On Sat, Jun 28, 2014 at 12:08:39PM +0200, Palle Girgensohn wrote: > > > 27 jun 2014 kl. 18:34 skrev Konstantin Belousov <kostik...@gmail.com>: > > > On Fri, Jun 27, 2014 at 10:57:53AM -0400, John Baldwin wrote: > >> On Friday, June 27, 2014 8:56:13 am Konstantin Belousov wrote: > >>> Hi, > >>> I did some measurements and hacks to see about the performance and > >>> scalability of PostgreSQL 9.3 on FreeBSD, sponsored by The FreeBSD > >>> Foundation. > >>> > >>> The results are described in https://kib.kiev.ua/kib/pgsql_perf.pdf. > >>> The uncommitted patches, referenced in the article, are available as > >>> https://kib.kiev.ua/kib/pig1.patch.txt > >>> https://kib.kiev.ua/kib/patch-2 > >> > >> Did you run the same benchmark on the same hardware with any other OS's to > >> compare results? > > > > No. > > > > FWIW, before the failing after the 30 clients is corrected, I do not > > think it is much interesting to do such comparision. > > This is great work! > > Does anybody know how far back in FreeBSD versions using posix semaphore > instead of sysv would make a difference? It seems we need a rather current > version? 8.x did not support it at all, at some point at lest, and in 9 it > was buggy. I could add he patch-2 to the port, but I reckon it needs a > conditional based on FreeBSD version? > I recommend to add it as an option. The currently supported versions of stable/9 and higher have new posix semaphores implementation. The stable/8 also has posix semaphores, but there it is kernel-based interface, I do not plan to evaluate it in any way.
> The clang bug should go upstreams, right? I believe there is already some activity about it. I do not follow clang development. > > I have seen similar curves, presented by Greg Smith (PostgreSQL > hacker) where he concluded that there is no point in running more > than 50 concurrent connections. This was for Linux. In your measures, > the knee is at 30. That's said, FreeBSD could and should do better, > but probably there is a limit where there will be a knee in the graph > and performance will drop. It should be more than 30, though, as you > rightly commented. > > Do you any ideas to pursue this further apart from complicated > rewrites like DragonFly? > I do. The scope of the current work was done to obtain understanding where do we stay and, if possible, evaluate ideas, possibly in the hackish way. I hope and almost sure that this will be continued, but cannot provide any time estimation.
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