @ 2006-11-14 13:37 ` Srinivasa Ds 2006-11-14 14:14 ` Srinivasa Ds 2006-11-15 2:58 ` Michael Ellerman 0 siblings, 2 replies; 4+ messages in thread From: Srinivasa Ds @ 2006-11-14 13:37 UTC (permalink / raw) To: Benjamin Herrenschmidt, anton, paulus, linuxppc-dev, ego, Srivatsa Vaddagiri Cc: linux-kernel [-- Attachment #1: Type: text/plain, Size: 1406 bytes --] Hi when I tried to hot plug a cpu on IBM bladecentre JS20 system,it dropped in to xmon. On analyzing the problem,I found out that "self-stop" token is not exported to the OS through rtas(Could be verified by looking in to /proc/device-tree/rtas file). 1:mon> e cpu 0x1: Vector: 700 (Program Check) at [c00000000ff1bab0] pc: c00000000001b144: .rtas_stop_self+0x34/0x70 lr: c0000000000439c0: .pSeries_mach_cpu_die+0x34/0x40 sp: c00000000ff1bd30 msr: 8000000000021032 current = 0xc00000000ff050b0 paca = 0xc0000000005ec500 pid = 0, comm = swapper kernel BUG in rtas_stop_self at arch/powerpc/kernel/rtas.c:829! =========================================== void rtas_stop_self(void) { struct rtas_args *rtas_args = &rtas_stop_self_args; local_irq_disable(); BUG_ON(rtas_args->token == RTAS_UNKNOWN_SERVICE); =================================================== #ifdef CONFIG_HOTPLUG_CPU rtas_stop_self_args.token = rtas_token("stop-self"); #endif /* CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_RTAS_ERROR_LOGGING rtas_last_error_token = rtas_token("rtas-last-error"); =================================================== Since we are not supported by hardware for cpu hotplug. I have developed the patch which will disable cpu hotplug on IBM bladecentre JS20. Please let me know your comments on this please. Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> [-- Attachment #2: cpu_hotplug.fix --] [-- Type: text/plain, Size: 3741 bytes --] arch/powerpc/kernel/rtas.c | 3 +++ include/linux/cpu.h | 4 ++++ kernel/cpu.c | 24 ++++++++++++++++++++++-- 3 files changed, 29 insertions(+), 2 deletions(-) Index: linux-2.6.19-rc5/arch/powerpc/kernel/rtas.c =================================================================== --- linux-2.6.19-rc5.orig/arch/powerpc/kernel/rtas.c 2006-11-08 07:54:20.000000000 +0530 +++ linux-2.6.19-rc5/arch/powerpc/kernel/rtas.c 2006-11-14 15:59:58.000000000 +0530 @@ -19,6 +19,7 @@ #include <linux/init.h> #include <linux/capability.h> #include <linux/delay.h> +#include <linux/cpu.h> #include <asm/prom.h> #include <asm/rtas.h> @@ -881,6 +882,8 @@ #ifdef CONFIG_HOTPLUG_CPU rtas_stop_self_args.token = rtas_token("stop-self"); + if(rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE) + disable_cpu_hotplug_perm(); #endif /* CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_RTAS_ERROR_LOGGING rtas_last_error_token = rtas_token("rtas-last-error"); Index: linux-2.6.19-rc5/kernel/cpu.c =================================================================== --- linux-2.6.19-rc5.orig/kernel/cpu.c 2006-11-08 07:54:20.000000000 +0530 +++ linux-2.6.19-rc5/kernel/cpu.c 2006-11-14 16:06:17.000000000 +0530 @@ -63,6 +63,18 @@ } EXPORT_SYMBOL_GPL(unlock_cpu_hotplug); +void disable_cpu_hotplug_perm(void) +{ + mutex_lock(&cpu_add_remove_lock); + cpu_hotplug_disabled = PERM_DISABLED_CPU_HOTPLUG; + mutex_unlock(&cpu_add_remove_lock); +} + +static int is_cpu_hotplug_perm_disabled() +{ + return cpu_hotplug_disabled == PERM_DISABLED_CPU_HOTPLUG; +} + #endif /* CONFIG_HOTPLUG_CPU */ /* Need to know about CPUs going up/down? */ @@ -193,7 +205,7 @@ int err = 0; mutex_lock(&cpu_add_remove_lock); - if (cpu_hotplug_disabled) + if (cpu_hotplug_disabled || is_cpu_hotplug_perm_disabled()) err = -EBUSY; else err = _cpu_down(cpu); @@ -244,7 +256,7 @@ int err = 0; mutex_lock(&cpu_add_remove_lock); - if (cpu_hotplug_disabled) + if (cpu_hotplug_disabled || is_cpu_hotplug_perm_disabled()) err = -EBUSY; else err = _cpu_up(cpu); @@ -261,6 +273,10 @@ int cpu, first_cpu, error; mutex_lock(&cpu_add_remove_lock); + if(is_cpu_hotplug_perm_disabled()) { + error = -EBUSY; + goto out; + } first_cpu = first_cpu(cpu_present_map); if (!cpu_online(first_cpu)) { error = _cpu_up(first_cpu); @@ -311,6 +327,10 @@ /* Allow everyone to use the CPU hotplug again */ mutex_lock(&cpu_add_remove_lock); + if(is_cpu_hotplug_perm_disabled()) { + mutex_unlock(&cpu_add_remove_lock); + return; + } cpu_hotplug_disabled = 0; mutex_unlock(&cpu_add_remove_lock); Index: linux-2.6.19-rc5/include/linux/cpu.h =================================================================== --- linux-2.6.19-rc5.orig/include/linux/cpu.h 2006-11-14 15:55:26.000000000 +0530 +++ linux-2.6.19-rc5/include/linux/cpu.h 2006-11-14 16:08:36.000000000 +0530 @@ -31,6 +31,8 @@ struct sys_device sysdev; }; +#define PERM_DISABLED_CPU_HOTPLUG -1 + extern int register_cpu(struct cpu *cpu, int num); extern struct sys_device *get_cpu_sysdev(unsigned cpu); #ifdef CONFIG_HOTPLUG_CPU @@ -68,6 +70,7 @@ /* Stop CPUs going up and down. */ extern void lock_cpu_hotplug(void); extern void unlock_cpu_hotplug(void); +extern void disable_cpu_hotplug_perm(void); #define hotcpu_notifier(fn, pri) { \ static struct notifier_block fn##_nb = \ { .notifier_call = fn, .priority = pri }; \ @@ -80,6 +83,7 @@ #else #define lock_cpu_hotplug() do { } while (0) #define unlock_cpu_hotplug() do { } while (0) +#define disable_cpu_hotplug_perm() do { } while (0) #define lock_cpu_hotplug_interruptible() 0 #define hotcpu_notifier(fn, pri) do { } while (0) #define register_hotcpu_notifier(nb) do { } while (0) ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC] [PATCH] cpu_hotplug on IBM JS20 system 2006-11-14 13:37 ` [RFC] [PATCH] cpu_hotplug on IBM JS20 system Srinivasa Ds @ 2006-11-14 14:14 ` Srinivasa Ds 2006-11-15 2:58 ` Michael Ellerman 1 sibling, 0 replies; 4+ messages in thread From: Srinivasa Ds @ 2006-11-14 14:14 UTC (permalink / raw) To: Srinivasa Ds, Benjamin Herrenschmidt, anton, paulus, linuxppc-dev, ego, Srivatsa Vaddagiri Cc: linux-kernel [-- Attachment #1: Type: text/plain, Size: 345 bytes --] Srinivasa Ds wrote: > > Since we are not supported by hardware for cpu hotplug. I have > developed the patch which will disable cpu hotplug on IBM bladecentre > JS20. Please let me know your comments on this please. > Iam sorry, Just resending the patch after formatting it again. Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> [-- Attachment #2: cpu_hotplug.fix --] [-- Type: text/plain, Size: 3874 bytes --] arch/powerpc/kernel/rtas.c | 3 +++ include/linux/cpu.h | 4 ++++ kernel/cpu.c | 24 ++++++++++++++++++++++-- 3 files changed, 29 insertions(+), 2 deletions(-) Index: linux-2.6.19-rc5/arch/powerpc/kernel/rtas.c =================================================================== --- linux-2.6.19-rc5.orig/arch/powerpc/kernel/rtas.c +++ linux-2.6.19-rc5/arch/powerpc/kernel/rtas.c @@ -19,6 +19,7 @@ #include <linux/init.h> #include <linux/capability.h> #include <linux/delay.h> +#include <linux/cpu.h> #include <asm/prom.h> #include <asm/rtas.h> @@ -881,6 +882,8 @@ void __init rtas_initialize(void) #ifdef CONFIG_HOTPLUG_CPU rtas_stop_self_args.token = rtas_token("stop-self"); + if(rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE) + disable_cpu_hotplug_perm(); #endif /* CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_RTAS_ERROR_LOGGING rtas_last_error_token = rtas_token("rtas-last-error"); Index: linux-2.6.19-rc5/kernel/cpu.c =================================================================== --- linux-2.6.19-rc5.orig/kernel/cpu.c +++ linux-2.6.19-rc5/kernel/cpu.c @@ -63,8 +63,20 @@ void unlock_cpu_hotplug(void) } EXPORT_SYMBOL_GPL(unlock_cpu_hotplug); +void disable_cpu_hotplug_perm(void) +{ + mutex_lock(&cpu_add_remove_lock); + cpu_hotplug_disabled = PERM_DISABLED_CPU_HOTPLUG; + mutex_unlock(&cpu_add_remove_lock); +} + #endif /* CONFIG_HOTPLUG_CPU */ +static int is_cpu_hotplug_perm_disabled() +{ + return cpu_hotplug_disabled == PERM_DISABLED_CPU_HOTPLUG; +} + /* Need to know about CPUs going up/down? */ int __cpuinit register_cpu_notifier(struct notifier_block *nb) { @@ -193,7 +205,7 @@ int cpu_down(unsigned int cpu) int err = 0; mutex_lock(&cpu_add_remove_lock); - if (cpu_hotplug_disabled) + if (cpu_hotplug_disabled || is_cpu_hotplug_perm_disabled()) err = -EBUSY; else err = _cpu_down(cpu); @@ -244,7 +256,7 @@ int __devinit cpu_up(unsigned int cpu) int err = 0; mutex_lock(&cpu_add_remove_lock); - if (cpu_hotplug_disabled) + if (cpu_hotplug_disabled || is_cpu_hotplug_perm_disabled()) err = -EBUSY; else err = _cpu_up(cpu); @@ -261,6 +273,10 @@ int disable_nonboot_cpus(void) int cpu, first_cpu, error; mutex_lock(&cpu_add_remove_lock); + if(is_cpu_hotplug_perm_disabled()) { + error = -EBUSY; + goto out; + } first_cpu = first_cpu(cpu_present_map); if (!cpu_online(first_cpu)) { error = _cpu_up(first_cpu); @@ -311,6 +327,10 @@ void enable_nonboot_cpus(void) /* Allow everyone to use the CPU hotplug again */ mutex_lock(&cpu_add_remove_lock); + if(is_cpu_hotplug_perm_disabled()) { + mutex_unlock(&cpu_add_remove_lock); + return; + } cpu_hotplug_disabled = 0; mutex_unlock(&cpu_add_remove_lock); Index: linux-2.6.19-rc5/include/linux/cpu.h =================================================================== --- linux-2.6.19-rc5.orig/include/linux/cpu.h +++ linux-2.6.19-rc5/include/linux/cpu.h @@ -31,6 +31,8 @@ struct cpu { struct sys_device sysdev; }; +#define PERM_DISABLED_CPU_HOTPLUG -1 + extern int register_cpu(struct cpu *cpu, int num); extern struct sys_device *get_cpu_sysdev(unsigned cpu); #ifdef CONFIG_HOTPLUG_CPU @@ -68,6 +70,7 @@ extern struct sysdev_class cpu_sysdev_cl /* Stop CPUs going up and down. */ extern void lock_cpu_hotplug(void); extern void unlock_cpu_hotplug(void); +extern void disable_cpu_hotplug_perm(void); #define hotcpu_notifier(fn, pri) { \ static struct notifier_block fn##_nb = \ { .notifier_call = fn, .priority = pri }; \ @@ -80,6 +83,7 @@ int cpu_down(unsigned int cpu); #else #define lock_cpu_hotplug() do { } while (0) #define unlock_cpu_hotplug() do { } while (0) +#define disable_cpu_hotplug_perm() do { } while (0) #define lock_cpu_hotplug_interruptible() 0 #define hotcpu_notifier(fn, pri) do { } while (0) #define register_hotcpu_notifier(nb) do { } while (0) ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC] [PATCH] cpu_hotplug on IBM JS20 system 2006-11-14 13:37 ` [RFC] [PATCH] cpu_hotplug on IBM JS20 system Srinivasa Ds 2006-11-14 14:14 ` Srinivasa Ds @ 2006-11-15 2:58 ` Michael Ellerman 2006-11-15 4:50 ` Srinivasa Ds 1 sibling, 1 reply; 4+ messages in thread From: Michael Ellerman @ 2006-11-15 2:58 UTC (permalink / raw) To: Srinivasa Ds; +Cc: ego, anton, linux-kernel, linuxppc-dev, paulus [-- Attachment #1: Type: text/plain, Size: 487 bytes --] On Tue, 2006-11-14 at 19:07 +0530, Srinivasa Ds wrote: > Hi > when I tried to hot plug a cpu on IBM bladecentre JS20 system,it dropped > in to xmon. How did you try to hot plug a cpu? Through sysfs/hmc/somethingelse ? cheers -- Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person [-- Attachment #2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 189 bytes --] ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC] [PATCH] cpu_hotplug on IBM JS20 system 2006-11-15 2:58 ` Michael Ellerman @ 2006-11-15 4:50 ` Srinivasa Ds 0 siblings, 0 replies; 4+ messages in thread From: Srinivasa Ds @ 2006-11-15 4:50 UTC (permalink / raw) To: michael; +Cc: ego, anton, linux-kernel, linuxppc-dev, paulus Michael Ellerman wrote: > On Tue, 2006-11-14 at 19:07 +0530, Srinivasa Ds wrote: > >> Hi >> when I tried to hot plug a cpu on IBM bladecentre JS20 system,it dropped >> in to xmon. >> > > How did you try to hot plug a cpu? Through sysfs/hmc/somethingelse ? > echo 0 > /sys/devices/system/cpu/cpu1/online > cheers > > ^ permalink raw reply [flat|nested] 4+ messages in thread
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2006-11-14 13:37 ` [RFC] [PATCH] cpu_hotplug on IBM JS20 system Srinivasa Ds
2006-11-14 14:14 ` Srinivasa Ds
2006-11-15 2:58 ` Michael Ellerman
2006-11-15 4:50 ` Srinivasa Ds
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