From 2b3835481998917bf1c904b3262d38cd01576f59 Mon Sep 17 00:00:00 2001
From: Sebastien GODARD <sysstat@users.noreply.github.com>
Date: Sat, 19 Nov 2016 17:53:47 +0100
Subject: [PATCH] sar: Allow selection of a range of CPU

Update sar so that the user can now select a range of CPUs with option -P
(in addition to selecting an individual CPU). It is also possible to
select CPU "all" which is the global average among all CPUs (not to be
confused with the "ALL" keyword which selects all the CPUs of the
machine).

E.g.:

sar -P 0,3-5,12-	Selects CPUs #0, #3, #4, #5, and all the CPUs
from #12 and following.

sar -P all,1		Select CPU #1 and the global average CPU value
among all processors.

This patch will be reworked to cover mpstat.

Signed-off-by: Sebastien GODARD <sysstat@users.noreply.github.com>
---
 common.h    |  9 ++++---
 sa_common.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 70 insertions(+), 11 deletions(-)

diff --git a/common.h b/common.h
index 14711fd..3bb1efc 100644
--- a/common.h
+++ b/common.h
@@ -53,10 +53,11 @@
 #define INTERRUPTS_LINE	128
 
 /* Keywords */
-#define K_ISO	"ISO"
-#define K_ALL	"ALL"
-#define K_UTC	"UTC"
-#define K_JSON	"JSON"
+#define K_ISO		"ISO"
+#define K_ALL		"ALL"
+#define K_LOWERALL	"all"
+#define K_UTC		"UTC"
+#define K_JSON		"JSON"
 
 /* Files */
 #define STAT			"/proc/stat"
diff --git a/sa_common.c b/sa_common.c
index e58f0a1..3cbed1d 100644
--- a/sa_common.c
+++ b/sa_common.c
@@ -1970,6 +1970,37 @@ int parse_sar_I_opt(char *argv[], int *opt, struct activity *act[])
 	return 0;
 }
 
+/*
+ ***************************************************************************
+ * Parse a CPU string. The string should contain an individual CPU number.
+ *
+ * IN:
+ * @s		CPU string.
+ * @b_size	Size of the CPU bitmap.
+ *
+ * OUT:
+ * @cpu		CPU value, or -1 if the cpu string @s was empty.
+ *
+ * RETURNS:
+ * 0 if the CPU value has been properly read, 1 otherwise.
+ ***************************************************************************
+ */
+int parse_cpu_nr(char *s, int b_size, int *cpu)
+{
+	if (!strlen(s)) {
+		*cpu = -1;
+		return 0;
+	}
+	if (strspn(s, DIGITS) != strlen(s))
+		return 1;
+
+	*cpu = atoi(s);
+	if ((*cpu < 0) || (*cpu >= b_size))
+		return 1;
+
+	return 0;
+}
+
 /*
  ***************************************************************************
  * Parse sar and sadf "-P" option.
@@ -1989,8 +2020,8 @@ int parse_sar_I_opt(char *argv[], int *opt, struct activity *act[])
  */
 int parse_sa_P_opt(char *argv[], int *opt, unsigned int *flags, struct activity *act[])
 {
-	int i, p;
-	char *t;
+	int i, p, cpu_low, cpu;
+	char *t, *s, *cpustr, range[16];
 
 	p = get_activity_position(act, A_CPU, EXIT_IF_NOT_FOUND);
 
@@ -2006,14 +2037,41 @@ int parse_sa_P_opt(char *argv[], int *opt, unsigned int *flags, struct activity
 				set_bitmap(act[p]->bitmap->b_array, ~0,
 					   BITMAP_SIZE(act[p]->bitmap->b_size));
 			}
+			else if (!strcmp(t, K_LOWERALL)) {
+				/* Select CPU "all" (ie. global average CPU) */
+				act[p]->bitmap->b_array[0] |= 1;
+			}
 			else {
-				/* Get cpu number */
-				if (strspn(t, DIGITS) != strlen(t))
+				/* Parse CPU number or range of CPU */
+				strncpy(range, t, 16);
+				range[15] = '\0';
+				cpustr = t;
+				if ((s = index(range, '-')) != NULL) {
+					/* Possible range of CPU */
+					*s = '\0';
+					if (parse_cpu_nr(range, act[p]->bitmap->b_size, &cpu_low) || (cpu_low < 0))
+						return 1;
+					cpustr = s + 1;
+				}
+				if (parse_cpu_nr(cpustr, act[p]->bitmap->b_size, &cpu))
 					return 1;
-				i = atoi(t);
-				if ((i < 0) || (i >= act[p]->bitmap->b_size))
+				if (s && cpu < 0) {
+					/* Range of CPU with no upper limit (e.g. "3-") */
+					cpu = act[p]->bitmap->b_size - 1;
+				}
+				if ((!s && (cpu < 0)) || (s && (cpu < cpu_low)))
+					/*
+					 * Individual CPU: string cannot be empty.
+					 * Range of CPU: n-m: m can be empty (e.g. "3-") but
+					 * cannot be lower than n.
+					 */
 					return 1;
-				act[p]->bitmap->b_array[(i + 1) >> 3] |= 1 << ((i + 1) & 0x07);
+				if (!s) {
+					cpu_low = cpu;
+				}
+				for (i = cpu_low; i <= cpu; i++) {
+					act[p]->bitmap->b_array[(i + 1) >> 3] |= 1 << ((i + 1) & 0x07);
+				}
 			}
 		}
 		(*opt)++;
-- 
2.40.0