From: Fan Yu <fan.yu9@xxxxxxxxxx>
Enhanced display logic to conditionally show PSI information only
when successfully read, with helpful guidance for users to enable
PSI support (psi=1 cmdline parameter).
Signed-off-by: Fan Yu <fan.yu9@xxxxxxxxxx>
---
tools/accounting/delaytop.c | 182 +++++++++++++++++++++++-------------
1 file changed, 116 insertions(+), 66 deletions(-)
diff --git a/tools/accounting/delaytop.c b/tools/accounting/delaytop.c
index 7bd1a1eeb354..72cc500b44b1 100644
--- a/tools/accounting/delaytop.c
+++ b/tools/accounting/delaytop.c
@@ -44,13 +44,11 @@
#include <linux/cgroupstats.h>
#include <stddef.h>
-#define PSI_CPU_SOME "/proc/pressure/cpu"
-#define PSI_CPU_FULL "/proc/pressure/cpu"
-#define PSI_MEMORY_SOME "/proc/pressure/memory"
-#define PSI_MEMORY_FULL "/proc/pressure/memory"
-#define PSI_IO_SOME "/proc/pressure/io"
-#define PSI_IO_FULL "/proc/pressure/io"
-#define PSI_IRQ_FULL "/proc/pressure/irq"
+#define PSI_PATH "/proc/pressure"
+#define PSI_CPU_PATH "/proc/pressure/cpu"
+#define PSI_MEMORY_PATH "/proc/pressure/memory"
+#define PSI_IO_PATH "/proc/pressure/io"
+#define PSI_IRQ_PATH "/proc/pressure/irq"
#define NLA_NEXT(na) ((struct nlattr *)((char *)(na) + NLA_ALIGN((na)->nla_len)))
#define NLA_DATA(na) ((void *)((char *)(na) + NLA_HDRLEN))
@@ -499,87 +497,134 @@ static int get_family_id(int sd)
return id;
}
-static void read_psi_stats(void)
+static int read_psi_stats(void)
{
FILE *fp;
char line[256];
int ret = 0;
+ int error_count = 0;
+
+ /* Check if PSI path exists */
+ if (access(PSI_PATH, F_OK) != 0) {
+ fprintf(stderr, "Error: PSI interface not found at %s\n", PSI_PATH);
+ fprintf(stderr, "Please ensure your kernel supports PSI (Pressure Stall Information)\n");
+ return -1;
+ }
+
/* Zero all fields */
memset(&psi, 0, sizeof(psi));
+
/* CPU pressure */
- fp = fopen(PSI_CPU_SOME, "r");
+ fp = fopen(PSI_CPU_PATH, "r");
if (fp) {
while (fgets(line, sizeof(line), fp)) {
if (strncmp(line, "some", 4) == 0) {
ret = sscanf(line, "some avg10=%lf avg60=%lf avg300=%lf total=%llu",
&psi.cpu_some_avg10, &psi.cpu_some_avg60,
&psi.cpu_some_avg300, &psi.cpu_some_total);
- if (ret != 4)
+ if (ret != 4) {
fprintf(stderr, "Failed to parse CPU some PSI data\n");
+ error_count++;
+ }
} else if (strncmp(line, "full", 4) == 0) {
ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
&psi.cpu_full_avg10, &psi.cpu_full_avg60,
&psi.cpu_full_avg300, &psi.cpu_full_total);
- if (ret != 4)
+ if (ret != 4) {
fprintf(stderr, "Failed to parse CPU full PSI data\n");
+ error_count++;
+ }
}
}
fclose(fp);
+ } else {
+ fprintf(stderr, "Warning: Failed to open %s\n", PSI_CPU_PATH);
+ error_count++;
}
+
/* Memory pressure */
- fp = fopen(PSI_MEMORY_SOME, "r");
+ fp = fopen(PSI_MEMORY_PATH, "r");
if (fp) {
while (fgets(line, sizeof(line), fp)) {
if (strncmp(line, "some", 4) == 0) {
ret = sscanf(line, "some avg10=%lf avg60=%lf avg300=%lf total=%llu",
&psi.memory_some_avg10, &psi.memory_some_avg60,
&psi.memory_some_avg300, &psi.memory_some_total);
- if (ret != 4)
+ if (ret != 4) {
fprintf(stderr, "Failed to parse Memory some PSI data\n");
+ error_count++;
+ }
} else if (strncmp(line, "full", 4) == 0) {
ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
&psi.memory_full_avg10, &psi.memory_full_avg60,
&psi.memory_full_avg300, &psi.memory_full_total);
- }
- if (ret != 4)
+ if (ret != 4) {
fprintf(stderr, "Failed to parse Memory full PSI data\n");
+ error_count++;
+ }
+ }
}
fclose(fp);
+ } else {
+ fprintf(stderr, "Warning: Failed to open %s\n", PSI_MEMORY_PATH);
+ error_count++;
}
+
/* IO pressure */
- fp = fopen(PSI_IO_SOME, "r");
+ fp = fopen(PSI_IO_PATH, "r");
if (fp) {
while (fgets(line, sizeof(line), fp)) {
if (strncmp(line, "some", 4) == 0) {
ret = sscanf(line, "some avg10=%lf avg60=%lf avg300=%lf total=%llu",
&psi.io_some_avg10, &psi.io_some_avg60,
&psi.io_some_avg300, &psi.io_some_total);
- if (ret != 4)
+ if (ret != 4) {
fprintf(stderr, "Failed to parse IO some PSI data\n");
+ error_count++;
+ }
} else if (strncmp(line, "full", 4) == 0) {
ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
&psi.io_full_avg10, &psi.io_full_avg60,
&psi.io_full_avg300, &psi.io_full_total);
- if (ret != 4)
+ if (ret != 4) {
fprintf(stderr, "Failed to parse IO full PSI data\n");
+ error_count++;
+ }
}
}
fclose(fp);
+ } else {
+ fprintf(stderr, "Warning: Failed to open %s\n", PSI_IO_PATH);
+ error_count++;
}
+
/* IRQ pressure (only full) */
- fp = fopen(PSI_IRQ_FULL, "r");
+ fp = fopen(PSI_IRQ_PATH, "r");
if (fp) {
while (fgets(line, sizeof(line), fp)) {
if (strncmp(line, "full", 4) == 0) {
ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
&psi.irq_full_avg10, &psi.irq_full_avg60,
&psi.irq_full_avg300, &psi.irq_full_total);
- if (ret != 4)
+ if (ret != 4) {
fprintf(stderr, "Failed to parse IRQ full PSI data\n");
+ error_count++;
+ }
}
}
fclose(fp);
+ } else {
+ fprintf(stderr, "Warning: Failed to open %s\n", PSI_IRQ_PATH);
+ error_count++;
}
+
+ /* Return error count: 0 means success, >0 means warnings, -1 means fatal error */
+ if (error_count > 0) {
+ fprintf(stderr, "PSI stats reading completed with %d warnings\n", error_count);
+ return error_count;
+ }
+
+ return 0;
}
static int read_comm(int pid, char *comm_buf, size_t buf_size)
@@ -820,7 +865,7 @@ static void get_container_stats(void)
}
/* Display results to stdout or log file */
-static void display_results(void)
+static void display_results(int psi_ret)
{
time_t now = time(NULL);
struct tm *tm_now = localtime(&now);
@@ -833,49 +878,53 @@ static void display_results(void)
suc &= BOOL_FPRINT(out, "\033[H\033[J");
/* PSI output (one-line, no cat style) */
- suc &= BOOL_FPRINT(out, "System Pressure Information: (avg10/avg60/avg300/total)\n");
- suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
- "CPU some:",
- psi.cpu_some_avg10,
- psi.cpu_some_avg60,
- psi.cpu_some_avg300,
- psi.cpu_some_total / 1000);
- suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
- "CPU full:",
- psi.cpu_full_avg10,
- psi.cpu_full_avg60,
- psi.cpu_full_avg300,
- psi.cpu_full_total / 1000);
- suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
- "Memory full:",
- psi.memory_full_avg10,
- psi.memory_full_avg60,
- psi.memory_full_avg300,
- psi.memory_full_total / 1000);
- suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
- "Memory some:",
- psi.memory_some_avg10,
- psi.memory_some_avg60,
- psi.memory_some_avg300,
- psi.memory_some_total / 1000);
- suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
- "IO full:",
- psi.io_full_avg10,
- psi.io_full_avg60,
- psi.io_full_avg300,
- psi.io_full_total / 1000);
- suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
- "IO some:",
- psi.io_some_avg10,
- psi.io_some_avg60,
- psi.io_some_avg300,
- psi.io_some_total / 1000);
- suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
- "IRQ full:",
- psi.irq_full_avg10,
- psi.irq_full_avg60,
- psi.irq_full_avg300,
- psi.irq_full_total / 1000);
+ suc &= BOOL_FPRINT(out, "System Pressure Information: (avg10/avg60vg300/total)\n");
+ if (psi_ret) {
+ suc &= BOOL_FPRINT(out, " PSI not found: check if psi=1 enabled in cmdline\n");
+ } else {
+ suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+ "CPU some:",
+ psi.cpu_some_avg10,
+ psi.cpu_some_avg60,
+ psi.cpu_some_avg300,
+ psi.cpu_some_total / 1000);
+ suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+ "CPU full:",
+ psi.cpu_full_avg10,
+ psi.cpu_full_avg60,
+ psi.cpu_full_avg300,
+ psi.cpu_full_total / 1000);
+ suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+ "Memory full:",
+ psi.memory_full_avg10,
+ psi.memory_full_avg60,
+ psi.memory_full_avg300,
+ psi.memory_full_total / 1000);
+ suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+ "Memory some:",
+ psi.memory_some_avg10,
+ psi.memory_some_avg60,
+ psi.memory_some_avg300,
+ psi.memory_some_total / 1000);
+ suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+ "IO full:",
+ psi.io_full_avg10,
+ psi.io_full_avg60,
+ psi.io_full_avg300,
+ psi.io_full_total / 1000);
+ suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+ "IO some:",
+ psi.io_some_avg10,
+ psi.io_some_avg60,
+ psi.io_some_avg300,
+ psi.io_some_total / 1000);
+ suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+ "IRQ full:",
+ psi.irq_full_avg10,
+ psi.irq_full_avg60,
+ psi.irq_full_avg300,
+ psi.irq_full_total / 1000);
+ }
if (cfg.container_path) {
suc &= BOOL_FPRINT(out, "Container Information (%s):\n", cfg.container_path);
@@ -1017,6 +1066,7 @@ int main(int argc, char **argv)
{
const struct field_desc *field;
int iterations = 0;
+ int psi_ret = 0;
char keypress;
/* Parse command line arguments */
@@ -1054,7 +1104,7 @@ int main(int argc, char **argv)
}
/* Read PSI statistics */
- read_psi_stats();
+ psi_ret = read_psi_stats();
/* Get container stats if container path provided */
if (cfg.container_path)
@@ -1067,7 +1117,7 @@ int main(int argc, char **argv)
sort_tasks();
/* Display results to stdout or log file */
- display_results();
+ display_results(psi_ret);
/* Check for iterations */
if (cfg.iterations > 0 && ++iterations >= cfg.iterations)
--
2.25.1
