Re: [PATCH 1/2] perf: Correctly align perf event tracing buffer

[Frederic Weisbecker]

On Mon, Mar 29, 2010 at 10:51:31AM +0200, Peter Zijlstra wrote:
> On Sun, 2010-03-28 at 07:11 +0200, Frederic Weisbecker wrote:
> >  kernel/trace/trace_event_perf.c |   11 +++++++++--
> >  1 files changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
> > index 0709e4f..69941f3 100644
> > --- a/kernel/trace/trace_event_perf.c
> > +++ b/kernel/trace/trace_event_perf.c
> > @@ -15,7 +15,12 @@ EXPORT_PER_CPU_SYMBOL_GPL(perf_trace_regs);
> >  static char *perf_trace_buf;
> >  static char *perf_trace_buf_nmi;
> >  
> > -typedef typeof(char [PERF_MAX_TRACE_SIZE]) perf_trace_t ;
> > +/*
> > + * Force it to be aligned to unsigned long to avoid misaligned accesses
> > + * suprises
> > + */
> > +typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
> > +	perf_trace_t;
> >  
> 
> wouldn't __aligned(8) be simpler?


David and Tejun seemed to prefer to create the alignment on the
type level rather than using an align.

I'm personally fine either way.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/