* + delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch added to mm-nonmm-unstable branch
@ 2026-07-02 23:02 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-07-02 23:02 UTC (permalink / raw)
To: mm-commits, yang.yang29, xu.xin16, fan.yu9, corbet, wang.yaxin,
akpm
The patch titled
Subject: delaytop: sort by max delay to highlight top latency processes
has been added to the -mm mm-nonmm-unstable branch. Its filename is
delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: Wang Yaxin <wang.yaxin@zte.com.cn>
Subject: delaytop: sort by max delay to highlight top latency processes
Date: Thu, 2 Jul 2026 21:00:00 +0800 (CST)
When using -t/--type option, sort tasks by the maximum delay value of the
selected type in descending order (largest delay first).
This enables quickly identifying the top N processes with the highest
delay spikes, which is essential for diagnosing latency problems by
pinpointing which processes contributed most to system delays.
Link: https://lore.kernel.org/20260702210000676TkC9mShguDS_34k8M6AtP@zte.com.cn
Signed-off-by: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: Fan Yu <fan.yu9@zte.com.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
Documentation/accounting/delay-accounting.rst | 43 +++++++++
tools/accounting/delaytop.c | 71 +++++++++++++---
tools/accounting/getdelays.c | 5 +
3 files changed, 108 insertions(+), 11 deletions(-)
--- a/Documentation/accounting/delay-accounting.rst~delaytop-sort-by-max-delay-to-highlight-top-latency-processes
+++ a/Documentation/accounting/delay-accounting.rst
@@ -212,3 +212,46 @@ Advanced usage examples::
# ./delaytop -d secs
Specify refresh interval as secs
+
+ # ./delaytop -t type
+ Display only specified delay type with avg/max/timestamp
+ (rows sorted by MAX for that type, largest first)
+
+
+
+delaytop add delay_max fields to track the maximum delay value for each delay type
+(cpu, blkio, irq, swapin, freepages, thrashing, compact, wpcopy) per task.
+
+ bash# ./delaytop -t cpu
+ System Pressure Information: (avg10/avg60/avg300/total)
+ CPU some: 0.4%/ 0.2%/ 0.1%/ 220(ms)
+ CPU full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ Memory full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ Memory some: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ IO full: 0.0%/ 0.0%/ 0.0%/ 12(ms)
+ IO some: 0.0%/ 0.0%/ 0.0%/ 13(ms)
+ IRQ full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ [q]quit
+ Top 20 processes (sorted by cpu MAX delay, largest first):
+ PID TGID COMMAND AVG(ms) MAX(ms) MAX_TIMESTAMP
+ ------------------------------------------------------------------------
+ 9 9 kworker/0:0-eve 0.59 16.87 2026-05-27T13:32:39
+ 30 30 kworker/2:0H-kb 2.87 11.36 2026-05-27T13:32:36
+ 27 27 migration/2 1.05 9.51 2026-05-27T13:32:37
+ 50 50 kworker/2:1-eve 0.50 9.13 2026-05-27T13:32:37
+ 15 15 rcu_preempt 0.11 8.98 2026-05-27T13:32:37
+ 1 1 init 0.17 7.12 2026-05-27T13:32:38
+ 67 67 scsi_eh_0 1.20 4.23 2026-05-27T13:32:37
+ 23 23 ksoftirqd/1 1.12 3.77 2026-05-27T13:32:36
+ 3 3 pool_workqueue_ 0.72 3.55 2026-05-27T13:32:38
+ 62 62 kworker/u20:2-a 0.49 3.03 2026-05-27T13:32:37
+ 2 2 kthreadd 0.18 2.82 2026-05-27T13:32:37
+ 11 11 kworker/0:1 1.42 2.76 2026-05-27T13:32:36
+ 39 39 kworker/u20:0-a 0.10 2.71 2026-05-27T13:32:38
+ 17 17 rcu_exp_gp_kthr 0.25 2.65 2026-05-27T13:32:37
+ 66 66 kworker/u20:3-e 0.38 2.55 2026-05-27T13:32:37
+ 20 20 cpuhp/0 0.53 2.51 2026-05-27T13:32:37
+ 28 28 ksoftirqd/2 0.59 2.48 2026-05-27T13:32:37
+ 55 55 kworker/u19:1 0.88 2.42 2026-05-27T13:32:37
+ 13 13 kworker/R-mm_pe 1.18 2.35 2026-05-27T13:32:36
+ 54 54 kworker/3:1-eve 0.14 2.20 2026-05-27T13:32:38
--- a/tools/accounting/delaytop.c~delaytop-sort-by-max-delay-to-highlight-top-latency-processes
+++ a/tools/accounting/delaytop.c
@@ -295,6 +295,7 @@ static void usage(void)
" -C, --container=PATH Monitor the container at specified cgroup path\n"
" -s, --sort=FIELD Sort by delay field (default: cpu)\n"
" -t, --type=FIELD Display only specified delay type with avg/max/timestamp\n"
+ " (rows sorted by MAX for that type, largest first)\n"
" -M, --memverbose Display memory detailed information\n");
exit(0);
}
@@ -838,6 +839,15 @@ static void get_task_delays(void)
closedir(dir);
}
+static void field_delay_max_and_ts(const struct task_info *task,
+ const struct field_desc *field,
+ unsigned long long *max_ns,
+ struct __kernel_timespec *max_ts);
+static void get_field_delay_values(const struct task_info *task,
+ const struct field_desc *field,
+ double *avg_ms, double *max_ms,
+ struct __kernel_timespec *max_ts);
+
/* Calculate average delay in milliseconds */
static double average_ms(unsigned long long total, unsigned long long count)
{
@@ -850,7 +860,7 @@ static double average_ms(unsigned long l
* Format __kernel_timespec to human readable string (YYYY-MM-DDTHH:MM:SS)
* Returns formatted string or "N/A" if timestamp is zero
*/
-static const char *format_timespec64(struct __kernel_timespec *ts)
+static const char *format_kernel_timespec(struct __kernel_timespec *ts)
{
static char buffer[32];
time_t time_sec;
@@ -891,6 +901,16 @@ static int compare_tasks(const void *a,
unsigned long long count1;
unsigned long long count2;
double avg1, avg2;
+ unsigned long long max1, max2;
+
+ /* -t/--type: default sort by MAX column for the selected type (descending) */
+ if (cfg.display_mode == MODE_TYPE && cfg.type_field) {
+ field_delay_max_and_ts(t1, cfg.type_field, &max1, NULL);
+ field_delay_max_and_ts(t2, cfg.type_field, &max2, NULL);
+ if (max1 != max2)
+ return max2 > max1 ? 1 : -1;
+ return 0;
+ }
total1 = *(unsigned long long *)((char *)t1 + cfg.sort_field->total_offset);
total2 = *(unsigned long long *)((char *)t2 + cfg.sort_field->total_offset);
@@ -905,6 +925,28 @@ static int compare_tasks(const void *a,
return 0;
}
+/* Max delay (ns) and timestamp for field (shared by display and sort) */
+static void field_delay_max_and_ts(const struct task_info *task, const struct field_desc *field,
+ unsigned long long *max_ns, struct __kernel_timespec *max_ts)
+{
+ if (!field || !field->max_offset) {
+ *max_ns = 0;
+ if (max_ts)
+ memset(max_ts, 0, sizeof(*max_ts));
+ return;
+ }
+
+ *max_ns = *(unsigned long long *)((char *)task + field->max_offset);
+
+ if (max_ts) {
+ if (field->max_ts_offset)
+ *max_ts = *(struct __kernel_timespec *)((char *)task +
+ field->max_ts_offset);
+ else
+ memset(max_ts, 0, sizeof(*max_ts));
+ }
+}
+
/* Get delay values for a specific field */
static void get_field_delay_values(const struct task_info *task, const struct field_desc *field,
double *avg_ms, double *max_ms,
@@ -923,13 +965,8 @@ static void get_field_delay_values(const
count = *(unsigned long long *)((char *)task + field->count_offset);
*avg_ms = average_ms(total, count);
- max = *(unsigned long long *)((char *)task + field->max_offset);
+ field_delay_max_and_ts(task, field, &max, max_ts);
*max_ms = (double)max / 1000000.0; /* Convert nanoseconds to milliseconds */
-
- if (field->max_ts_offset)
- *max_ts = *(struct __kernel_timespec *)((char *)task + field->max_ts_offset);
- else
- memset(max_ts, 0, sizeof(*max_ts));
}
/* Sort tasks by selected field */
@@ -1079,7 +1116,10 @@ static void display_results(int psi_ret)
}
/* Interacive command */
- suc &= BOOL_FPRINT(out, "[o]sort [M]memverbose [q]quit\n");
+ if (cfg.display_mode == MODE_TYPE && cfg.type_field)
+ suc &= BOOL_FPRINT(out, "[q]quit\n");
+ else
+ suc &= BOOL_FPRINT(out, "[o]sort [M]memverbose [q]quit\n");
if (sort_selected) {
if (cfg.display_mode == MODE_MEMVERBOSE)
suc &= BOOL_FPRINT(out,
@@ -1090,8 +1130,13 @@ static void display_results(int psi_ret)
}
/* Task delay output */
- suc &= BOOL_FPRINT(out, "Top %d processes (sorted by %s delay):\n",
- cfg.max_processes, get_name_by_field(cfg.sort_field));
+ if (cfg.display_mode == MODE_TYPE && cfg.type_field)
+ suc &= BOOL_FPRINT(out,
+ "Top %d processes (sorted by %s MAX delay, largest first):\n",
+ cfg.max_processes, get_name_by_field(cfg.type_field));
+ else
+ suc &= BOOL_FPRINT(out, "Top %d processes (sorted by %s delay):\n",
+ cfg.max_processes, get_name_by_field(cfg.sort_field));
if (cfg.display_mode == MODE_TYPE && cfg.type_field) {
/* Display mode for -t option: show only specified type with avg/max/timestamp */
@@ -1132,7 +1177,7 @@ static void display_results(int psi_ret)
&max_ms, &max_ts);
suc &= BOOL_FPRINT(out, "%12.2f %12.2f %20s\n",
- avg_ms, max_ms, format_timespec64(&max_ts));
+ avg_ms, max_ms, format_kernel_timespec(&max_ts));
} else if (cfg.display_mode == MODE_MEMVERBOSE) {
suc &= BOOL_FPRINT(out, DELAY_FMT_MEMVERBOSE,
TASK_AVG(tasks[i], mem),
@@ -1201,9 +1246,13 @@ static void handle_keypress(char ch, int
} else {
switch (ch) {
case 'o':
+ if (cfg.display_mode == MODE_TYPE)
+ break;
sort_selected = 1;
break;
case 'M':
+ if (cfg.display_mode == MODE_TYPE)
+ break;
toggle_display_mode();
for (field = sort_fields; field->name != NULL; field++) {
if (field->supported_modes & cfg.display_mode) {
--- a/tools/accounting/getdelays.c~delaytop-sort-by-max-delay-to-highlight-top-latency-processes
+++ a/tools/accounting/getdelays.c
@@ -235,6 +235,11 @@ static const char *format_timespec(struc
if (ts->tv_sec == 0 && ts->tv_nsec == 0)
return "N/A";
+ /* Avoid Y2038 truncation on 32-bit platforms */
+ if (sizeof(time_sec) < sizeof(ts->tv_sec) &&
+ ts->tv_sec > (__u64)((1ULL << (sizeof(time_sec) * 8 - 1)) - 1))
+ return "N/A";
+
time_sec = ts->tv_sec;
/* Use thread-safe localtime_r */
_
Patches currently in -mm which might be from wang.yaxin@zte.com.cn are
delaytop-add-delay-max-for-delaytop.patch
delaytop-add-timestamp-of-delay-max.patch
delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch added to mm-nonmm-unstable branch
@ 2026-10-31 1:06 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-10-31 1:06 UTC (permalink / raw)
To: mm-commits, yang.yang29, xu.xin, thomas.weissschuh, fan.yu9,
corbet, wang.yaxin, akpm
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 14722 bytes --]
The patch titled
Subject: delaytop: sort by max delay to highlight top latency processes
has been added to the -mm mm-nonmm-unstable branch. Its filename is
delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: Wang Yaxin <wang.yaxin@zte.com.cn>
Subject: delaytop: sort by max delay to highlight top latency processes
Date: Wed, 23 Sep 2026 21:05:42 +0800
When using -t/--type option, sort tasks by the maximum delay value of
the selected type in descending order (largest delay first).
This enables quickly identifying the top N processes with the highest
delay spikes, which is essential for diagnosing latency problems by
pinpointing which processes contributed most to system delays.
Link: https://lore.kernel.org/20260923210542517bP5gb_zEY1jsriLQHagUT@zte.com.cn
Signed-off-by: Wang Yaxin <wang.yaxin@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Fan Yu <fan.yu9@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xu Xin <xu.xin@linux.dev>
---
Documentation/accounting/delay-accounting.rst | 87 +++++++++++-----
tools/accounting/delaytop.c | 71 +++++++++++--
tools/accounting/getdelays.c | 8 +
3 files changed, 133 insertions(+), 33 deletions(-)
--- a/Documentation/accounting/delay-accounting.rst~delaytop-sort-by-max-delay-to-highlight-top-latency-processes
+++ a/Documentation/accounting/delay-accounting.rst
@@ -152,28 +152,28 @@ Basic usage with default settings (sorts
IRQ full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
[o]sort [M]memverbose [q]quit
Top 20 processes (sorted by cpu delay):
- PID TGID COMMAND CPU(ms) IO(ms) IRQ(ms) MEM(ms)
+ PID TGID COMMAND CPU(ms) IO(ms) IRQ(ms) MEM(ms)
------------------------------------------------------------------------
- 110 110 kworker/15:0H-s 27.91 0.00 0.00 0.00
- 57 57 cpuhp/7 3.18 0.00 0.00 0.00
- 99 99 cpuhp/14 2.97 0.00 0.00 0.00
- 51 51 cpuhp/6 0.90 0.00 0.00 0.00
- 44 44 kworker/4:0H-sy 0.80 0.00 0.00 0.00
- 60 60 ksoftirqd/7 0.74 0.00 0.00 0.00
- 76 76 idle_inject/10 0.31 0.00 0.00 0.00
- 100 100 idle_inject/14 0.30 0.00 0.00 0.00
- 1309 1309 systemsettings 0.29 0.00 0.00 0.00
- 45 45 cpuhp/5 0.22 0.00 0.00 0.00
- 63 63 cpuhp/8 0.20 0.00 0.00 0.00
- 87 87 cpuhp/12 0.18 0.00 0.00 0.00
- 93 93 cpuhp/13 0.17 0.00 0.00 0.00
- 1265 1265 acpid 0.17 0.00 0.00 0.00
- 1552 1552 sshd 0.17 0.00 0.00 0.00
- 2584 2584 sddm-helper 0.16 0.00 0.00 0.00
- 1284 1284 rtkit-daemon 0.15 0.00 0.00 0.00
- 1326 1326 nde-netfilter 0.14 0.00 0.00 0.00
- 27 27 cpuhp/2 0.13 0.00 0.00 0.00
- 631 631 kworker/11:2-rc 0.11 0.00 0.00 0.00
+ 110 110 kworker/15:0H-s 27.91 0.00 0.00 0.00
+ 57 57 cpuhp/7 3.18 0.00 0.00 0.00
+ 99 99 cpuhp/14 2.97 0.00 0.00 0.00
+ 51 51 cpuhp/6 0.90 0.00 0.00 0.00
+ 44 44 kworker/4:0H-sy 0.80 0.00 0.00 0.00
+ 60 60 ksoftirqd/7 0.74 0.00 0.00 0.00
+ 76 76 idle_inject/10 0.31 0.00 0.00 0.00
+ 100 100 idle_inject/14 0.30 0.00 0.00 0.00
+ 1309 1309 systemsettings 0.29 0.00 0.00 0.00
+ 45 45 cpuhp/5 0.22 0.00 0.00 0.00
+ 63 63 cpuhp/8 0.20 0.00 0.00 0.00
+ 87 87 cpuhp/12 0.18 0.00 0.00 0.00
+ 93 93 cpuhp/13 0.17 0.00 0.00 0.00
+ 1265 1265 acpid 0.17 0.00 0.00 0.00
+ 1552 1552 sshd 0.17 0.00 0.00 0.00
+ 2584 2584 sddm-helper 0.16 0.00 0.00 0.00
+ 1284 1284 rtkit-daemon 0.15 0.00 0.00 0.00
+ 1326 1326 nde-netfilter 0.14 0.00 0.00 0.00
+ 27 27 cpuhp/2 0.13 0.00 0.00 0.00
+ 631 631 kworker/11:2-rc 0.11 0.00 0.00 0.00
Interactive keyboard controls during runtime::
@@ -181,7 +181,7 @@ Interactive keyboard controls during run
M - Toggle display mode (Default/Memory Verbose)
q - Quit
-Available sort fields(use -s/--sort or interactive command)::
+Available sort fields (use -s/--sort or interactive command)::
cpu(c) - CPU delay
blkio(i) - I/O delay
@@ -212,3 +212,46 @@ Advanced usage examples::
# ./delaytop -d secs
Specify refresh interval as secs
+
+ # ./delaytop -t type
+ Display only specified delay type with avg/max/timestamp
+ (rows sorted by MAX for that type, largest first)
+
+
+
+delaytop add delay_max fields to track the maximum delay value for each delay
+type (cpu, blkio, irq, swapin, freepages, thrashing, compact, wpcopy) per task::
+
+ bash# ./delaytop -t cpu
+ System Pressure Information: (avg10/avg60/avg300/total)
+ CPU some: 0.4%/ 0.2%/ 0.1%/ 220(ms)
+ CPU full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ Memory full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ Memory some: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ IO full: 0.0%/ 0.0%/ 0.0%/ 12(ms)
+ IO some: 0.0%/ 0.0%/ 0.0%/ 13(ms)
+ IRQ full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
+ [q]quit
+ Top 20 processes (sorted by cpu MAX delay, largest first):
+ PID TGID COMMAND AVG(ms) MAX(ms) MAX_TIMESTAMP
+ ------------------------------------------------------------------------
+ 9 9 kworker/0:0-eve 0.59 16.87 2026-05-27T13:32:39
+ 30 30 kworker/2:0H-kb 2.87 11.36 2026-05-27T13:32:36
+ 27 27 migration/2 1.05 9.51 2026-05-27T13:32:37
+ 50 50 kworker/2:1-eve 0.50 9.13 2026-05-27T13:32:37
+ 15 15 rcu_preempt 0.11 8.98 2026-05-27T13:32:37
+ 1 1 init 0.17 7.12 2026-05-27T13:32:38
+ 67 67 scsi_eh_0 1.20 4.23 2026-05-27T13:32:37
+ 23 23 ksoftirqd/1 1.12 3.77 2026-05-27T13:32:36
+ 3 3 pool_workqueue 0.72 3.55 2026-05-27T13:32:38
+ 62 62 kworker/u20:2-a 0.49 3.03 2026-05-27T13:32:37
+ 2 2 kthreadd 0.18 2.82 2026-05-27T13:32:37
+ 11 11 kworker/0:1 1.42 2.76 2026-05-27T13:32:36
+ 39 39 kworker/u20:0-a 0.10 2.71 2026-05-27T13:32:38
+ 17 17 rcu_exp_gp_kthr 0.25 2.65 2026-05-27T13:32:36
+ 66 66 kworker/u20:3-e 0.38 2.55 2026-05-27T13:32:37
+ 20 20 cpuhp/0 0.53 2.51 2026-05-27T13:32:38
+ 28 28 ksoftirqd/2 0.59 2.48 2026-05-27T13:32:36
+ 55 55 kworker/u19:1 0.88 2.42 2026-05-27T13:32:36
+ 13 13 kworker/R-mm_pe 1.18 2.35 2026-05-27T13:32:36
+ 54 54 kworker/3:1-eve 0.14 2.20 2026-05-27T13:32:38
--- a/tools/accounting/delaytop.c~delaytop-sort-by-max-delay-to-highlight-top-latency-processes
+++ a/tools/accounting/delaytop.c
@@ -295,6 +295,7 @@ static void usage(void)
" -C, --container=PATH Monitor the container at specified cgroup path\n"
" -s, --sort=FIELD Sort by delay field (default: cpu)\n"
" -t, --type=FIELD Display only specified delay type with avg/max/timestamp\n"
+ " (rows sorted by MAX for that type, largest first)\n"
" -M, --memverbose Display memory detailed information\n");
exit(0);
}
@@ -838,6 +839,15 @@ static void get_task_delays(void)
closedir(dir);
}
+static void field_delay_max_and_ts(const struct task_info *task,
+ const struct field_desc *field,
+ unsigned long long *max_ns,
+ struct __kernel_timespec *max_ts);
+static void get_field_delay_values(const struct task_info *task,
+ const struct field_desc *field,
+ double *avg_ms, double *max_ms,
+ struct __kernel_timespec *max_ts);
+
/* Calculate average delay in milliseconds */
static double average_ms(unsigned long long total, unsigned long long count)
{
@@ -850,7 +860,7 @@ static double average_ms(unsigned long l
* Format __kernel_timespec to human readable string (YYYY-MM-DDTHH:MM:SS)
* Returns formatted string or "N/A" if timestamp is zero
*/
-static const char *format_timespec64(struct __kernel_timespec *ts)
+static const char *format_kernel_timespec(struct __kernel_timespec *ts)
{
static char buffer[32];
time_t time_sec;
@@ -894,6 +904,16 @@ static int compare_tasks(const void *a,
unsigned long long count1;
unsigned long long count2;
double avg1, avg2;
+ unsigned long long max1, max2;
+
+ /* -t/--type: default sort by MAX column for the selected type (descending) */
+ if (cfg.display_mode == MODE_TYPE && cfg.type_field) {
+ field_delay_max_and_ts(t1, cfg.type_field, &max1, NULL);
+ field_delay_max_and_ts(t2, cfg.type_field, &max2, NULL);
+ if (max1 != max2)
+ return max2 > max1 ? 1 : -1;
+ return 0;
+ }
total1 = *(unsigned long long *)((char *)t1 + cfg.sort_field->total_offset);
total2 = *(unsigned long long *)((char *)t2 + cfg.sort_field->total_offset);
@@ -908,6 +928,28 @@ static int compare_tasks(const void *a,
return 0;
}
+/* Max delay (ns) and timestamp for field (shared by display and sort) */
+static void field_delay_max_and_ts(const struct task_info *task, const struct field_desc *field,
+ unsigned long long *max_ns, struct __kernel_timespec *max_ts)
+{
+ if (!field || !field->max_offset) {
+ *max_ns = 0;
+ if (max_ts)
+ memset(max_ts, 0, sizeof(*max_ts));
+ return;
+ }
+
+ *max_ns = *(unsigned long long *)((char *)task + field->max_offset);
+
+ if (max_ts) {
+ if (field->max_ts_offset)
+ *max_ts = *(struct __kernel_timespec *)((char *)task +
+ field->max_ts_offset);
+ else
+ memset(max_ts, 0, sizeof(*max_ts));
+ }
+}
+
/* Get delay values for a specific field */
static void get_field_delay_values(const struct task_info *task, const struct field_desc *field,
double *avg_ms, double *max_ms,
@@ -926,13 +968,8 @@ static void get_field_delay_values(const
count = *(unsigned long long *)((char *)task + field->count_offset);
*avg_ms = average_ms(total, count);
- max = *(unsigned long long *)((char *)task + field->max_offset);
+ field_delay_max_and_ts(task, field, &max, max_ts);
*max_ms = (double)max / 1000000.0; /* Convert nanoseconds to milliseconds */
-
- if (field->max_ts_offset)
- *max_ts = *(struct __kernel_timespec *)((char *)task + field->max_ts_offset);
- else
- memset(max_ts, 0, sizeof(*max_ts));
}
/* Sort tasks by selected field */
@@ -1082,7 +1119,10 @@ static void display_results(int psi_ret)
}
/* Interacive command */
- suc &= BOOL_FPRINT(out, "[o]sort [M]memverbose [q]quit\n");
+ if (cfg.display_mode == MODE_TYPE && cfg.type_field)
+ suc &= BOOL_FPRINT(out, "[q]quit\n");
+ else
+ suc &= BOOL_FPRINT(out, "[o]sort [M]memverbose [q]quit\n");
if (sort_selected) {
if (cfg.display_mode == MODE_MEMVERBOSE)
suc &= BOOL_FPRINT(out,
@@ -1093,8 +1133,13 @@ static void display_results(int psi_ret)
}
/* Task delay output */
- suc &= BOOL_FPRINT(out, "Top %d processes (sorted by %s delay):\n",
- cfg.max_processes, get_name_by_field(cfg.sort_field));
+ if (cfg.display_mode == MODE_TYPE && cfg.type_field)
+ suc &= BOOL_FPRINT(out,
+ "Top %d processes (sorted by %s MAX delay, largest first):\n",
+ cfg.max_processes, get_name_by_field(cfg.type_field));
+ else
+ suc &= BOOL_FPRINT(out, "Top %d processes (sorted by %s delay):\n",
+ cfg.max_processes, get_name_by_field(cfg.sort_field));
if (cfg.display_mode == MODE_TYPE && cfg.type_field) {
/* Display mode for -t option: show only specified type with avg/max/timestamp */
@@ -1135,7 +1180,7 @@ static void display_results(int psi_ret)
&max_ms, &max_ts);
suc &= BOOL_FPRINT(out, " %12.2f %12.2f %20s\n",
- avg_ms, max_ms, format_timespec64(&max_ts));
+ avg_ms, max_ms, format_kernel_timespec(&max_ts));
} else if (cfg.display_mode == MODE_MEMVERBOSE) {
suc &= BOOL_FPRINT(out, DELAY_FMT_MEMVERBOSE,
TASK_AVG(tasks[i], mem),
@@ -1204,9 +1249,13 @@ static void handle_keypress(char ch, int
} else {
switch (ch) {
case 'o':
+ if (cfg.display_mode == MODE_TYPE)
+ break;
sort_selected = 1;
break;
case 'M':
+ if (cfg.display_mode == MODE_TYPE)
+ break;
toggle_display_mode();
for (field = sort_fields; field->name != NULL; field++) {
if (field->supported_modes & cfg.display_mode) {
--- a/tools/accounting/getdelays.c~delaytop-sort-by-max-delay-to-highlight-top-latency-processes
+++ a/tools/accounting/getdelays.c
@@ -235,6 +235,14 @@ static const char *format_timespec(struc
if (ts->tv_sec == 0 && ts->tv_nsec == 0)
return "N/A";
+ /* Avoid Y2038 truncation on 32-bit platforms */
+ if (sizeof(time_sec) < sizeof(ts->tv_sec)) {
+ __s64 max = (__s64)((1ULL << (sizeof(time_sec) * 8 - 1)) - 1);
+
+ if (ts->tv_sec > max || ts->tv_sec < -max - 1)
+ return "N/A";
+ }
+
time_sec = ts->tv_sec;
/* Use thread-safe localtime_r */
_
Patches currently in -mm which might be from wang.yaxin@zte.com.cn are
delaytop-add-delay-max-for-delaytop.patch
delaytop-add-timestamp-of-delay-max.patch
delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-10-31 1:06 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-10-31 1:06 + delaytop-sort-by-max-delay-to-highlight-top-latency-processes.patch added to mm-nonmm-unstable branch Andrew Morton
-- strict thread matches above, loose matches on Subject: below --
2026-07-02 23:02 Andrew Morton
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.