hello community ,
I upgraded my kernel version from 3.xx to 5.10, but I've noticed a performance degradation.
test in kernel 3.12 :
time dd if=/dev/zero count=1024000 bs=1 of=/tmp/v
1024000+0 records in
1024000+0 records out
real 0m 16.65s
user 0m 1.49s
sys 0m 14.95s
test in kernel 5.10 :
$ time dd if=/dev/zero count=1024000 bs=1 of=/tmp/v
1024000+0 records in
1024000+0 records out
real 0m 50.31s
user 0m 2.92s
sys 0m 42.94s
does anyone know the problem ?
Welcome!
3 times slower is surpring indeed.
bs=1 causes many context switches.
How is bs=512?
@nakach , hmm, did you run this once / 1000 times ? was /tmp full/empty/busy was your host busy ...,
if a slowdown was of such a magnitude I guess there'd would've been plenty of noise within the wider community.
I presume you are referring to a linux kernel here ?
5.10 is coming on for ~4yrs old , could you upgrade to a later version ?
is your h/ware also ageing well ....
I haven't personally experienced this problem but a quick search tells me that you are not alone. There is loads available to read online.
For reference my search criteria was:
Search engine: Google
Keywords: "Linux kernel 5.10 performance"