[RTEMS Project] #2271: Improved timestamp implementation

RTEMS trac trac at rtems.org
Mon Mar 16 16:18:07 UTC 2015

#2271: Improved timestamp implementation
 Reporter:  sebastian.huber  |       Owner:  sebastian.huber
     Type:  enhancement      |      Status:  accepted
 Priority:  normal           |   Milestone:  4.11.1
Component:  cpukit           |     Version:  4.11
 Severity:  normal           |  Resolution:
 Keywords:                   |

Comment (by AlexKrEB):

 Plots with hardware periphery (NGMP)

 These plots as well as those in the upcoming section feature the same test
 environment than previously, however, a NGMP 4 processor core board was
 used. Profiling was enabled and the frequency was 50MHz.


 The bintime plot shows a linear increase in requests which nearly
 quadruples from 600000 requests for one processor to nearly 2.2 million
 requests for four processors.
 For the RTEMSUptime it also starts to grow linearly, however with four
 processors a breakdown can be investigated. This behaviour in supposed to
 continue once more processors are in use or the frequency increases. For
 one processor there are about 120000 requests and the peak is reached for
 three processors with 250000.

 '''Plots without hardware periphery (NGMP)'''


 For the cases without hardware periphery the plot figures are similar to
 the behaviour described in the section before. For the bintime requests,
 the increase is again linear, whereas the increase drops for the RTEMS
 nanosecond extension when four processors are used. Altogether the
 absolute amount of requests in higher than in the case of hardware usage
 due to the simplified return logic.

Ticket URL: <http://devel.rtems.org/ticket/2271#comment:6>
RTEMS Project <http://www.rtems.org/>
RTEMS Project

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