Hello Josef, On 07/10/2015 02:08 PM, Josef Söntgen wrote: > Since the stats are absolute it would be best to reset them to zero > before collecting them a second time. In this case the rtc_drv should > not be in the top range anymore because it should not be used by vbox > while it is running but only once when it starts.
I collected another round of numbers that are non-cumulative for hw_x86_64 (not running on Muen). As before, the first measurement was done in the bootloader of the guest VM: pd_label | label | spent | % of total ---------------------+--------------+----------+----------- init -> virtualbox | EMT | 98001213 | 37.45505% init -> virtualbox | virtualbox | 83688021 | 31.98470% init -> rtc_drv | rtc_ep | 36408986 | 13.91514% init -> rtc_drv | rtc_drv | 23748123 | 9.07629% init | init | 4032147 | 1.54105% init -> acpi_drv | acpi_drv | 2543088 | 0.97194% init -> platform_drv | platform_drv | 2430257 | 0.92882% init -> ps2_drv | ps2_drv_ep | 1830875 | 0.69974% init -> timer | timer_drv_ep | 1654987 | 0.63252% init -> virtualbox | VMPwrUp | 1586461 | 0.60633% And here the second measurement once the Linux login prompt is visible: pd_label | label | spent | % of total -------------------+-------------------+------------+----------- init -> virtualbox | EMT | 1521043562 | 98.25379% init -> timer | timer_drv_ep | 19607895 | 1.26660% init -> virtualbox | Timer | 2819414 | 0.18212% init -> timer | timeout_scheduler | 1971086 | 0.12732% init -> virtualbox | alarm-timer | 1298777 | 0.08390% init -> virtualbox | ATA-1 | 525509 | 0.03395% core | pager_activation | 522312 | 0.03374% init -> fb_drv | vesa_ep | 181979 | 0.01176% core | entrypoint | 61660 | 0.00398% init -> virtualbox | OhciFramer | 15831 | 0.00102% So looking at these numbers the EMT thread is even more dominant and the rtc_drv is indeed gone: its spent/used figures of the second measurement are actually zero. >> I do not know the implementation details of rtc_drv but I did not expect >> it to make the top 10. > > I did not expect this either. Although it is indeed somewhat expensive > (i.e. it should be avoided to read it several times a second), I cannot > imagine why it takes about 10% of the total time when starting vbox. > It basically reads the time from the cmos which merely involves an IPC > to core to read the I/O port. It would be good to know if the number of > calls of the rtc_drv differ between base-hw and base-nova. Compared to the other work that is going on during startup I would have guessed that the rtc_drv had very little to do... Not quite sure if this could be a contributor to the timing inaccuracies that we observe on hw_x86_64_muen. There we have to specify kernel parameters notsc and lpj with a fixed value so Linux boots reliably. Regards, Adrian ------------------------------------------------------------------------------ Don't Limit Your Business. Reach for the Cloud. GigeNET's Cloud Solutions provide you with the tools and support that you need to offload your IT needs and focus on growing your business. Configured For All Businesses. Start Your Cloud Today. https://www.gigenetcloud.com/ _______________________________________________ genode-main mailing list genode-main@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/genode-main
