[PATCH v9 03/24] x86/resctrl: Create helper for RMID allocation and mondata dir creation

James Morse posted 24 patches 1 year, 10 months ago
[PATCH v9 03/24] x86/resctrl: Create helper for RMID allocation and mondata dir creation
Posted by James Morse 1 year, 10 months ago
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.

Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
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>
Reviewed-by: Babu Moger <babu.moger@amd.com>

---
Changes since v4:
 * Fixed typo in commit message, moved some words around.
---
 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 aa24343f1d23..4ea5a871be49 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -3288,6 +3288,30 @@ 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)
@@ -3360,20 +3384,10 @@ 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);
 
 	/*
@@ -3381,8 +3395,6 @@ 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);
-- 
2.39.2

Re: [PATCH v9 03/24] x86/resctrl: Create helper for RMID allocation and mondata dir creation
Posted by David Hildenbrand 1 year, 10 months ago
On 13.02.24 19:44, 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.
> 
> Signed-off-by: James Morse <james.morse@arm.com>
> Tested-by: Peter Newman <peternewman@google.com>
> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Tested-by: Babu Moger <babu.moger@amd.com>
> Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
> 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>
> Reviewed-by: Babu Moger <babu.moger@amd.com>
> 
> ---

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb

[tip: x86/cache] x86/resctrl: Create helper for RMID allocation and mondata dir creation
Posted by tip-bot2 for James Morse 1 year, 10 months ago
The following commit has been merged into the x86/cache branch of tip:

Commit-ID:     b1de313979af99dc0f999656fc99bbcb52559a38
Gitweb:        https://git.kernel.org/tip/b1de313979af99dc0f999656fc99bbcb52559a38
Author:        James Morse <james.morse@arm.com>
AuthorDate:    Tue, 13 Feb 2024 18:44:17 
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Fri, 16 Feb 2024 19:18:31 +01:00

x86/resctrl: Create helper for RMID allocation and mondata dir creation

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.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
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>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-4-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
---
 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 aa24343..4ea5a87 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -3288,6 +3288,30 @@ out:
 	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)
@@ -3360,20 +3384,10 @@ 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);
 
 	/*
@@ -3381,8 +3395,6 @@ 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);