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

From: Stephane Eranian
Date: Wed Nov 07 2007 - 08:43:20 EST


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@xxxxxxx>
> 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@xxxxxxx>
>
> ---
> 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
-
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