* Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote: > On Sun, 6 Dec 2009 02:26:06 +0100 > "Rafael J. Wysocki" <rjw@xxxxxxx> wrote: > > > On Sunday 06 December 2009, Arjan van de Ven wrote: > > > On Sun, 6 Dec 2009 00:55:36 +0100 > > > "Rafael J. Wysocki" <rjw@xxxxxxx> wrote: > > > > > > > > > > > Disk spinup/spindown takes time, but also some ACPI devices resume > > > > slowly, serio devices do that too and there are surprisingly many > > > > drivers that wait (using msleep() during suspend and resume). > > > > Apart from this, every PCI device going from D0 to D3 during > > > > suspend and from D3 to D0 during resume requires us to sleep for > > > > 10 ms (the sleeping is done by the PCI core, so the drivers don't > > > > even realize its there). > > > > > > maybe a good step is to make a scripts/bootgraph.pl equivalent for > > > suspend/resume (or make a debug mode that outputs in a compatible > > > format so that the script can be used as is.. I don't mind either > > > way, and consider this my offer to help with such a script as long > > > as there's sufficient logging in dmesg ;-) > > > > OK, so what kind of logging is needed? > > basically the equivalent of the two initcall_debug paths in > > init/main.c:do_one_initcall() > > which prints a start time and an end time (and a pid) for each init > function; if we have the same for suspend calls (and resume)... we can > make the tool graph it. > > Would be nice to get markers for start and end of the whole suspend > sequence as well as for the resume sequence; those make it easier to > know when the end is (so that the axis can be drawn etc) > > shouldn't be too hard to implement... I think an even better option would be to extend 'perf timechart' to be suspend/resume aware: add a few tracepoint events and teach 'perf timechart' to draw them. (We should be able to do perf timechart record across suspend/resume cycles just fine.) ( Doing that would also improve the tracing facilities within suspend/resume quite significantly. It wouldnt just be a single-purpose thing for graphing, but perf trace and perf stat would work equally well. ) Thanks, Ingo _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
