diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/accounting/delay-accounting.rst | 91 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/kernel.rst | 2 | ||||
| -rw-r--r-- | Documentation/dev-tools/kcov.rst | 7 |
4 files changed, 66 insertions, 36 deletions
diff --git a/Documentation/accounting/delay-accounting.rst b/Documentation/accounting/delay-accounting.rst index 8ccc5af5ea1e..86d7902a657f 100644 --- a/Documentation/accounting/delay-accounting.rst +++ b/Documentation/accounting/delay-accounting.rst @@ -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 - -Dynamic interactive interface of delaytop:: + [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 + +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 diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index e019db1633fd..74ca438d2d6d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4603,7 +4603,7 @@ bit 2: print timer info bit 3: print locks info if CONFIG_LOCKDEP is on bit 4: print ftrace buffer - bit 5: replay all messages on consoles at the end of panic + bit 5: replay all kernel messages on consoles at the end of panic bit 6: print all CPUs backtrace (if available in the arch) bit 7: print only tasks in uninterruptible (blocked) state *Be aware* that this option may print a _lot_ of lines, diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 8b49eab937d0..f3ee807b5d8b 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -890,7 +890,7 @@ bit 1 print system memory info bit 2 print timer info bit 3 print locks info if ``CONFIG_LOCKDEP`` is on bit 4 print ftrace buffer -bit 5 replay all messages on consoles at the end of panic +bit 5 replay all kernel messages on consoles at the end of panic bit 6 print all CPUs backtrace (if available in the arch) bit 7 print only tasks in uninterruptible (blocked) state ===== ============================================ diff --git a/Documentation/dev-tools/kcov.rst b/Documentation/dev-tools/kcov.rst index 6611434e2dd2..8127849d40f5 100644 --- a/Documentation/dev-tools/kcov.rst +++ b/Documentation/dev-tools/kcov.rst @@ -361,7 +361,12 @@ local tasks spawned by the process and the global task that handles USB bus #1: */ sleep(2); - n = __atomic_load_n(&cover[0], __ATOMIC_RELAXED); + /* + * The load to the coverage count should be an acquire to pair with + * pair with the corresponding write memory barrier (smp_wmb()) on + * the kernel-side in kcov_move_area(). + */ + n = __atomic_load_n(&cover[0], __ATOMIC_ACQUIRE); for (i = 0; i < n; i++) printf("0x%lx\n", cover[i + 1]); if (ioctl(fd, KCOV_DISABLE, 0)) |