2016-11-03 21:09:12

by Shaohua Li

[permalink] [raw]
Subject: [PATCH 1/2] intel_rdt: fix a build warnning

gcc complains:
"warning: ‘dentry’ may be used uninitialized in this function"

Signed-off-by: Shaohua Li <[email protected]>
---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index a90ad22..e66c7a5 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -691,8 +691,10 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
closid_init();

ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
- if (ret)
+ if (ret) {
+ dentry = ERR_PTR(ret);
goto out_cdp;
+ }

dentry = kernfs_mount(fs_type, flags, rdt_root,
RDTGROUP_SUPER_MAGIC, NULL);
--
2.9.3



2016-11-03 21:09:11

by Shaohua Li

[permalink] [raw]
Subject: [PATCH 2/2] intel_rdt: export min_cbm_bits

min_cbm_bits could be 1 or 2 for L3 cache. Kenrel does check the bits
when writting mask. Unfortunately it's not exported to userspace. This
patch fixes the gap.

Signed-off-by: Shaohua Li <[email protected]>
---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index e66c7a5..4795880 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -472,6 +472,16 @@ static int rdt_cbm_mask_show(struct kernfs_open_file *of,
return 0;
}

+static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ seq_printf(seq, "%d\n", r->min_cbm_bits);
+
+ return 0;
+}
+
/* rdtgroup information files for one cache resource. */
static struct rftype res_info_files[] = {
{
@@ -486,6 +496,12 @@ static struct rftype res_info_files[] = {
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = rdt_cbm_mask_show,
},
+ {
+ .name = "min_cbm_bits",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_min_cbm_bits_show,
+ },
};

static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
--
2.9.3

Subject: [tip:x86/cache] x86/intel_rdt: Propagate error in rdt_mount() properly

Commit-ID: 7bff0af51012500718971f9cc3485f67252353eb
Gitweb: http://git.kernel.org/tip/7bff0af51012500718971f9cc3485f67252353eb
Author: Shaohua Li <[email protected]>
AuthorDate: Thu, 3 Nov 2016 14:09:05 -0700
Committer: Thomas Gleixner <[email protected]>
CommitDate: Mon, 7 Nov 2016 12:20:52 +0100

x86/intel_rdt: Propagate error in rdt_mount() properly

gcc complains:
"warning: ‘dentry’ may be used uninitialized in this function"

The error exit path in rdt_mount(), which deals with a failure in
rdtgroup_create_info_dir(), does not set the error code in dentry and
returns the uninitialized dentry value.

Add the missing error propagation.

[tglx: Massaged changelog ]
Fixes: 4e978d06dedb ("x86/intel_rdt: Add "info" files to resctrl file system")
Signed-off-by: Shaohua Li <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/a56a556f6768dc12cadbf97f49e000189056f90e.1478207143.git.shli@fb.com
Signed-off-by: Thomas Gleixner <[email protected]>

---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index a90ad22..e66c7a5 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -691,8 +691,10 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
closid_init();

ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
- if (ret)
+ if (ret) {
+ dentry = ERR_PTR(ret);
goto out_cdp;
+ }

dentry = kernfs_mount(fs_type, flags, rdt_root,
RDTGROUP_SUPER_MAGIC, NULL);

Subject: [tip:x86/cache] x86/intel_rdt: Export the minimum number of set mask bits in sysfs

Commit-ID: 53a114a69095eeb0e15d04c2a82358b3192f88df
Gitweb: http://git.kernel.org/tip/53a114a69095eeb0e15d04c2a82358b3192f88df
Author: Shaohua Li <[email protected]>
AuthorDate: Thu, 3 Nov 2016 14:09:06 -0700
Committer: Thomas Gleixner <[email protected]>
CommitDate: Mon, 7 Nov 2016 12:20:52 +0100

x86/intel_rdt: Export the minimum number of set mask bits in sysfs

The minimum number of bits set for a cache mask is checked by the kernel
when writing a mask, but there is no way for the user to retrieve this
information.

Add a new file 'min_cbm_bits' to the info directory and export the
information to user space.

[ tglx: Massaged changelog ]
Signed-off-by: Shaohua Li <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/e69b1ffa206d0353eea58101e1bf9b677d9732f7.1478207143.git.shli@fb.com
Signed-off-by: Thomas Gleixner <[email protected]>

---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index e66c7a5..4795880 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -472,6 +472,16 @@ static int rdt_cbm_mask_show(struct kernfs_open_file *of,
return 0;
}

+static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ seq_printf(seq, "%d\n", r->min_cbm_bits);
+
+ return 0;
+}
+
/* rdtgroup information files for one cache resource. */
static struct rftype res_info_files[] = {
{
@@ -486,6 +496,12 @@ static struct rftype res_info_files[] = {
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = rdt_cbm_mask_show,
},
+ {
+ .name = "min_cbm_bits",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_min_cbm_bits_show,
+ },
};

static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)