diff mbox series

[v8,3/3] powerpc/sysfs: Add topology/smallcore_thread_siblings[_list]

Message ID 1537464159-25919-4-git-send-email-ego@linux.vnet.ibm.com (mailing list archive)
State Superseded
Headers show
Series powerpc: Detection and scheduler optimization for POWER9 bigcore | expand

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Commit Message

Gautham R Shenoy Sept. 20, 2018, 5:22 p.m. UTC 
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

This patch adds two sysfs attributes named smallcore_thread_siblings
and smallcore_thread_siblings_list to the "topology" attribute group
for each CPU device.

The read-only attributes
/sys/device/system/cpu/cpuN/topology/smallcore_thread_siblings and
/sys/device/system/cpu/cpuN/topology/smallcore_thread_siblings_list
will the online siblings of CPU N that share the L1 cache with it on
big-core configurations in cpumask format and cpu-list format
respectively.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
 Documentation/ABI/testing/sysfs-devices-system-cpu | 14 ++++
 arch/powerpc/kernel/sysfs.c                        | 88 ++++++++++++++++++++++
 2 files changed, 102 insertions(+)

Comments

kernel test robot Sept. 21, 2018, 6:20 a.m. UTC | #1 
Hi Gautham,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.19-rc4 next-20180919]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Gautham-R-Shenoy/powerpc-Detection-and-scheduler-optimization-for-POWER9-bigcore/20180921-085812
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-mpc837x_mds_defconfig (attached as .config)
compiler: powerpc-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.2.0 make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

   arch/powerpc/kernel/sysfs.c: In function 'smallcore_thread_siblings_show':
>> arch/powerpc/kernel/sysfs.c:724:45: error: implicit declaration of function 'cpu_smallcore_mask'; did you mean 'cpu_all_mask'? [-Werror=implicit-function-declaration]
     return cpumap_print_to_pagebuf(false, buf, cpu_smallcore_mask(cpu));
                                                ^~~~~~~~~~~~~~~~~~
                                                cpu_all_mask
>> arch/powerpc/kernel/sysfs.c:724:45: error: passing argument 3 of 'cpumap_print_to_pagebuf' makes pointer from integer without a cast [-Werror=int-conversion]
   In file included from include/linux/rcupdate.h:44:0,
                    from include/linux/radix-tree.h:28,
                    from include/linux/idr.h:15,
                    from include/linux/kernfs.h:14,
                    from include/linux/sysfs.h:16,
                    from include/linux/kobject.h:20,
                    from include/linux/device.h:16,
                    from arch/powerpc/kernel/sysfs.c:1:
   include/linux/cpumask.h:892:1: note: expected 'const struct cpumask *' but argument is of type 'int'
    cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
    ^~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/kernel/sysfs.c: In function 'smallcore_thread_siblings_list_show':
   arch/powerpc/kernel/sysfs.c:734:44: error: passing argument 3 of 'cpumap_print_to_pagebuf' makes pointer from integer without a cast [-Werror=int-conversion]
     return cpumap_print_to_pagebuf(true, buf, cpu_smallcore_mask(cpu));
                                               ^~~~~~~~~~~~~~~~~~
   In file included from include/linux/rcupdate.h:44:0,
                    from include/linux/radix-tree.h:28,
                    from include/linux/idr.h:15,
                    from include/linux/kernfs.h:14,
                    from include/linux/sysfs.h:16,
                    from include/linux/kobject.h:20,
                    from include/linux/device.h:16,
                    from arch/powerpc/kernel/sysfs.c:1:
   include/linux/cpumask.h:892:1: note: expected 'const struct cpumask *' but argument is of type 'int'
    cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
    ^~~~~~~~~~~~~~~~~~~~~~~
   cc1: all warnings being treated as errors

vim +724 arch/powerpc/kernel/sysfs.c

   717	
   718	static ssize_t smallcore_thread_siblings_show(struct device *dev,
   719						struct device_attribute *attr,
   720						char *buf)
   721	{
   722		int cpu = dev->id;
   723	
 > 724		return cpumap_print_to_pagebuf(false, buf, cpu_smallcore_mask(cpu));
   725	}
   726	static DEVICE_ATTR_RO(smallcore_thread_siblings);
   727	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Gautham R Shenoy Sept. 21, 2018, 5:20 p.m. UTC | #2 
On Fri, Sep 21, 2018 at 02:20:15PM +0800, kbuild test robot wrote:
> Hi Gautham,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on powerpc/next]
> [also build test ERROR on v4.19-rc4 next-20180919]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> 
> url:    https://github.com/0day-ci/linux/commits/Gautham-R-Shenoy/powerpc-Detection-and-scheduler-optimization-for-POWER9-bigcore/20180921-085812
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
> config: powerpc-mpc837x_mds_defconfig (attached as .config)
> compiler: powerpc-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         GCC_VERSION=7.2.0 make.cross ARCH=powerpc 
> 
> All errors (new ones prefixed by >>):
> 
>    arch/powerpc/kernel/sysfs.c: In function 'smallcore_thread_siblings_show':
> >> arch/powerpc/kernel/sysfs.c:724:45: error: implicit declaration of function 'cpu_smallcore_mask'; did you mean 'cpu_all_mask'? [-Werror=implicit-function-declaration]
>      return cpumap_print_to_pagebuf(false, buf, cpu_smallcore_mask(cpu));
>                                                 ^~~~~~~~~~~~~~~~~~


No, the smallcore_thread_siblings_show, and the other functions should
only be compiled for CONFIG_SMP.


Will add this. Thanks bot!

>                                                 cpu_all_mask
> >> arch/powerpc/kernel/sysfs.c:724:45: error: passing argument 3 of 'cpumap_print_to_pagebuf' makes pointer from integer without a cast [-Werror=int-conversion]
>    In file included from include/linux/rcupdate.h:44:0,
>                     from include/linux/radix-tree.h:28,
>                     from include/linux/idr.h:15,
>                     from include/linux/kernfs.h:14,
>                     from include/linux/sysfs.h:16,
>                     from include/linux/kobject.h:20,
>                     from include/linux/device.h:16,
>                     from arch/powerpc/kernel/sysfs.c:1:
>    include/linux/cpumask.h:892:1: note: expected 'const struct cpumask *' but argument is of type 'int'
>     cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
>     ^~~~~~~~~~~~~~~~~~~~~~~
>    arch/powerpc/kernel/sysfs.c: In function 'smallcore_thread_siblings_list_show':
>    arch/powerpc/kernel/sysfs.c:734:44: error: passing argument 3 of 'cpumap_print_to_pagebuf' makes pointer from integer without a cast [-Werror=int-conversion]
>      return cpumap_print_to_pagebuf(true, buf, cpu_smallcore_mask(cpu));
>                                                ^~~~~~~~~~~~~~~~~~
>    In file included from include/linux/rcupdate.h:44:0,
>                     from include/linux/radix-tree.h:28,
>                     from include/linux/idr.h:15,
>                     from include/linux/kernfs.h:14,
>                     from include/linux/sysfs.h:16,
>                     from include/linux/kobject.h:20,
>                     from include/linux/device.h:16,
>                     from arch/powerpc/kernel/sysfs.c:1:
>    include/linux/cpumask.h:892:1: note: expected 'const struct cpumask *' but argument is of type 'int'
>     cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
>     ^~~~~~~~~~~~~~~~~~~~~~~
>    cc1: all warnings being treated as errors
> 
> vim +724 arch/powerpc/kernel/sysfs.c
> 
>    717	
>    718	static ssize_t smallcore_thread_siblings_show(struct device *dev,
>    719						struct device_attribute *attr,
>    720						char *buf)
>    721	{
>    722		int cpu = dev->id;
>    723	
>  > 724		return cpumap_print_to_pagebuf(false, buf, cpu_smallcore_mask(cpu));
>    725	}
>    726	static DEVICE_ATTR_RO(smallcore_thread_siblings);
>    727	
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 7331822..2a80dc2 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -511,3 +511,17 @@  Description:	Control Symetric Multi Threading (SMT)
 
 			 If control status is "forceoff" or "notsupported" writes
 			 are rejected.
+
+What:		/sys/devices/system/cpu/cpu#/topology/smallcore_thread_siblings
+		/sys/devices/system/cpu/cpu#/topology/smallcore_thread_siblings_list
+Date:		Sept 2018
+Contact:	Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description: 	CPU topology files that describe the thread siblings of a
+		logical CPU that share the L1-cache with it on POWER9
+		big-core configurations.
+
+		smallcore_thread_siblings: internal kernel map of
+		cpu#'s hardware threads that share L1-cache with cpu#.
+
+		smallcore_thread_siblings_list: human-readable list of
+		cpu#'s hardware threads that share L1-cache with cpu#.
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 755dc98..f9c7d96 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -18,6 +18,7 @@ 
 #include <asm/smp.h>
 #include <asm/pmc.h>
 #include <asm/firmware.h>
+#include <asm/cputhreads.h>
 
 #include "cacheinfo.h"
 #include "setup.h"
@@ -714,6 +715,62 @@  static void sysfs_create_dscr_default(void)
 #endif /* HAS_PPC_PMC_PA6T */
 #endif /* HAS_PPC_PMC_CLASSIC */
 
+static ssize_t smallcore_thread_siblings_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	int cpu = dev->id;
+
+	return cpumap_print_to_pagebuf(false, buf, cpu_smallcore_mask(cpu));
+}
+static DEVICE_ATTR_RO(smallcore_thread_siblings);
+
+static ssize_t smallcore_thread_siblings_list_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	int cpu = dev->id;
+
+	return cpumap_print_to_pagebuf(true, buf, cpu_smallcore_mask(cpu));
+}
+static DEVICE_ATTR_RO(smallcore_thread_siblings_list);
+
+static struct attribute *smallcore_attrs[] = {
+	&dev_attr_smallcore_thread_siblings.attr,
+	&dev_attr_smallcore_thread_siblings_list.attr,
+	NULL
+};
+
+static const struct attribute_group smallcore_attr_group = {
+	.name = "topology",
+	.attrs = smallcore_attrs
+};
+
+static int smallcore_register_cpu_online(unsigned int cpu)
+{
+	int err;
+	struct device *cpu_dev = get_cpu_device(cpu);
+
+	if (!has_big_cores)
+		return 0;
+
+	err = sysfs_merge_group(&cpu_dev->kobj, &smallcore_attr_group);
+
+	return err;
+}
+
+static int smallcore_unregister_cpu_online(unsigned int cpu)
+{
+	struct device *cpu_dev = get_cpu_device(cpu);
+
+	if (!has_big_cores)
+		return 0;
+
+	sysfs_unmerge_group(&cpu_dev->kobj, &smallcore_attr_group);
+
+	return 0;
+}
+
 static int register_cpu_online(unsigned int cpu)
 {
 	struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -1060,3 +1117,34 @@  static int __init topology_init(void)
 	return 0;
 }
 subsys_initcall(topology_init);
+
+/*
+ * NOTE: The smallcore_register_cpu_online
+ *       (resp. smallcore_unregister_cpu_online) callback will merge
+ *       (resp. unmerge) a couple of additional attributes to the
+ *       "topology" attribute group of a CPU device when the CPU comes
+ *       online (resp. goes offline).
+ *
+ *       Hence, the registration of these callbacks must happen after
+ *       topology_sysfs_init() is called so that the topology
+ *       attribute group is created before these additional attributes
+ *       can be merged/unmerged. We cannot register these callbacks in
+ *       topology_init() since this function is called before
+ *       topology_sysfs_init(). Hence we define the following
+ *       late_initcall for this purpose.
+ */
+static int __init smallcore_topology_init(void)
+{
+	int r;
+
+	if (!has_big_cores)
+		return 0;
+
+	r = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+			      "powerpc/topology/smallcore:online",
+			      smallcore_register_cpu_online,
+			      smallcore_unregister_cpu_online);
+	WARN_ON(r < 0);
+	return 0;
+}
+late_initcall(smallcore_topology_init);