From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ashok Raj Date: Mon, 07 Jun 2004 14:08:52 +0000 Subject: Re: [lhcs-devel] Re: [RFC] don't create cpu/online sysfs file Message-Id: <20040607070852.A17932@unix-os.sc.intel.com> List-Id: References: <1086390257.24915.132.camel@nighthawk> In-Reply-To: <1086390257.24915.132.camel@nighthawk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Sun, Jun 06, 2004 at 10:05:35PM -0700, Dave Hansen wrote: > I like that patch a lot. It certainly removes any argument about > function names :) > > Can we maybe change the name of the new field a bit? I strategically (?) changed the name to not_removable, so the field name can indicate the purpose as well clearly. Oh well, i changed the field name to no_control, to indicate "not to create" a control file. the "can_remove" when i read it in isolation, seems to indicate "this cpu is removable" and for correcness i think we would change the normal case to set as 1 instead. picky picky picky :-) i added a note in the function doc as well for clarity. Signed-off-by: Ashok Raj D: This file provides ability for caller of register_cpu() to either create D: a control file, or not. This can be handy if a particular platform decides D: that certain CPU's are not removable. Hence would like to not create D: a control file. --- linux-2.6.7-rc2-root/arch/ppc64/kernel/sysfs.c | 10 ++++++++++ linux-2.6.7-rc2-root/drivers/base/cpu.c | 4 +++- linux-2.6.7-rc2-root/include/linux/cpu.h | 1 + 3 files changed, 14 insertions(+), 1 deletion(-) diff -puN include/linux/cpu.h~cpu_control_file include/linux/cpu.h --- linux-2.6.7-rc2/include/linux/cpu.h~cpu_control_file 2004-06-06 12:54:02.319017387 -0700 +++ linux-2.6.7-rc2-root/include/linux/cpu.h 2004-06-07 06:25:44.667732023 -0700 @@ -27,6 +27,7 @@ struct cpu { int node_id; /* The node which contains the CPU */ + int no_control; /* Should the sysfs control file be created? */ struct sys_device sysdev; }; diff -puN drivers/base/cpu.c~cpu_control_file drivers/base/cpu.c --- linux-2.6.7-rc2/drivers/base/cpu.c~cpu_control_file 2004-06-06 12:56:47.349375320 -0700 +++ linux-2.6.7-rc2-root/drivers/base/cpu.c 2004-06-07 07:03:12.624937664 -0700 @@ -58,6 +58,8 @@ static inline void register_cpu_control( /* * register_cpu - Setup a driverfs device for a CPU. + * @cpu - Callers can set the cpu->no_control field to 1, to indicate not to + * generate a control file in sysfs for this CPU. * @num - CPU number to use when creating the device. * * Initialize and register the CPU device. @@ -75,7 +77,7 @@ int __init register_cpu(struct cpu *cpu, error = sysfs_create_link(&root->sysdev.kobj, &cpu->sysdev.kobj, kobject_name(&cpu->sysdev.kobj)); - if (!error) + if (!error && !cpu->no_control) register_cpu_control(cpu); return error; } diff -puN arch/ppc64/kernel/sysfs.c~cpu_control_file arch/ppc64/kernel/sysfs.c --- linux-2.6.7-rc2/arch/ppc64/kernel/sysfs.c~cpu_control_file 2004-06-06 13:12:06.467033408 -0700 +++ linux-2.6.7-rc2-root/arch/ppc64/kernel/sysfs.c 2004-06-07 06:29:35.126834393 -0700 @@ -325,6 +325,16 @@ static int __init topology_init(void) #ifdef CONFIG_NUMA parent = &node_devices[cpu_to_node(cpu)]; #endif + /* + * For now, we just see if the system supports making + * the RTAS calls for CPU hotplug. But, there may be a + * more comprehensive way to do this for an individual + * CPU. For instance, the boot cpu might never be valid + * for hotplugging. + */ + if (systemcfg->platform = PLATFORM_PSERIES_LPAR) + cpu->no_control=1; + register_cpu(c, cpu, parent); register_cpu_pmc(&c->sysdev); _