Skip to contentSkip to conversation

Add sysfs based cpuinfo structure.

RFC PATCH Greg KH 3 participants 7 messages Jun 8, 2017 – Jun 9, 2017 4 messages not in the archive

lore
Share & tools
lore

A message that is not in the archive (sent off-list or not yet received): [email protected]

A message that is not in the archive (sent off-list or not yet received): [email protected]

Greg KH

author
#2 lore raw
Quoted 8 lines · Felix Schnizlein

Create a new sysfs attribute group called 'cpuinfo' for each online cpu. The cleaned up cpuinfo shows up in a sysfs subdirectory here: /sys/devices/system/cpu/cpu*/cpuinfo.

Define preprocessor macros (CPUINFO_DEFINE_* and CPUINFO_ATTR) to make defining new sysfs attributes for cpuinfo more easy.

Signed-off-by Thomas Renninger <[email protected]>

But not you?

Quoted 53 lines
---
 drivers/base/Kconfig       |  7 ++++++
 drivers/base/Makefile      |  1 +
 drivers/base/cpuinfo.c     | 57 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/cpuhotplug.h |  1 +
 include/linux/cpuinfo.h    | 47 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 113 insertions(+)
 create mode 100644 drivers/base/cpuinfo.c
 create mode 100644 include/linux/cpuinfo.h
drivers/base/Kconfig +7 -0
index d718ae4..7900e31 100644
@@ -224,6 +224,13 @@ config DEBUG_TEST_DRIVER_REMOVE
 	  unusable. You should say N here unless you are explicitly looking to
 	  test this functionality.
 
+config CPUINFO_SYSFS
+	bool "Enable sysfs based cpuinfo"
+	depends on SYSFS && X86
+	default y
+	help
+	  This option enables cpuinfo in sysfs.
+
 source "drivers/base/test/Kconfig"
 
 config SYS_HYPERVISOR
drivers/base/Makefile +1 -0
index f2816f6..cbbba07 100644
@@ -23,6 +23,7 @@ obj-$(CONFIG_SOC_BUS) += soc.o
 obj-$(CONFIG_PINCTRL) += pinctrl.o
 obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
 obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o
+obj-$(CONFIG_CPUINFO_SYSFS) += cpuinfo.o
 
 obj-y			+= test/
drivers/base/cpuinfo.c new file +7 -0
new file mode 100644
index 0000000..52c21f2
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2017 SUSE Linux GmbH
+ * Written by: Felix Schnizlein <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.

drivers/base/cpuinfo.c line 17

Quoted 10 lines
drivers/base/cpuinfo.c new file +10 -0
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.

Did you run this through checkpatch.pl first? Please do so :)

thanks,

greg k-h

author
#3 lore raw
In reply to a message not in the archive
Quoted 23 lines · Felix Schnizlein

Create a new sysfs attribute group called 'cpuinfo' for each online cpu. The cleaned up cpuinfo shows up in a sysfs subdirectory here: /sys/devices/system/cpu/cpu*/cpuinfo.

Define preprocessor macros (CPUINFO_DEFINE_* and CPUINFO_ATTR) to make defining new sysfs attributes for cpuinfo more easy.

Signed-off-by Thomas Renninger <[email protected]>
---
 drivers/base/Kconfig       |  7 ++++++
 drivers/base/Makefile      |  1 +
 drivers/base/cpuinfo.c     | 57 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/cpuhotplug.h |  1 +
 include/linux/cpuinfo.h    | 47 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 113 insertions(+)
 create mode 100644 drivers/base/cpuinfo.c
 create mode 100644 include/linux/cpuinfo.h
drivers/base/Kconfig +0 -0
index d718ae4..7900e31 100644

drivers/base/Kconfig config DEBUG_TEST_DRIVER_REMOVE · line 232

Quoted 9 lines
drivers/base/Kconfig +6 -0
@@ -224,6 +224,13 @@ config DEBUG_TEST_DRIVER_REMOVE
 	  unusable. You should say N here unless you are explicitly looking to
 	  test this functionality.
 
+config CPUINFO_SYSFS
+	bool "Enable sysfs based cpuinfo"
+	depends on SYSFS && X86
+	default y
+	help
+	  This option enables cpuinfo in sysfs.

Why would you not want this? Why make it an option at all?

A message that is not in the archive (sent off-list or not yet received): [email protected]

author
#5 lore raw

Re: [RFC PATCH 2/3] Implement sysfs based cpuinfo for x86 cpus.

Quoted 9 lines · Felix Schnizlein

A few entries have been omitted, due to already existing information in sysfs:

- microcode -> /sys/devices/system/cpu/cpu*/microcode/version
- cache -> /sys/devices/system/cpu/cpu*/cache/index*/size
- core_id -> /sys/devices/system/cpu/cpu*/topology/core_id
- siblings -> /sys/devices/system/cpu/cpu*/topology/core_siblings_list
- pyshical_id -> /sys/devices/system/cpu/cpu*/topology/physical_package_id

Quoted 4 lines

Following attributes have been removed due to obsolete information or legacy processors: wp, power management, f00f bug, coma bug, fdiv bug

Signed-off-by Thomas Renninger <[email protected]>

Again, no signoff from you?

Quoted 7 lines
---
 arch/x86/kernel/Makefile        |   1 +
 arch/x86/kernel/cpuinfo_sysfs.c | 166 ++++++++++++++++++++++++++++++++++++++++
 drivers/base/cpuinfo.c          |   4 -
 3 files changed, 167 insertions(+), 4 deletions(-)
 create mode 100644 arch/x86/kernel/cpuinfo_sysfs.c

When you add new sysfs entries, you have to also add new Documentation/ABI/ entries.

thanks,

greg k-h

#6 lore raw

Re: [RFC PATCH 2/3] Implement sysfs based cpuinfo for x86 cpus.

Quoted 4 lines · Greg KH
Quoted 3 lines · Felix Schnizlein
---
 arch/x86/kernel/Makefile        |   1 +
 arch/x86/kernel/cpuinfo_sysfs.c | 166

++++++++++++++++++++++++++++++++++++++++

Quoted 7 lines
Quoted 4 lines
 drivers/base/cpuinfo.c          |   4 -
 3 files changed, 167 insertions(+), 4 deletions(-)
 create mode 100644 arch/x86/kernel/cpuinfo_sysfs.c

When you add new sysfs entries, you have to also add new Documentation/ABI/ entries.

This one seem to be rather unmaintained?
There even is:
Documentation/ABI/stable/sysfs-devices-system-cpu this patchset would have to add:
Documentation/ABI/stable/sysfs-devices-system-cpu-cpuinfo then.

But:
Documentation/ABI/stable/sysfs-devices-system-cpu describes
/sys/devices/system/cpu/dscr_default
and
/sys/devices/system/cpu/cpu[0-9]+/dscr

which I have never seen.

Much more important values in there like:
/sys/devices/system/cpu/topology
/sys/devices/system/cpu/microcode
/sys/devices/system/cpu/cpuidle
/sys/devices/system/cpu/cpufreq
/sys/devices/system/cpu/{online,offline}

are not described there at all.

I wonder whether .../cpu/dscr_default still exists in the kernel, a quick grep did not reveal anything.
A
Source:
tag would be a nice non-optional addition in the README.

We can also send definitions for topology/microcode/cache/.. to catch up a bit there again, not sure that makes much sense.

Be aware that the output of /proc/cpuinfo is rather arbitrary depending on architecure and some build options.

Thomas

#7 lore raw

Re: [RFC PATCH 2/3] Implement sysfs based cpuinfo for x86 cpus.

Quoted 26 lines · Thomas Renninger
Quoted 4 lines · Greg KH
Quoted 3 lines · Felix Schnizlein
---
 arch/x86/kernel/Makefile        |   1 +
 arch/x86/kernel/cpuinfo_sysfs.c | 166

++++++++++++++++++++++++++++++++++++++++

Quoted 6 lines
Quoted 4 lines
 drivers/base/cpuinfo.c          |   4 -
 3 files changed, 167 insertions(+), 4 deletions(-)
 create mode 100644 arch/x86/kernel/cpuinfo_sysfs.c

When you add new sysfs entries, you have to also add new Documentation/ABI/ entries.

This one seem to be rather unmaintained?
There even is:
Documentation/ABI/stable/sysfs-devices-system-cpu this patchset would have to add:
Documentation/ABI/stable/sysfs-devices-system-cpu-cpuinfo then.

But:
Documentation/ABI/stable/sysfs-devices-system-cpu describes
/sys/devices/system/cpu/dscr_default
and
/sys/devices/system/cpu/cpu[0-9]+/dscr

Quoted 8 lines

which I have never seen.

Much more important values in there like:
/sys/devices/system/cpu/topology
/sys/devices/system/cpu/microcode
/sys/devices/system/cpu/cpuidle
/sys/devices/system/cpu/cpufreq
/sys/devices/system/cpu/{online,offline}

They are documented in Documentation/ABI/testing/sysfs-devices-system-cpu (which doesn't contain dscr)

Brice

Quoted 16 lines

are not described there at all.

I wonder whether .../cpu/dscr_default still exists in the kernel, a quick grep did not reveal anything.
A
Source:
tag would be a nice non-optional addition in the README.

We can also send definitions for topology/microcode/cache/.. to catch up a bit there again, not sure that makes much sense.

Be aware that the output of /proc/cpuinfo is rather arbitrary depending on architecure and some build options.

Thomas

author
#8 lore raw

Re: [RFC PATCH 2/3] Implement sysfs based cpuinfo for x86 cpus.

In reply to a message not in the archive
Quoted 9 lines · Felix Schnizlein

A few entries have been omitted, due to already existing information in sysfs:

- microcode -> /sys/devices/system/cpu/cpu*/microcode/version
- cache -> /sys/devices/system/cpu/cpu*/cache/index*/size
- core_id -> /sys/devices/system/cpu/cpu*/topology/core_id
- siblings -> /sys/devices/system/cpu/cpu*/topology/core_siblings_list
- pyshical_id -> /sys/devices/system/cpu/cpu*/topology/physical_package_id

Quoted 4 lines

Following attributes have been removed due to obsolete information or legacy processors: wp, power management, f00f bug, coma bug, fdiv bug

Signed-off-by Thomas Renninger <[email protected]>

???

Quoted 12 lines
---
 arch/x86/kernel/Makefile        |   1 +
 arch/x86/kernel/cpuinfo_sysfs.c | 166 ++++++++++++++++++++++++++++++++++++++++
 drivers/base/cpuinfo.c          |   4 -
 3 files changed, 167 insertions(+), 4 deletions(-)
 create mode 100644 arch/x86/kernel/cpuinfo_sysfs.c
arch/x86/kernel/Makefile +0 -0
index 4b99423..5c689d9 100644

arch/x86/kernel/Makefile obj-y += step.o · line 68

Quoted 4 lines
arch/x86/kernel/Makefile +1 -0
@@ -65,6 +65,7 @@ obj-y				+= step.o
 obj-$(CONFIG_INTEL_TXT)		+= tboot.o
 obj-$(CONFIG_ISA_DMA_API)	+= i8237.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
+obj-$(CONFIG_CPUINFO_SYSFS)     += cpuinfo_sysfs.o

Use tabs properly please.

A message that is not in the archive (sent off-list or not yet received): [email protected]

author
#10 lore raw

Re: [RFC PATCH 3/3] Add deprecation warning to cpuinfo proc

Quoted 12 lines · Felix Schnizlein

Enable deprecation warning if the kernel was compiled with sysfs cpuinfo.

Signed-off-by Thomas Renninger <[email protected]>
---
 fs/proc/cpuinfo.c | 4 ++++
 1 file changed, 4 insertions(+)
fs/proc/cpuinfo.c +0 -0
index 06f4d31..044f56e 100644

fs/proc/cpuinfo.c line 11

Quoted 6 lines
fs/proc/cpuinfo.c +3 -0
@@ -6,6 +6,10 @@
 extern const struct seq_operations cpuinfo_op;
 static int cpuinfo_open(struct inode *inode, struct file *file)
 {
+#ifdef CONFIG_CPUINFO_SYSFS
+	pr_info("Do not access deprecated file /proc/cpuinfo, "
+		"opened by: (%s,%d)\n", current->comm, current->pid);

Hah, that's not going to happen. Do you know just how many different programs open this file for no good reason? Well, they think it's a good reason...

You are just going to spam syslog so hard, it's going to be annoying. This patch is not ok at all, sorry.

It's not like we are ever going to get rid of /proc/cpuinfo so it's not a big deal.

thanks,

greg k-h