On 11/2/2020 6:02 PM, Michal Hocko wrote:
On Mon 02-11-20 17:53:14, Rong Chen wrote:
On 11/2/20 5:27 PM, Michal Hocko wrote:
On Mon 02-11-20 17:15:43, kernel test robot wrote:
Greeting,
FYI, we noticed a -22.7% regression of will-it-scale.per_process_ops due to
commit:
commit: bd0b230fe14554bfffbae54e19038716f96f5a41 ("mm/memcg: unify swap and memsw
page counters")
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
I really fail to see how this can be anything else than a data structure
layout change. There is one counter less.
btw. are cgroups configured at all? What would be the configuration?
Hi Michal,
We used the default configure of cgroups, not sure what configuration you
want,
could you give me more details? and here is the cgroup info of will-it-scale
process:
$ cat /proc/3042/cgroup
12:hugetlb:/
11:memory:/system.slice/lkp-bootstrap.service
OK, this means that memory controler is enabled and in use. Btw. do you
get the original performance if you add one phony page_counter after the
union?
I add one phony page_counter after the union and re-test, the regression
reduced to -1.2%. It looks like the regression caused by the data
structure layout change.
=========================================================================================
tbox_group/testcase/rootfs/kconfig/compiler/nr_task/mode/test/cpufreq_governor/ucode/debug-setup:
lkp-hsw-4ex1/will-it-scale/debian-10.4-x86_64-20200603.cgz/x86_64-rhel-8.3/gcc-9/50%/process/page_fault2/performance/0x16/test1
commit:
8d387a5f172f26ff8c76096d5876b881dec6b7ce
bd0b230fe14554bfffbae54e19038716f96f5a41
b3233916ab0a883e1117397e28b723bd0e4ac1eb (debug patch add one phony
page_counter after the union)
8d387a5f172f26ff bd0b230fe14554bfffbae54e190 b3233916ab0a883e1117397e28b
---------------- --------------------------- ---------------------------
%stddev %change %stddev %change %stddev
\ | \ | \
187632 -22.8% 144931 -1.2% 185391
will-it-scale.per_process_ops
13509525 -22.8% 10435073 -1.2% 13348181
will-it-scale.workload
--
Zhengjun Xing