maybe you don't have a 127.0.0.1 lo interface, or you ar using owserver over a network with high latency (can be a high speed network but latency make everythink slow to start)
2011/1/23 Paul Alfille <[email protected]>: > Let me try that again: > > Your current setup is something like: > owget -> owserver -> bus master > > If you add another layer: > owget -> owserver -> owserver -> bus master > > you can see the effect of the owserver layer. > > OWFS doesn't care how many owserver layers you add, so adding several > layers might help seeing very small timing increments. > > For that matter, timing a single owget call may show more the effect > of starting the owget program and be very influenced by the filesystem > buffers. > > Here is an example: > > # 1 level owserver: > sudo /opt/owfs/bin/owserver -u -p 4401 > # time 100 directory listings > time \ > for x in 0 1 2 3 4 5 6 7 8 9 ; do for y in 0 1 2 3 4 5 6 7 8 9 ; do \ > /opt/owfs/bin/owdir -s 4401 /uncached > /dev/null ; \ > done ; done > > real 0m14.791s > user 0m0.010s > sys 0m0.030s > > # 10 level owserver: > sudo /opt/owfs/bin/owserver -u -p 4401 > /opt/owfs/bin/owserver -s 4401 -p 4402 > /opt/owfs/bin/owserver -s 4402 -p 4403 > /opt/owfs/bin/owserver -s 4403 -p 4404 > /opt/owfs/bin/owserver -s 4404 -p 4405 > /opt/owfs/bin/owserver -s 4405 -p 4406 > /opt/owfs/bin/owserver -s 4406 -p 4407 > /opt/owfs/bin/owserver -s 4407 -p 4408 > /opt/owfs/bin/owserver -s 4408 -p 4409 > /opt/owfs/bin/owserver -s 4409 -p 4410 > # again time 100 directory listings all through the 10 layers: > time \ > for x in 0 1 2 3 4 5 6 7 8 9 ; do for y in 0 1 2 3 4 5 6 7 8 9 ; do \ > /opt/owfs/bin/owdir -s 4410 /uncached > /dev/null ; \ > done ; done > > real 0m15.517s > user 0m0.000s > sys 0m0.050s > > Hence my point that it's the 1-wire bus, rather than owserver communication. > > To show the point even more dramatically, if we ask for the statistics > directory, which is all in memory, we get: > #1 layer > time \ > for x in 0 1 2 3 4 5 6 7 8 9 ; do for y in 0 1 2 3 4 5 6 7 8 9 ; do \ > /opt/owfs/bin/owdir -s 4401 /uncached/statistics > /dev/null ; \ > done ; done > > real 0m0.255s > user 0m0.020s > sys 0m0.010s > > #10 layers -- note that we have to ask for the distal bus specifically. > time \ > for x in 0 1 2 3 4 5 6 7 8 9 ; do for y in 0 1 2 3 4 5 6 7 8 9 ; do \ > /opt/owfs/bin/owdir -s 4410 > /uncached/bus.0/bus.0/bus.0/bus.0/bus.0/bus.0/bus.0/bus.0/bus.0/bus.0/statistics >> /dev/null ; \ > done ; done > > real 0m1.095s > user 0m0.000s > sys 0m0.040s > > Which adds about the same absolute overhead for owserver communication. > > Thus my conclusion that there may be delays or inefficiency in our > implementation, but it isn't owserver and you need to substract out > program (owget) setup time. > > Paul Alfille > > > > On Sun, Jan 23, 2011 at 12:39 PM, Guil Barros <[email protected]> wrote: >> Hi Paul, >> I'm not entirely sure what you mean, could you elaborate? >> >> Thanks, >> -Guil >> >> On Sun, Jan 23, 2011 at 6:11 AM, Paul Alfille <[email protected]> wrote: >>> On Sat, Jan 22, 2011 at 10:26 PM, Guil Barros <[email protected]> wrote: >>>> I am doing a number of reads with owget on individual DS18B20's and >>>> DS2438's and not quite getting the performance I expect: >>>> I assume this is at least partially overhead related to the owserver >>>> comms, is there a better way to handle multiple device access with the >>>> owshell commands? Anything I can do to speed things up otherwise? >>>> >>> >>> Can you test by going through 2 layers of owserver? That will show the >>> owserver overhead. Very small in my prior tests. >>> >>> ------------------------------------------------------------------------------ >>> Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! >>> Finally, a world-class log management solution at an even better price-free! >>> Download using promo code Free_Logger_4_Dev2Dev. Offer expires >>> February 28th, so secure your free ArcSight Logger TODAY! >>> http://p.sf.net/sfu/arcsight-sfd2d >>> _______________________________________________ >>> Owfs-developers mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/owfs-developers >>> >> >> ------------------------------------------------------------------------------ >> Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! >> Finally, a world-class log management solution at an even better price-free! >> Download using promo code Free_Logger_4_Dev2Dev. Offer expires >> February 28th, so secure your free ArcSight Logger TODAY! >> http://p.sf.net/sfu/arcsight-sfd2d >> _______________________________________________ >> Owfs-developers mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/owfs-developers >> > > ------------------------------------------------------------------------------ > Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! > Finally, a world-class log management solution at an even better price-free! > Download using promo code Free_Logger_4_Dev2Dev. Offer expires > February 28th, so secure your free ArcSight Logger TODAY! > http://p.sf.net/sfu/arcsight-sfd2d > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers > > -- Roberto Spadim Spadim Technology / SPAEmpresarial ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
