Hi Eric, On Wed, Nov 13, 2019 at 06:33:44AM -0800, Eric Dumazet wrote: > On Wed, Nov 13, 2019 at 2:35 AM Feng Tang wrote: > > > > Hi Eric, > > > > On Fri, Nov 08, 2019 at 04:35:13PM +0800, kernel test robot wrote: > > > Greeting, > > > > > > FYI, we noticed a -37.9% regression of apachebench.requests_per_second due to commit: > > > > > > commit: 19f92a030ca6d772ab44b22ee6a01378a8cb32d4 ("net: increase SOMAXCONN to 4096") > > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > > > Any thought on this? The test is actually: > > > > sysctl -w net.ipv4.tcp_syncookies=0 > > > I have no plan trying to understand why anyone would disable syncookies . > This is a non starter really, since this makes a server vulnerable to > a trivial DOS attack. > Thanks for the prompt response. This sysctl change was added to work around one old error when running the apachebench. The error was "apr_socket_recv: Connection reset by peer (104)" I just removed the sysctl setting of "ipv4.tcp_synccookies" and re-run the same benchmark in 0day, the regression is still there. Thanks, Feng > > Since the test changes a sysctl, you also can change other sysctls if > you really need to show a ' number of transactions' for a particular > benchmark. > > The change on SOMAXCONN was driven by a security issue, and security > comes first. > > > > enable_apache_mod auth_basic authn_core authn_file authz_core authz_host authz_user access_compat > > systemctl restart apache2 > > ab -k -q -t 300 -n 1000000 -c 4000 127.0.0.1/ > > > > And some info about apachebench result is: > > > > w/o patch: > > > > Connection Times (ms) > > min mean[+/-sd] median max > > Connect: 0 0 19.5 0 7145 > > Processing: 0 4 110.0 3 21647 > > Waiting: 0 2 92.4 1 21646 > > Total: 0 4 121.1 3 24762 > > > > w/ patch: > > > > Connection Times (ms) > > min mean[+/-sd] median max > > Connect: 0 0 43.2 0 7143 > > Processing: 0 19 640.4 3 38708 > > Waiting: 0 24 796.5 1 38708 > > Total: 0 19 657.5 3 39725 > > > > > > Thanks, > > Feng > > > > > > > > in testcase: apachebench > > > on test machine: 16 threads Intel(R) Xeon(R) CPU D-1541 @ 2.10GHz with 48G memory > > > with following parameters: > > > > > > runtime: 300s > > > concurrency: 4000 > > > cluster: cs-localhost > > > cpufreq_governor: performance > > > ucode: 0x7000019 > > > > > > test-description: apachebench is a tool for benchmarking your Apache Hypertext Transfer Protocol (HTTP) server. > > > test-url: https://httpd.apache.org/docs/2.4/programs/ab.html > > > > > > In addition to that, the commit also has significant impact on the following tests: > > > > > > +------------------+------------------------------------------------------------------+ > > > | testcase: change | apachebench: apachebench.requests_per_second -37.5% regression | > > > | test machine | 16 threads Intel(R) Xeon(R) CPU D-1541 @ 2.10GHz with 48G memory | > > > | test parameters | cluster=cs-localhost | > > > | | concurrency=8000 | > > > | | cpufreq_governor=performance | > > > | | runtime=300s | > > > | | ucode=0x7000019 | > > > +------------------+------------------------------------------------------------------+ > > > > > > > > > If you fix the issue, kindly add following tag > > > Reported-by: kernel test robot > > > > > > > > > Details are as below: > > > --------------------------------------------------------------------------------------------------> > > > > > > > > > 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 > > > > > > ========================================================================================= > > > cluster/compiler/concurrency/cpufreq_governor/kconfig/rootfs/runtime/tbox_group/testcase/ucode: > > > cs-localhost/gcc-7/4000/performance/x86_64-rhel-7.6/debian-x86_64-2019-09-23.cgz/300s/lkp-bdw-de1/apachebench/0x7000019 > > > > > > commit: > > > 6d6f0383b6 ("netdevsim: Fix use-after-free during device dismantle") > > > 19f92a030c ("net: increase SOMAXCONN to 4096") > > > > > > 6d6f0383b697f004 19f92a030ca6d772ab44b22ee6a > > > ---------------- --------------------------- > > > %stddev %change %stddev > > > \ | \ > > > 22640 ± 4% +71.1% 38734 apachebench.connection_time.processing.max > > > 24701 +60.9% 39743 apachebench.connection_time.total.max > > > 22639 ± 4% +71.1% 38734 apachebench.connection_time.waiting.max > > > 24701 +15042.0 39743 apachebench.max_latency.100% > > > 40454 -37.9% 25128 apachebench.requests_per_second > > > 25.69 +58.8% 40.79 apachebench.time.elapsed_time > > > 25.69 +58.8% 40.79 apachebench.time.elapsed_time.max > > > 79.00 -37.0% 49.75 apachebench.time.percent_of_cpu_this_job_got > > > 98.88 +61.0% 159.18 apachebench.time_per_request > > > 434631 -37.9% 269889 apachebench.transfer_rate > > > 1.5e+08 ± 18% +109.5% 3.141e+08 ± 27% cpuidle.C3.time > > > 578957 ± 7% +64.1% 949934 ± 12% cpuidle.C3.usage > > > 79085 ± 4% +24.8% 98720 meminfo.AnonHugePages > > > 41176 +14.2% 47013 meminfo.PageTables > > > 69429 -34.9% 45222 meminfo.max_used_kB > > > 63.48 +12.7 76.15 mpstat.cpu.all.idle% > > > 2.42 ± 2% -0.9 1.56 mpstat.cpu.all.soft% > > > 15.30 -5.2 10.13 mpstat.cpu.all.sys% > > > 18.80 -6.6 12.16 mpstat.cpu.all.usr% > > > 65.00 +17.7% 76.50 vmstat.cpu.id > > > 17.00 -35.3% 11.00 vmstat.cpu.us > > > 7.00 ± 24% -50.0% 3.50 ± 14% vmstat.procs.r > > > 62957 -33.3% 42012 vmstat.system.cs > > > 33174 -1.4% 32693 vmstat.system.in