Re: [mm] e6e88712e4: stress-ng.tmpfs.ops_per_sec -69.7% regression

From: Rong Chen
Date: Mon Nov 02 2020 - 00:22:37 EST




On 10/30/20 10:58 PM, Matthew Wilcox wrote:
On Fri, Oct 30, 2020 at 10:02:45PM +0800, Chen, Rong A wrote:
On 10/30/2020 9:17 PM, Matthew Wilcox wrote:
On Fri, Oct 30, 2020 at 03:17:15PM +0800, kernel test robot wrote:
Details are as below:
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To reproduce:

git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
bin/lkp install job.yaml # job file is attached in this email
bin/lkp run job.yaml
Do you actually test these instructions before you send them out?

hdd_partitions: "/dev/disk/by-id/ata-WDC_WD2500BEKT-00PVMT0_WD-WX11A23L4840-part
1"
ssd_partitions: "/dev/nvme1n1p1 /dev/nvme0n1p1"
rootfs_partition: "/dev/disk/by-id/ata-INTEL_SSDSC2CW240A3_CVCV204303WP240CGN-part1"

That's _very_ specific to a given machine. I'm not familiar with
this test, so I don't know what I need to change.

Hi Matthew,

Sorry about that, I copied the job.yaml file from the server,
the right way to do is to set your disk partitions in the yaml,
please see https://github.com/intel/lkp-tests#run-your-own-disk-partitions.

there is another reproduce script attached in the original mail
for your reference.
Can you reproduce this? Here's my results:

# stress-ng "--timeout" "100" "--times" "--verify" "--metrics-brief" "--sequential" "96" "--class" "memory" "--minimize" "--exclude" "spawn,exec,swap,stack,atomic,bad-altstack,bsearch,context,full,heapsort,hsearch,judy,lockbus,lsearch,malloc,matrix-3d,matrix,mcontend,membarrier,memcpy,memfd,memrate,memthrash,mergesort,mincore,null,numa,pipe,pipeherd,qsort,radixsort,remap,resources,rmap,shellsort,skiplist,stackmmap,str,stream,tlb-shootdown,tree,tsearch,vm-addr,vm-rw,vm-segv,vm,wcs,zero,zlib"
stress-ng: info: [7670] disabled 'oom-pipe' as it may hang or reboot the machine (enable it with the --pathological option)
stress-ng: info: [7670] dispatching hogs: 96 tmpfs
stress-ng: info: [7670] successful run completed in 100.23s (1 min, 40.23 secs)
stress-ng: info: [7670] stressor bogo ops real time usr time sys time bogo ops/s bogo ops/s
stress-ng: info: [7670] (secs) (secs) (secs) (real time) (usr+sys time)
stress-ng: info: [7670] tmpfs 8216 100.10 368.02 230.89 82.08 13.72
stress-ng: info: [7670] for a 100.23s run time:
stress-ng: info: [7670] 601.38s available CPU time
stress-ng: info: [7670] 368.71s user time ( 61.31%)
stress-ng: info: [7670] 231.55s system time ( 38.50%)
stress-ng: info: [7670] 600.26s total time ( 99.81%)
stress-ng: info: [7670] load average: 78.32 27.87 10.10


Hi Matthew,

IIUC, yes, we can reproduce it, here is the result from the server:

$ stress-ng --timeout 100 --times --verify --metrics-brief --sequential 96 --class memory --minimize --exclude spawn,exec,swap,stack,atomic,bad-altstack,bsearch,context,full,heapsort,hsearch,judy,lockbus,lsearch,malloc,matrix-3d,matrix,mcontend,membarrier,memcpy,memfd,memrate,memthrash,mergesort,mincore,null,numa,pipe,pipeherd,qsort,radixsort,remap,resources,rmap,shellsort,skiplist,stackmmap,str,stream,tlb-shootdown,tree,tsearch,vm-addr,vm-rw,vm-segv,vm,wcs,zero,zlib
stress-ng: info:  [2765] disabled 'oom-pipe' as it may hang or reboot the machine (enable it with the --pathological option)
stress-ng: info:  [2765] dispatching hogs: 96 tmpfs
stress-ng: info:  [2765] successful run completed in 104.67s (1 min, 44.67 secs)
stress-ng: info:  [2765] stressor       bogo ops real time  usr time  sys time   bogo ops/s   bogo ops/s
stress-ng: info:  [2765]                           (secs) (secs)    (secs)   (real time) (usr+sys time)
stress-ng: info:  [2765] tmpfs               363    103.02 622.07   7289.85         3.52         0.05
stress-ng: info:  [2765] for a 104.67s run time:
stress-ng: info:  [2765]   10047.98s available CPU time
stress-ng: info:  [2765]     622.46s user time   (  6.19%)
stress-ng: info:  [2765]    7290.66s system time ( 72.56%)
stress-ng: info:  [2765]    7913.12s total time  ( 78.75%)
stress-ng: info:  [2765] load average: 79.62 28.89 10.45

we compared the tmpfs.ops_per_sec: (363 / 103.02) between this commit and parent commit.

Best Regards,
Rong Chen