Hi Reinette,
On 8/15/23 17:50, Reinette Chatre wrote:
> Hi Babu,
>
> Please do note that the subject is no longer accurate.
Changing to
x86/resctrl: Move default group file creation during mount
>
> On 8/11/2023 1:10 PM, Babu Moger wrote:
>> The resctrl default control group is created during kernel init time.
>> If the new files are to be added to the default group based on the mount
>> option, then each file needs to be created separately and call
>> kernfs_activate() again.
>>
>> This can be avoided if all the files are created during the mount and
>> destroyed during the umount. So, move the default group creation
>> in rdt_get_tree() and removal in rdt_kill_sb().
>
> How about a slight rewording (please feel free to change):
>
> The default resource group and its files are created during kernel
> init time. Upcoming changes will make some resctrl files optional
> based on a mount parameter. If optional files are to be added to the
> default group based on the mount option, then each new file needs to
> be created separately and call kernfs_activate() again.
>
> Create all files of the default resource group during resctrl
> mount, destroyed during unmount, to avoid scattering resctrl
> file addition across two separate code flows.
Sure. Looks good. thanks
>
>
>>
>> Suggested-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>> ---
>> arch/x86/kernel/cpu/resctrl/internal.h | 1 +
>> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 50 +++++++++++++++++---------------
>> 2 files changed, 27 insertions(+), 24 deletions(-)
>>
>> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
>> index 37800724e002..2bd92c0c3b0c 100644
>> --- a/arch/x86/kernel/cpu/resctrl/internal.h
>> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
>> @@ -602,5 +602,6 @@ void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
>> void __init thread_throttle_mode_init(void);
>> void __init mbm_config_rftype_init(const char *config);
>> void rdt_staged_configs_clear(void);
>> +int rdtgroup_setup_root(struct rdt_fs_context *ctx);
>>
>> #endif /* _ASM_X86_RESCTRL_INTERNAL_H */
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index 0805fac04401..a7453c93bad4 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -2521,10 +2521,14 @@ static int rdt_get_tree(struct fs_context *fc)
>> goto out;
>> }
>>
>> - ret = rdt_enable_ctx(ctx);
>> + ret = rdtgroup_setup_root(ctx);
>> if (ret)
>> goto out;
>>
>> + ret = rdt_enable_ctx(ctx);
>> + if (ret)
>> + goto out_root;
>> +
>> ret = schemata_list_create();
>> if (ret) {
>> schemata_list_destroy();
>> @@ -2533,6 +2537,12 @@ static int rdt_get_tree(struct fs_context *fc)
>>
>> closid_init();
>>
>> + ret = rdtgroup_add_files(rdtgroup_default.kn, RFTYPE_CTRL_BASE);
>> + if (ret)
>> + goto out_schemata_free;
>> +
>> + kernfs_activate(rdtgroup_default.kn);
>> +
>> ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
>> if (ret < 0)
>> goto out_schemata_free;
>> @@ -2589,6 +2599,8 @@ static int rdt_get_tree(struct fs_context *fc)
>> schemata_list_destroy();
>> out_ctx:
>> rdt_disable_ctx(ctx);
>> +out_root:
>> + kernfs_destroy_root(rdt_root);
>
> Please ensure that all rdtgroup_setup_root() cleanup is done
> here. It seems to me that rdtgroup_default.kn can be left pointing
> to freed memory. Since this cleanup is done multiple places (here
> and rdt_kill_sb()) it may help to create a helper.
Ok. Sure. Will do.
--
Thanks
Babu Moger
