Hi Kai, Oops, fixed?
I just updated my system and tried to randomly download another game and it looks fine... Weird. Anyway, thanks for you guys. May the good code be with you. Danny On 2017-03-19 19:11, Kai Krakow <hurikha...@gmail.com> wrote: > Am Thu, 16 Mar 2017 14:04:14 +0800 > schrieb Danny YUE <sheepd...@gmail.com>: > >> Hi Kai, >> >> Thanks for your help :-) >> >> Code here: >> /usr/share/info $ cat /proc/sys/net/ipv4/tcp_fastopen >> 1 >> /usr/share/info $ cat /proc/sys/net/core/default_qdisc >> pfifo_fast >> /usr/share/info $ cat /proc/sys/net/ipv4/tcp_congestion_control >> cubic >> >> dnsmasq may help because...if my understanding is correct, Steam Linux >> client has a bug that it tries to query the DNS too often during >> downloading, then its request got throttled. Please see >> https://wiki.gentoo.org/wiki/Steam/Client_troubleshooting >> Section "Slow download speeds". > > This has been fixed with the March 9th 2017 Update. It's in the current > stable client. > >> For disk, I don't think it fits my case because for a downloading >> speed of 100KB/s, disk write should not be a bottleneck. > > Well, it still can be if there's a lot of data backlogged and the > writeback cache of the kernel is saturated. > >> I suspect it is related to Linux client because Steam Windows client >> on my machine downloads at the normal speed... > > This makes sense... However, here the linux client is downloading at 48 > mbytes/s which is pretty much the maximum of my 400 mbit link. > > So, if it is still slow for you, there seem to be other issues. > >> Well, I am not that familiar with network tuning things...so I will >> definitely check the methods you mentioned. > > Feel free to ask. > >> On 2017-03-15 21:07, Kai Krakow <hurikha...@gmail.com> wrote: >> > Am Wed, 15 Mar 2017 21:53:44 +0100 >> > schrieb Kai Krakow <hurikha...@gmail.com>: >> > >> >> Am Wed, 15 Mar 2017 21:24:10 +0800 >> >> schrieb Danny YUE <sheepd...@gmail.com>: >> >> >> [...] >> >> >> >> Here, it's downloading with peak bandwidths of 48 mbytes/s but >> >> usually it's around 38 mbytes/s. However, I sometimes see >> >> slowdowns, too. I guess that games are downloaded file by file, >> >> and when a lot of small files are left in the queue, it just >> >> cannot get good bandwidth. >> >> >> >> But I only see such slowdowns mostly short before the last few >> >> megabytes of a game. >> >> >> >> Could you check if your downloaded games consist of many smallish >> >> files? Then that could be the explanation. >> >> >> >> You could try activating fq_codel and tcp fastopen: >> >> >> >> In /proc/sys/net/ipv4/tcp_fastopen it should say 1. >> >> In /proc/sys/net/core/default_qdisc it should say fq_codel. >> >> >> >> Also, you may want to try out bbr congestion control: >> >> >> >> In /proc/sys/net/ipv4/tcp_congestion_control it should say bbr. >> >> >> >> By recompiling the kernel, you can reconfigure the defaults for >> >> this (and enable support). Some of these need modern kernels. >> >> >> >> Additionally, many small tcp request need a good portion of your >> >> upload bandwidth and are very dependent on good round trip times. >> >> Traditional DSL lines with ping times of 50-60ms can really slow >> >> down requests of small files a lot due to three-way tcp >> >> handshaking, that is, you could request only one smallish file per >> >> 100-120ms. This can totally destroy the usable bandwidth. Maybe >> >> watch a running ping while the downloads are running. If the ping >> >> times increase while the download slows down, your bottleneck is >> >> the upload. >> >> >> >> But also keep in mind that traditional spinning disks may not keep >> >> up with the bandwidth if confronted with many small files. If >> >> you're using SSD all should be fine. I'm running on bcache with >> >> writeback caching which gives a really good performance boost by >> >> adding a small SSD to one or more big HDDs. >> > >> > BTW: I don't see how dnsmasq could help you here... It can do >> > nothing about bandwidth. It only acts as a DNS cache which helps >> > keeping latency of the DNS resolver down. But this doesn't matter >> > here because during download, steam won't do many DNS requests. >> > >> > As already stated, part of the problem may be the upload, and/or bad >> > queue handling within your broadband router. You can work around it >> > with a traffic shaper and throttling upload below what's physically >> > possible with your internet line, thus keeping the queue in front >> > of the broadband router. That way, a traffic shaper could handle it >> > and work around bad queue handling. >> > >> > To resolve the issue it is important to sophistically test the >> > suggestions one step at a time, starting with the easy ones, and do >> > your measurements. >> >>
