Maksytka/linux
1
1
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-11-30 23:16:01 +07:00
Code Issues Packages Projects Releases Wiki Activity

docs: update delaytop documentation for new interactive features

Browse Source 
This commit updates the delaytop documentation to reflect the newly
added features:
1) Added comprehensive description of interactive keyboard controls
2) Documented all available sort fields
3) Added examples for advanced usage scenarios
4) Included PSI availability note

Link: https://lkml.kernel.org/r/20250907001457696qAqUGGkV1VfEO6OkVMovW@zte.com.cn
Signed-off-by: Fan Yu <fan.yu9@zte.com.cn>
Reviewed-by: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Fan Yu
2025-09-07 00:14:57 +08:00
committed by Andrew Morton
parent 0c10f9cd81
commit c25822ccaa
1 changed files with 57 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

89
Documentation/accounting/delay-accounting.rst
View File

@@ -134,47 +134,72 @@ The above command can be used with -v to get more debug information.
After the system starts, use `delaytop` to get the system-wide delay information,
which includes system-wide PSI information and Top-N high-latency tasks.
Note: PSI support requires `CONFIG_PSI=y` and `psi=1` for full functionality.
`delaytop` supports sorting by CPU latency in descending order by default,
displays the top 20 high-latency tasks by default, and refreshes the latency
data every 2 seconds by default.
`delaytop` is an interactive tool for monitoring system pressure and task delays.
It supports multiple sorting options, display modes, and real-time keyboard controls.
Get PSI information and Top-N tasks delay, since system boot::
Basic usage with default settings (sorts by CPU delay, shows top 20 tasks, refreshes every 2 seconds)::
bash# ./delaytop
System Pressure Information: (avg10/avg60/avg300/total)
CPU some: 0.0%/ 0.0%/ 0.0%/ 345(ms)
System Pressure Information: (avg10/avg60vg300/total)
CPU some: 0.0%/ 0.0%/ 0.0%/ 106137(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%/ 65(ms)
IO some: 0.0%/ 0.0%/ 0.0%/ 79(ms)
IO full: 0.0%/ 0.0%/ 0.0%/ 2240(ms)
IO some: 0.0%/ 0.0%/ 0.0%/ 2783(ms)
IRQ full: 0.0%/ 0.0%/ 0.0%/ 0(ms)
Top 20 processes (sorted by CPU delay):
PID TGID COMMAND CPU(ms) IO(ms) SWAP(ms) RCL(ms) THR(ms) CMP(ms) WP(ms) IRQ(ms)
----------------------------------------------------------------------------------------------
161 161 zombie_memcg_re 1.40 0.00 0.00 0.00 0.00 0.00 0.00 0.00
130 130 blkcg_punt_bio 1.37 0.00 0.00 0.00 0.00 0.00 0.00 0.00
444 444 scsi_tmf_0 0.73 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1280 1280 rsyslogd 0.53 0.04 0.00 0.00 0.00 0.00 0.00 0.00
12 12 ksoftirqd/0 0.47 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1277 1277 nbd-server 0.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00
308 308 kworker/2:2-sys 0.41 0.00 0.00 0.00 0.00 0.00 0.00 0.00
55 55 netns 0.36 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1187 1187 acpid 0.31 0.03 0.00 0.00 0.00 0.00 0.00 0.00
6184 6184 kworker/1:2-sys 0.24 0.00 0.00 0.00 0.00 0.00 0.00 0.00
186 186 kaluad 0.24 0.00 0.00 0.00 0.00 0.00 0.00 0.00
18 18 ksoftirqd/1 0.24 0.00 0.00 0.00 0.00 0.00 0.00 0.00
185 185 kmpath_rdacd 0.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00
190 190 kstrp 0.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2759 2759 agetty 0.20 0.03 0.00 0.00 0.00 0.00 0.00 0.00
1190 1190 kworker/0:3-sys 0.19 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1272 1272 sshd 0.15 0.04 0.00 0.00 0.00 0.00 0.00 0.00
1156 1156 license 0.15 0.11 0.00 0.00 0.00 0.00 0.00 0.00
134 134 md 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00
6142 6142 kworker/3:2-xfs 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00
[o]sort [M]memverbose [q]quit
Top 20 processes (sorted by cpu delay):
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
Dynamic interactive interface of delaytop::
Interactive keyboard controls during runtime::
o - Select sort field (CPU, IO, IRQ, Memory, etc.)
M - Toggle display mode (Default/Memory Verbose)
q - Quit
Available sort fields(use -s/--sort or interactive command)::
cpu(c) - CPU delay
blkio(i) - I/O delay
irq(q) - IRQ delay
mem(m) - Total memory delay
swapin(s) - Swapin delay (memory verbose mode only)
freepages(r) - Freepages reclaim delay (memory verbose mode only)
thrashing(t) - Thrashing delay (memory verbose mode only)
compact(p) - Compaction delay (memory verbose mode only)
wpcopy(w) - Write page copy delay (memory verbose mode only)
Advanced usage examples::
# ./delaytop -s blkio
Sorted by IO delay
# ./delaytop -s mem -M
Sorted by memory delay in memory verbose mode
# ./delaytop -p pid
Print delayacct stats