lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 10 Jul 2020 17:12:33 +0200 From: Willy Wolff <willy.mh.wolff.ml@...il.com> To: Lukasz Luba <lukasz.luba@....com> Cc: Chanwoo Choi <cw00.choi@...sung.com>, k.konieczny@...sung.com, krzk@...nel.org, kgene@...nel.org, s.nawrocki@...sung.com, b.zolnierkie@...sung.com, chanwoo@...nel.org, myungjoo.ham@...sung.com, kyungmin.park@...sung.com, linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org, linux-samsung-soc@...r.kernel.org, linux-arm-kernel@...ts.infradead.org Subject: Re: [RFC PATCH 0/2] PM / devfreq: Add delayed timer for polling Hi Lukasz, On 2020-07-08-15-25-03, Lukasz Luba wrote: > Hi Willy, > > On 7/3/20 1:33 PM, Willy Wolff wrote: > > Hi Chanwoo, > > > > I think it doesn't help on the benchmark I suggested that is doing only memory > > accesses. With both timer, I have the same timing. > > > > To test the benchmark with these new patches about timer: > > > > git clone https://github.com/wwilly/benchmark.git \ > > && cd benchmark \ > > && source env.sh \ > > && ./bench_build.sh \ > > && bash source/scripts/test_dvfs_mem_patched.sh > > > > The benchmark is set by default to run for 1s, but you can increase this by > > tweaking the script as: > > > > taskset 8 ./bench_install/bin/microbe_cache 33554431 0 9722222 <TIME in sec> ${little_freq} > > > > > > Also, as I reported the issue, would it be possible to add a > > Reported-by: Willy Wolff <willy.mh.wolff.ml@...il.com> ? > > Many thanks in advance. > > Thank you for your good work and the benchmark. I hope you will continue > to use it and report some issues. I am going to send a follow up patches > for the DMC and I will add your 'Reported-by'. In the tests I can see > the improvements, but it's worth to consult with you if I understand > the new results correctly. > Thanks for that. I will follow on the other patch thread discussion. > I think there is still some area for improvements in the devfreq and you > could find the interesting bits to contribute. In fact, this benchmark is motivated about part of my PhD research that has just been accepted at LCTES2020: "Performance Optimization on big.LITTLE Architectures: A Memory-latency Aware Approach" at https://dl.acm.org/doi/10.1145/3372799.3394370 Basically, it's about snooping latency with "bad" CPU DVFS choice on big.LITTLE systems or more generally SMP/AMP architecture. I'm cleaning up my code and will propose patches as an RFC later. It introduces a new CPU DVFS governor to limit snooping latency. Cheers, Willy > > Regards, > Lukasz > > > > > > > Best Regards, > > Willy > >
Powered by blists - more mailing lists