diff mbox series

[v7,03/24] x86/resctrl: Create helper for RMID allocation and mondata dir creation

Message ID 20231025180345.28061-4-james.morse@arm.com
State New
Headers
Series x86/resctrl: monitored closid+rmid together, separate arch/fs locking |

Commit Message

James Morse Oct. 25, 2023, 6:03 p.m. UTC 
  When monitoring is supported, each monitor and control group is allocated
an RMID. For control groups, rdtgroup_mkdir_ctrl_mon() later goes on to
allocate the CLOSID.

MPAM's equivalent of RMID are not an independent number, so can't be
allocated until the CLOSID is known. An RMID allocation for one CLOSID
may fail, whereas another may succeed depending on how many monitor
groups a control group has.

The RMID allocation needs to move to be after the CLOSID has been
allocated.

Move the RMID allocation and mondata dir creation to a helper, this
makes a subsequent change easier to read.

Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: James Morse <james.morse@arm.com>
---
Changes since v4:
 * Fixed typo in commit message, moved some words around.

No changes since v6
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 42 +++++++++++++++++---------
 1 file changed, 27 insertions(+), 15 deletions(-)

Comments

Reinette Chatre Nov. 9, 2023, 5:40 p.m. UTC | #1 
Hi James,

On 10/25/2023 11:03 AM, James Morse wrote:
> When monitoring is supported, each monitor and control group is allocated
> an RMID. For control groups, rdtgroup_mkdir_ctrl_mon() later goes on to
> allocate the CLOSID.
> 
> MPAM's equivalent of RMID are not an independent number, so can't be
> allocated until the CLOSID is known. An RMID allocation for one CLOSID
> may fail, whereas another may succeed depending on how many monitor
> groups a control group has.
> 
> The RMID allocation needs to move to be after the CLOSID has been
> allocated.
> 
> Move the RMID allocation and mondata dir creation to a helper, this
> makes a subsequent change easier to read.

Boris recently reminded us that text like "subsequent change" loses meaning
once the commit forms part of the kernel. This term is used in a couple of
places in this series. Please review all changelogs to remove this term
to avoid another re-spin.

For reference:
https://lore.kernel.org/lkml/20231009171918.GPZSQ2Frs%2Fqp129wsP@fat_crate.local/

> 
> Tested-by: Peter Newman <peternewman@google.com>
> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
> Signed-off-by: James Morse <james.morse@arm.com>

Please have tags follow "Ordering of commit tags" in
Documentation/process/maintainer-tip.rst (author SOB
appears before the Tested-by/Reviewed-by/Acked-by).

Reinette
Moger, Babu Nov. 9, 2023, 8:28 p.m. UTC | #2 
Hi James,

On 10/25/23 13:03, James Morse wrote:
> When monitoring is supported, each monitor and control group is allocated
> an RMID. For control groups, rdtgroup_mkdir_ctrl_mon() later goes on to
> allocate the CLOSID.
> 
> MPAM's equivalent of RMID are not an independent number, so can't be
> allocated until the CLOSID is known. An RMID allocation for one CLOSID
> may fail, whereas another may succeed depending on how many monitor
> groups a control group has.
> 
> The RMID allocation needs to move to be after the CLOSID has been
> allocated.
> 
> Move the RMID allocation and mondata dir creation to a helper, this
> makes a subsequent change easier to read.
> 
> Tested-by: Peter Newman <peternewman@google.com>
> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
> Signed-off-by: James Morse <james.morse@arm.com>

Reviewed-by: Babu Moger <babu.moger@amd.com>

> ---
> Changes since v4:
>  * Fixed typo in commit message, moved some words around.
> 
> No changes since v6
> ---
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c | 42 +++++++++++++++++---------
>  1 file changed, 27 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 69a1de92384a..1eb3a3075093 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -3293,6 +3293,30 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
>  	return ret;
>  }
>  
> +static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
> +{
> +	int ret;
> +
> +	if (!rdt_mon_capable)
> +		return 0;
> +
> +	ret = alloc_rmid();
> +	if (ret < 0) {
> +		rdt_last_cmd_puts("Out of RMIDs\n");
> +		return ret;
> +	}
> +	rdtgrp->mon.rmid = ret;
> +
> +	ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
> +	if (ret) {
> +		rdt_last_cmd_puts("kernfs subdir error\n");
> +		free_rmid(rdtgrp->mon.rmid);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
>  			     const char *name, umode_t mode,
>  			     enum rdt_group_type rtype, struct rdtgroup **r)
> @@ -3365,20 +3389,10 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
>  		goto out_destroy;
>  	}
>  
> -	if (rdt_mon_capable) {
> -		ret = alloc_rmid();
> -		if (ret < 0) {
> -			rdt_last_cmd_puts("Out of RMIDs\n");
> -			goto out_destroy;
> -		}
> -		rdtgrp->mon.rmid = ret;
> +	ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
> +	if (ret)
> +		goto out_destroy;
>  
> -		ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
> -		if (ret) {
> -			rdt_last_cmd_puts("kernfs subdir error\n");
> -			goto out_idfree;
> -		}
> -	}
>  	kernfs_activate(kn);
>  
>  	/*
> @@ -3386,8 +3400,6 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
>  	 */
>  	return 0;
>  
> -out_idfree:
> -	free_rmid(rdtgrp->mon.rmid);
>  out_destroy:
>  	kernfs_put(rdtgrp->kn);
>  	kernfs_remove(rdtgrp->kn);
James Morse Dec. 13, 2023, 6:03 p.m. UTC | #3 
Hi Babu,

On 09/11/2023 20:28, Moger, Babu wrote:
> On 10/25/23 13:03, James Morse wrote:
>> When monitoring is supported, each monitor and control group is allocated
>> an RMID. For control groups, rdtgroup_mkdir_ctrl_mon() later goes on to
>> allocate the CLOSID.
>>
>> MPAM's equivalent of RMID are not an independent number, so can't be
>> allocated until the CLOSID is known. An RMID allocation for one CLOSID
>> may fail, whereas another may succeed depending on how many monitor
>> groups a control group has.
>>
>> The RMID allocation needs to move to be after the CLOSID has been
>> allocated.
>>
>> Move the RMID allocation and mondata dir creation to a helper, this
>> makes a subsequent change easier to read.
>>
>> Tested-by: Peter Newman <peternewman@google.com>
>> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
>> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
>> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
>> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
>> Signed-off-by: James Morse <james.morse@arm.com>
> 
> Reviewed-by: Babu Moger <babu.moger@amd.com>

Thanks!


James
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 69a1de92384a..1eb3a3075093 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -3293,6 +3293,30 @@  static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
 	return ret;
 }
 
+static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
+{
+	int ret;
+
+	if (!rdt_mon_capable)
+		return 0;
+
+	ret = alloc_rmid();
+	if (ret < 0) {
+		rdt_last_cmd_puts("Out of RMIDs\n");
+		return ret;
+	}
+	rdtgrp->mon.rmid = ret;
+
+	ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
+	if (ret) {
+		rdt_last_cmd_puts("kernfs subdir error\n");
+		free_rmid(rdtgrp->mon.rmid);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
 			     const char *name, umode_t mode,
 			     enum rdt_group_type rtype, struct rdtgroup **r)
@@ -3365,20 +3389,10 @@  static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
 		goto out_destroy;
 	}
 
-	if (rdt_mon_capable) {
-		ret = alloc_rmid();
-		if (ret < 0) {
-			rdt_last_cmd_puts("Out of RMIDs\n");
-			goto out_destroy;
-		}
-		rdtgrp->mon.rmid = ret;
+	ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
+	if (ret)
+		goto out_destroy;
 
-		ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
-		if (ret) {
-			rdt_last_cmd_puts("kernfs subdir error\n");
-			goto out_idfree;
-		}
-	}
 	kernfs_activate(kn);
 
 	/*
@@ -3386,8 +3400,6 @@  static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
 	 */
 	return 0;
 
-out_idfree:
-	free_rmid(rdtgrp->mon.rmid);
 out_destroy:
 	kernfs_put(rdtgrp->kn);
 	kernfs_remove(rdtgrp->kn);