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From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
To: Nathan Lynch <nathanl@linux.ibm.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
	Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
	"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
	Tyrel Datwyler <tyreld@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	"Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
Subject: [PATCH v4 4/6] powerpc/sysfs: Show idle_purr and idle_spurr for every CPU
Date: Fri, 27 Mar 2020 17:02:38 +0530	[thread overview]
Message-ID: <1585308760-28792-5-git-send-email-ego@linux.vnet.ibm.com> (raw)
In-Reply-To: <1585308760-28792-1-git-send-email-ego@linux.vnet.ibm.com>

From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

On Pseries LPARs, to calculate utilization, we need to know the
[S]PURR ticks when the CPUs were busy or idle.

The total PURR and SPURR ticks are already exposed via the per-cpu
sysfs files "purr" and "spurr". This patch adds support for exposing
the idle PURR and SPURR ticks via new per-cpu sysfs files named
"idle_purr" and "idle_spurr".

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/sysfs.c | 82 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 79 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 479c706..571b325 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -19,6 +19,7 @@
 #include <asm/smp.h>
 #include <asm/pmc.h>
 #include <asm/firmware.h>
+#include <asm/idle.h>
 #include <asm/svm.h>
 
 #include "cacheinfo.h"
@@ -760,6 +761,74 @@ static void create_svm_file(void)
 }
 #endif /* CONFIG_PPC_SVM */
 
+#ifdef CONFIG_PPC_PSERIES
+static void read_idle_purr(void *val)
+{
+	u64 *ret = val;
+
+	*ret = read_this_idle_purr();
+}
+
+static ssize_t idle_purr_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
+	u64 val;
+
+	smp_call_function_single(cpu->dev.id, read_idle_purr, &val, 1);
+	return sprintf(buf, "%llx\n", val);
+}
+static DEVICE_ATTR(idle_purr, 0400, idle_purr_show, NULL);
+
+static void create_idle_purr_file(struct device *s)
+{
+	if (firmware_has_feature(FW_FEATURE_LPAR))
+		device_create_file(s, &dev_attr_idle_purr);
+}
+
+static void remove_idle_purr_file(struct device *s)
+{
+	if (firmware_has_feature(FW_FEATURE_LPAR))
+		device_remove_file(s, &dev_attr_idle_purr);
+}
+
+static void read_idle_spurr(void *val)
+{
+	u64 *ret = val;
+
+	*ret = read_this_idle_spurr();
+}
+
+static ssize_t idle_spurr_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
+	u64 val;
+
+	smp_call_function_single(cpu->dev.id, read_idle_spurr, &val, 1);
+	return sprintf(buf, "%llx\n", val);
+}
+static DEVICE_ATTR(idle_spurr, 0400, idle_spurr_show, NULL);
+
+static void create_idle_spurr_file(struct device *s)
+{
+	if (firmware_has_feature(FW_FEATURE_LPAR))
+		device_create_file(s, &dev_attr_idle_spurr);
+}
+
+static void remove_idle_spurr_file(struct device *s)
+{
+	if (firmware_has_feature(FW_FEATURE_LPAR))
+		device_remove_file(s, &dev_attr_idle_spurr);
+}
+
+#else /* CONFIG_PPC_PSERIES */
+#define create_idle_purr_file(s)
+#define remove_idle_purr_file(s)
+#define create_idle_spurr_file(s)
+#define remove_idle_spurr_file(s)
+#endif /* CONFIG_PPC_PSERIES */
+
 static int register_cpu_online(unsigned int cpu)
 {
 	struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -823,10 +892,13 @@ static int register_cpu_online(unsigned int cpu)
 		if (!firmware_has_feature(FW_FEATURE_LPAR))
 			add_write_permission_dev_attr(&dev_attr_purr);
 		device_create_file(s, &dev_attr_purr);
+		create_idle_purr_file(s);
 	}
 
-	if (cpu_has_feature(CPU_FTR_SPURR))
+	if (cpu_has_feature(CPU_FTR_SPURR)) {
 		device_create_file(s, &dev_attr_spurr);
+		create_idle_spurr_file(s);
+	}
 
 	if (cpu_has_feature(CPU_FTR_DSCR))
 		device_create_file(s, &dev_attr_dscr);
@@ -910,11 +982,15 @@ static int unregister_cpu_online(unsigned int cpu)
 		device_remove_file(s, &dev_attr_mmcra);
 #endif /* CONFIG_PMU_SYSFS */
 
-	if (cpu_has_feature(CPU_FTR_PURR))
+	if (cpu_has_feature(CPU_FTR_PURR)) {
 		device_remove_file(s, &dev_attr_purr);
+		remove_idle_purr_file(s);
+	}
 
-	if (cpu_has_feature(CPU_FTR_SPURR))
+	if (cpu_has_feature(CPU_FTR_SPURR)) {
 		device_remove_file(s, &dev_attr_spurr);
+		remove_idle_spurr_file(s);
+	}
 
 	if (cpu_has_feature(CPU_FTR_DSCR))
 		device_remove_file(s, &dev_attr_dscr);
-- 
1.9.4


  parent reply	other threads:[~2020-03-27 11:33 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-27 11:32 [PATCH v4 0/6] [PATCH v4 0/6] Track and expose idle PURR and SPURR ticks Gautham R. Shenoy
2020-03-27 11:32 ` [PATCH v4 1/6] powerpc: Move idle_loop_prolog()/epilog() functions to header file Gautham R. Shenoy
2020-03-27 11:32 ` [PATCH v4 2/6] powerpc/idle: Add accessor function to always read latest idle PURR Gautham R. Shenoy
2020-04-01  9:42   ` Naveen N. Rao
2020-04-03  6:15     ` Gautham R Shenoy
2020-04-03 10:34       ` Naveen N. Rao
2020-04-03 11:24         ` Gautham R Shenoy
2020-03-27 11:32 ` [PATCH v4 3/6] powerpc/pseries: Account for SPURR ticks on idle CPUs Gautham R. Shenoy
2020-03-27 11:32 ` Gautham R. Shenoy [this message]
2020-03-27 11:32 ` [PATCH v4 5/6] Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurr Gautham R. Shenoy
2020-04-01  9:45   ` Naveen N. Rao
2020-03-27 11:32 ` [PATCH v4 6/6] pseries/sysfs: Minimise IPI noise while reading [idle_][s]purr Gautham R. Shenoy
2020-04-01  9:58   ` Naveen N. Rao
2020-04-01 12:01     ` Gautham R Shenoy
2020-04-02  7:34       ` Naveen N. Rao
2020-04-03  6:28         ` Gautham R Shenoy
2020-04-03 18:10           ` Nathan Lynch

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