On Fri, 2013-05-10 at 20:50 +1000, Michael Neuling wrote:
> The buffer is in the core (not main memory) and hence only has limited
> entries. So skipping entries that can hopefully be determined in
> other ways means we can log more branches.
>
> That being said, it's a PITA for the kernel ;-)
I
On Fri, May 10, 2013 at 8:43 PM, Peter Zijlstra wrote:
> On Thu, May 09, 2013 at 08:39:15AM +1000, Michael Neuling wrote:
>> > Just because I'm curious.. however does that happen? Surely the CPU
>> > knows where next to fetch instructions?
>>
>> For computed gotos (ie. branch to a register value),
On Thu, May 09, 2013 at 08:39:15AM +1000, Michael Neuling wrote:
> > Just because I'm curious.. however does that happen? Surely the CPU
> > knows where next to fetch instructions?
>
> For computed gotos (ie. branch to a register value), the hardware gives
> you the from and to address in the bran
On Thu, 2013-05-09 at 08:45 +1000, Michael Neuling wrote:
> Stephane Eranian wrote:
>
> > On Wed, May 8, 2013 at 5:59 PM, Peter Zijlstra wrote:
> > > On Tue, May 07, 2013 at 11:35:28AM +1000, Michael Neuling wrote:
> > >> Peter & Stephane,
> > >>
> > >> We are plumbing the POWER8 Branch History
Stephane Eranian wrote:
> On Wed, May 8, 2013 at 5:59 PM, Peter Zijlstra wrote:
> > On Tue, May 07, 2013 at 11:35:28AM +1000, Michael Neuling wrote:
> >> Peter & Stephane,
> >>
> >> We are plumbing the POWER8 Branch History Rolling Buffer (BHRB) into
> >> struct perf_branch_entry.
> >>
> >> Some
Peter Zijlstra wrote:
> On Tue, May 07, 2013 at 11:35:28AM +1000, Michael Neuling wrote:
> > Peter & Stephane,
> >
> > We are plumbing the POWER8 Branch History Rolling Buffer (BHRB) into
> > struct perf_branch_entry.
> >
> > Sometimes on POWER8 we may not be able to fill out the "to" address.
On Wed, May 8, 2013 at 5:59 PM, Peter Zijlstra wrote:
> On Tue, May 07, 2013 at 11:35:28AM +1000, Michael Neuling wrote:
>> Peter & Stephane,
>>
>> We are plumbing the POWER8 Branch History Rolling Buffer (BHRB) into
>> struct perf_branch_entry.
>>
>> Sometimes on POWER8 we may not be able to fill
On Tue, May 07, 2013 at 11:35:28AM +1000, Michael Neuling wrote:
> Peter & Stephane,
>
> We are plumbing the POWER8 Branch History Rolling Buffer (BHRB) into
> struct perf_branch_entry.
>
> Sometimes on POWER8 we may not be able to fill out the "to" address.
Just because I'm curious.. however
Peter & Stephane,
We are plumbing the POWER8 Branch History Rolling Buffer (BHRB) into
struct perf_branch_entry.
Sometimes on POWER8 we may not be able to fill out the "to" address. We
initially thought of just making this 0, but it's feasible that this
could be a valid address to branch to.
T
