[ltt-dev] [BUG] [PATCH] LTTV - interrupt handler time calculation is wrong in case of nested interrupts

[Mathieu Desnoyers]

Integrated in lttv-0.11.2-15102008. Thanks !

Mathieu

* Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
> Hi Gaurav,
> 
> Your fix seems appropriate, I'll merge it.
> 
> Thanks !
> 
> Mathieu
> 
> * Gaurav Singh (gausinghnsit at gmail.com) wrote:
> > Hi all,
> > 
> > I was using the interrupt handler plugin and noticed that sometimes
> > the timer interrupt  handler was taking a lot of time. Specifically
> > the max time indicated by the plugin was wrong. This was because the
> > time calculated by the plugin in case of nested interrupts is wrong.
> > 
> > Nested interrupt:
> > Interrupt 1 (entry)  .... 1
> > Interrupt 2(entry).....2
> > Interrupt 2 (exit) ..... 3
> > Interrupt 3 (exit) ..... 4
> > 
> > The plugin did the following calculation:
> > Time for 1st interrupt = timeat (3) - timeat (1)
> > Time for 2nd interrupt = timeat (4) - timeat (2)
> > 
> > 
> > The following patch corrects this anamoly. Basically it takes the up
> > the most recent interrupt and pairs the irq_exit with it. Please check
> > if this works for you.
> > 
> > diff -uprN lttv-0.10.0-pre11-10032008/lttv/modules/gui/interrupts/interrupts.c
> > ../lttv-0.10.0-pre11-10032008/lttv/modules/gui/interrupts/interrupts.c
> > --- lttv-0.10.0-pre11-10032008/lttv/modules/gui/interrupts/interrupts.c
> > 2007-10-16 06:44:40.000000000 +0530
> > +++ ../lttv-0.10.0-pre11-10032008/lttv/modules/gui/interrupts/interrupts.c
> >      2008-09-29 15:13:02.000000000 +0530
> > @@ -583,7 +583,7 @@ static void CalculateData(LttTime time_e
> >    LttTime duration;
> >    GArray *FirstRequestIrqExit = event_data->FirstRequestIrqExit;
> >    GArray *FirstRequestIrqEntry = event_data->FirstRequestIrqEntry;
> > -  for(i = 0; i < FirstRequestIrqEntry->len; i++)
> > +  for(i = FirstRequestIrqEntry->len-1; i >=0; i--)
> >    {
> >      element = &g_array_index(FirstRequestIrqEntry,irq_entry,i);
> >      if(element->cpu_id == cpu_id)
> > 
> > 
> > 
> > Regards,
> > Gaurav
> > 
> 
> -- 
> Mathieu Desnoyers
> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
> 
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-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68