Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH V3 3/3] perf tools: Construct LBR call chain | Date | Tue, 18 Nov 2014 14:37:31 +0000 |
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> On Tue, Nov 18, 2014 at 03:13:50PM +0900, Namhyung Kim wrote: > > SNIP > > > >> > + * in "from" register, while the callee is > stored > > >> > + * in "to" register. > > >> > + * For example, there is a call stack > > >> > + * "A"->"B"->"C"->"D". > > >> > + * The LBR registers will recorde like > > >> > + * "C"->"D", "B"->"C", "A"->"B". > > >> > + * So only the first "to" register and all > "from" > > >> > + * registers are needed to construct the > whole > > >> stack. > > >> > + */ > > >> > > >> Andi is using some sanity checks: > > >> http://marc.info/?l=linux-kernel&m=141584447819894&w=2 > > >> I guess this could be applied in here, once his patch gets in. > > >> > > > > > > Are you suggesting me to remove the comments, or rebase the whole > > > patch to Andi's patch once it's merged? > > > > > > The branch history in Andi's patch is different as the call stack, > > > although they are both from LBR. > > > Andi's branch history recording branch records for taken branches, > > > interrupts, and exceptions. > > > While the LBR call stack records for the call stack. > > > > Right. And branch history can overlap with normal callchains so > > additional check in there is to remove duplication. While LBR call > > stack is separated to user only so there should be no overlap. > > hum, it seemed to me like the remove_loops function could be used for > this one as well.. but anyway I meant that this can be introduced later after > Andi's change gets in
I see. I will apply Andi's remove_loops.
Thanks, Kan
> > thanks, > jirka
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