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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-20 11:41:01 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-20 11:41:01 +0300 |
commit | f4484d138b31e8fa1ba410363b5b9664f68974af (patch) | |
tree | 6d776b1212604d3b16df499ae6e455e4a20544db /Documentation | |
parent | 1d1df41c5a33359a00e919d54eaebfb789711fdc (diff) | |
parent | b1e78ef3be2533973953a35a56739fda7325875c (diff) | |
download | linux-f4484d138b31e8fa1ba410363b5b9664f68974af.tar.xz |
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
"55 patches.
Subsystems affected by this patch series: percpu, procfs, sysctl,
misc, core-kernel, get_maintainer, lib, checkpatch, binfmt, nilfs2,
hfs, fat, adfs, panic, delayacct, kconfig, kcov, and ubsan"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (55 commits)
lib: remove redundant assignment to variable ret
ubsan: remove CONFIG_UBSAN_OBJECT_SIZE
kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR
lib/Kconfig.debug: make TEST_KMOD depend on PAGE_SIZE_LESS_THAN_256KB
btrfs: use generic Kconfig option for 256kB page size limit
arch/Kconfig: split PAGE_SIZE_LESS_THAN_256KB from PAGE_SIZE_LESS_THAN_64KB
configs: introduce debug.config for CI-like setup
delayacct: track delays from memory compact
Documentation/accounting/delay-accounting.rst: add thrashing page cache and direct compact
delayacct: cleanup flags in struct task_delay_info and functions use it
delayacct: fix incomplete disable operation when switch enable to disable
delayacct: support swapin delay accounting for swapping without blkio
panic: remove oops_id
panic: use error_report_end tracepoint on warnings
fs/adfs: remove unneeded variable make code cleaner
FAT: use io_schedule_timeout() instead of congestion_wait()
hfsplus: use struct_group_attr() for memcpy() region
nilfs2: remove redundant pointer sbufs
fs/binfmt_elf: use PT_LOAD p_align values for static PIE
const_structs.checkpatch: add frequently used ops structs
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/accounting/delay-accounting.rst | 55 |
1 files changed, 27 insertions, 28 deletions
diff --git a/Documentation/accounting/delay-accounting.rst b/Documentation/accounting/delay-accounting.rst index 1b8b46deeb29..197fe319cbec 100644 --- a/Documentation/accounting/delay-accounting.rst +++ b/Documentation/accounting/delay-accounting.rst @@ -13,6 +13,8 @@ a) waiting for a CPU (while being runnable) b) completion of synchronous block I/O initiated by the task c) swapping in pages d) memory reclaim +e) thrashing page cache +f) direct compact and makes these statistics available to userspace through the taskstats interface. @@ -41,11 +43,12 @@ generic data structure to userspace corresponding to per-pid and per-tgid statistics. The delay accounting functionality populates specific fields of this structure. See - include/linux/taskstats.h + include/uapi/linux/taskstats.h for a description of the fields pertaining to delay accounting. It will generally be in the form of counters returning the cumulative -delay seen for cpu, sync block I/O, swapin, memory reclaim etc. +delay seen for cpu, sync block I/O, swapin, memory reclaim, thrash page +cache, direct compact etc. Taking the difference of two successive readings of a given counter (say cpu_delay_total) for a task will give the delay @@ -88,41 +91,37 @@ seen. General format of the getdelays command:: - getdelays [-t tgid] [-p pid] [-c cmd...] - + getdelays [-dilv] [-t tgid] [-p pid] Get delays, since system boot, for pid 10:: - # ./getdelays -p 10 + # ./getdelays -d -p 10 (output similar to next case) Get sum of delays, since system boot, for all pids with tgid 5:: - # ./getdelays -t 5 - - - CPU count real total virtual total delay total - 7876 92005750 100000000 24001500 - IO count delay total - 0 0 - SWAP count delay total - 0 0 - RECLAIM count delay total - 0 0 + # ./getdelays -d -t 5 + print delayacct stats ON + TGID 5 -Get delays seen in executing a given simple command:: - # ./getdelays -c ls / + CPU count real total virtual total delay total delay average + 8 7000000 6872122 3382277 0.423ms + IO count delay total delay average + 0 0 0ms + SWAP count delay total delay average + 0 0 0ms + RECLAIM count delay total delay average + 0 0 0ms + THRASHING count delay total delay average + 0 0 0ms + COMPACT count delay total delay average + 0 0 0ms - bin data1 data3 data5 dev home media opt root srv sys usr - boot data2 data4 data6 etc lib mnt proc sbin subdomain tmp var +Get IO accounting for pid 1, it works only with -p:: + # ./getdelays -i -p 1 + printing IO accounting + linuxrc: read=65536, write=0, cancelled_write=0 - CPU count real total virtual total delay total - 6 4000250 4000000 0 - IO count delay total - 0 0 - SWAP count delay total - 0 0 - RECLAIM count delay total - 0 0 +The above command can be used with -v to get more debug information. |