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Xiaobing Li 3fcb9d1720 io_uring/sqpoll: statistics of the true utilization of sq threads
Count the running time and actual IO processing time of the sqpoll
thread, and output the statistical data to fdinfo.

Variable description:
"work_time" in the code represents the sum of the jiffies of the sq
thread actually processing IO, that is, how many milliseconds it
actually takes to process IO. "total_time" represents the total time
that the sq thread has elapsed from the beginning of the loop to the
current time point, that is, how many milliseconds it has spent in
total.

The test tool is fio, and its parameters are as follows:
[global]
ioengine=io_uring
direct=1
group_reporting
bs=128k
norandommap=1
randrepeat=0
refill_buffers
ramp_time=30s
time_based
runtime=1m
clocksource=clock_gettime
overwrite=1
log_avg_msec=1000
numjobs=1

[disk0]
filename=/dev/nvme0n1
rw=read
iodepth=16
hipri
sqthread_poll=1

The test results are as follows:
Every 2.0s: cat /proc/9230/fdinfo/6 | grep -E Sq
SqMask: 0x3
SqHead: 3197153
SqTail: 3197153
CachedSqHead:   3197153
SqThread:       9231
SqThreadCpu:    11
SqTotalTime:    18099614
SqWorkTime:     16748316

The test results corresponding to different iodepths are as follows:
|-----------|-------|-------|-------|------|-------|
|   iodepth |   1   |   4   |   8   |  16  |  64   |
|-----------|-------|-------|-------|------|-------|
|utilization| 2.9%  | 8.8%  | 10.9% | 92.9%| 84.4% |
|-----------|-------|-------|-------|------|-------|
|    idle   | 97.1% | 91.2% | 89.1% | 7.1% | 15.6% |
|-----------|-------|-------|-------|------|-------|

Signed-off-by: Xiaobing Li <xiaobing.li@samsung.com>
Link: https://lore.kernel.org/r/20240228091251.543383-1-xiaobing.li@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-01 06:28:19 -07:00
arch IOMMU Fixes for Linux v6.8-rc2 2024-02-02 12:43:51 -08:00
block block: Fix where bio IO priority gets set 2024-02-01 11:00:06 -07:00
certs
crypto
Documentation USB driver fixes for 6.8-rc3 2024-02-04 06:52:29 +00:00
drivers Char/Misc driver fixes for 6.8-rc3 2024-02-04 07:01:39 +00:00
fs Add do_ftruncate that truncates a struct file 2024-02-09 08:57:56 -07:00
include io_uring/kbuf: flag request if buffer pool is empty after buffer pick 2024-02-27 11:52:45 -07:00
init Kconfig: Disable -Wstringop-overflow for GCC globally 2024-02-01 14:57:17 -08:00
io_uring io_uring/sqpoll: statistics of the true utilization of sq threads 2024-03-01 06:28:19 -07:00
ipc
kernel Tracing and eventfs fixes for v6.8: 2024-02-02 15:32:58 -08:00
lib linux_kselftest-kunit-fixes-6.8-rc3 2024-01-30 15:12:58 -08:00
LICENSES
mm 22 hotfixes. 11 are cc:stable and the remainder address post-6.7 issues 2024-01-29 17:12:16 -08:00
net net: add napi_busy_loop_rcu() 2024-02-09 10:01:09 -08:00
rust
samples samples/cgroup: add .gitignore file for generated samples 2024-01-24 11:52:40 -08:00
scripts Kbuild fixes for v6.8 2024-02-01 11:57:42 -08:00
security lsm/stable-6.8 PR 20240131 2024-02-01 10:00:28 -08:00
sound ASoC: Fixes for v6.8 2024-02-01 19:40:42 +01:00
tools perf tools fixes for v6.8: 2024-02-03 12:52:36 +00:00
usr
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COPYING
CREDITS MAINTAINERS: supplement of zswap maintainers update 2024-01-25 23:52:21 -08:00
Kbuild
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MAINTAINERS MAINTAINERS update to point people to the new tree for i2c host driver 2024-02-04 06:47:45 +00:00
Makefile Linux 6.8-rc3 2024-02-04 12:20:36 +00:00
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Linux kernel
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