Re: [PATCH] fix up perfmon to build on -mm

[Stephane Eranian <eranian@hpl.hp.com>]

Greg,

Perfmon sysfs document has been updated following your adivce.
you can check out in my perfmon tree  the following commit:

	e83278f879e52ecee025effe9ad509fd51e4a516

Thanks.

On Tue, Nov 06, 2007 at 04:34:54PM -0800, Greg KH wrote:
> Here's a patch against my current tree that gets the perfmon code
> building and hopefully working.
> 
> Note, it needs the kobject_create_and_register() patch which is in my
> tree, but I do not think it made it to -mm yet.  The next -mm cycle
> should have it.
> 
> Also, the sysfs usage in the perfmon code is quite strange and not
> documented at all.  Yes, there is a little bit in the documentation
> about what a few of the files do, but there are _way_ more files and
> even directories being created under /sys/kernel/perfmon/ that are not
> documented at all here.
> 
> If you document this stuff, I think I can clean up your sysfs code a
> lot, making things simpler, easier to extend, and easier to understand.
> But as it is, I don't want to break anything as it's totally unknown how
> this stuff is supposed to work...
> 
> Hint, use the Documentation/ABI directory to document your sysfs
> interfaces, that is what it is there for...
> 
> thanks,
> 
> greg k-h
> 
> ---------------
> From: Greg Kroah-Hartman <gregkh@suse.de>
> Subject: perfmon: fix up some static kobject usages
> 
> This gets the perfmon code to build properly on the latest -mm tree, as
> well as removing some static kobjects.
> 
> A lot of future kobject cleanups can be done on this code, but the
> documentation for the perfmon sysfs interface is very limited and does
> not describe all of the different files and subdirectories at all.
> 
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
> 
> ---
>  perfmon/perfmon_sysfs.c |   37 +++++++++++++++----------------------
>  1 file changed, 15 insertions(+), 22 deletions(-)
> 
> --- a/perfmon/perfmon_sysfs.c
> +++ b/perfmon/perfmon_sysfs.c
> @@ -76,7 +76,8 @@ EXPORT_SYMBOL(pfm_controls);
>  
>  DECLARE_PER_CPU(struct pfm_stats, pfm_stats);
>  
> -static struct kobject pfm_kernel_kobj, pfm_kernel_fmt_kobj;
> +static struct kobject *pfm_kernel_kobj;
> +static struct kobject *pfm_kernel_fmt_kobj;
>  
>  static void pfm_reset_stats(int cpu)
>  {
> @@ -402,31 +403,23 @@ static struct attribute_group pfm_kernel
>  
>  int __init pfm_init_sysfs(void)
>  {
> -	int ret;
> +	int ret = -ENOMEM;
>  	int i, cpu = -1;
>  
> -	kobject_init(&pfm_kernel_kobj);
> -	kobject_init(&pfm_kernel_fmt_kobj);
> -
> -	pfm_kernel_kobj.parent = &kernel_subsys.kobj;
> -	kobject_set_name(&pfm_kernel_kobj, "perfmon");
> -
> -	pfm_kernel_fmt_kobj.parent = &pfm_kernel_kobj;
> -	kobject_set_name(&pfm_kernel_fmt_kobj, "formats");
> -
> -	ret = kobject_add(&pfm_kernel_kobj);
> -	if (ret) {
> -		PFM_INFO("cannot add kernel object: %d", ret);
> +	pfm_kernel_kobj = kobject_create_and_register("perfmon", kernel_kobj);
> +	if (!pfm_kernel_kobj) {
> +		PFM_INFO("cannot create perfmon kernel object");
>  		goto error;
>  	}
>  
> -	ret = kobject_add(&pfm_kernel_fmt_kobj);
> -	if (ret) {
> -		PFM_INFO("cannot add fmt object: %d", ret);
> +	pfm_kernel_fmt_kobj = kobject_create_and_register("formats",
> +							  pfm_kernel_kobj);
> +	if (!pfm_kernel_fmt_kobj) {
> +		PFM_INFO("cannot add fmt object");
>  		goto error_fmt;
>  	}
>  
> -	ret = sysfs_create_group(&pfm_kernel_kobj, &pfm_kernel_attr_group);
> +	ret = sysfs_create_group(pfm_kernel_kobj, &pfm_kernel_attr_group);
>  	if (ret) {
>  		PFM_INFO("cannot create kernel group");
>  		goto error_group;
> @@ -449,9 +442,9 @@ int __init pfm_init_sysfs(void)
>  	return 0;
>  
>  error_group:
> -	kobject_del(&pfm_kernel_fmt_kobj);
> +	kobject_unregister(pfm_kernel_fmt_kobj);
>  error_fmt:
> -	kobject_del(&pfm_kernel_kobj);
> +	kobject_unregister(pfm_kernel_kobj);
>  
>  	for (i=0; i < cpu; i++)
>  		pfm_sysfs_del_cpu(i);
> @@ -683,7 +676,7 @@ int pfm_sysfs_add_fmt(struct pfm_smpl_fm
>  
>  	kobject_set_name(&fmt->kobj, fmt->fmt_name);
>  	//kobj_set_kset_s(fmt, pfm_fmt_subsys);
> -	fmt->kobj.parent = &pfm_kernel_fmt_kobj;
> +	fmt->kobj.parent = pfm_kernel_fmt_kobj;
>  
>  	ret = kobject_add(&fmt->kobj);
>  	if (ret)
> @@ -861,7 +854,7 @@ int pfm_sysfs_add_pmu(struct pfm_pmu_con
>  	kobject_init(&pmu->kobj);
>  	kobject_set_name(&pmu->kobj, "pmu_desc");
>  	//kobj_set_kset_s(pmu, pfm_pmu_subsys);
> -	pmu->kobj.parent = &pfm_kernel_kobj;
> +	pmu->kobj.parent = pfm_kernel_kobj;
>  
>  	ret = kobject_add(&pmu->kobj);
>  	if (ret)

-- 

-Stephane