From: Michael Ellerman <michael@ellerman.id.au>
To: Vince Weaver <vince@deater.net>
Cc: Anton Blanchard <anton@au1.ibm.com>,
linux-kernel@vger.kernel.org,
Stephane Eranian <eranian@google.com>,
linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@samba.org>,
Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>,
Anshuman Khandual <khandual@linux.vnet.ibm.com>
Subject: Re: [PATCH 5/7] powerpc/perf: Define big-endian version of perf_mem_data_src
Date: Mon, 12 Aug 2013 09:57:58 +1000 [thread overview]
Message-ID: <20130811235758.GA29824@concordia> (raw)
In-Reply-To: <alpine.DEB.2.02.1308102232120.4119@pianoman.cluster.toy>
On Sat, Aug 10, 2013 at 10:34:58PM -0400, Vince Weaver wrote:
> On Sat, 10 Aug 2013, Sukadev Bhattiprolu wrote:
>
> >
> > include/uapi/linux/perf_event.h | 55 +++++++++++++++++++++++++++++++++++++++
> > 1 files changed, 55 insertions(+), 0 deletions(-)
>
> > +#define __PERF_LE 1234
> > +#define __PERF_BE 4321
> > +
> > +#if defined(__KERNEL__)
>
> I could be wrong, but I thought files under uapi weren't supposed to
> contain __KERNEL__ code. Wasn't that the whole point of uapi?
Yes.
> Also having the perf_event interface depend on endianess just seems like a
> complicated mess. Can't we just declare the interface to be a certain
> endianess and have the kernel byte-swap as necessary?
Yes I think so. The interface is already defined and it's little endian,
so on big endian we just need to swap.
The only part I'm not clear on is how things are handled in perf
userspace, it seems to already do some byte swapping.
cheers
next prev parent reply other threads:[~2013-08-11 23:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-10 17:48 [PATCH 0/7]: Enable 'perf mem' command for Power Sukadev Bhattiprolu
2013-08-10 17:49 ` [PATCH 1/7] powerpc/perf: Rename Power8 macros to start with PME Sukadev Bhattiprolu
2013-08-10 17:50 ` [PATCH 2/7] powerpc/perf: Export Power8 generic events in sysfs Sukadev Bhattiprolu
2013-08-10 17:50 ` [PATCH 3/7] powerpc/perf: Create mem-loads/mem-stores events for Power8 Sukadev Bhattiprolu
2013-08-10 17:51 ` [PATCH 4/7] powerpc/perf: Create mem-loads/mem-stores events for Power7 Sukadev Bhattiprolu
2013-08-10 17:51 ` [PATCH 5/7] powerpc/perf: Define big-endian version of perf_mem_data_src Sukadev Bhattiprolu
2013-08-11 2:34 ` Vince Weaver
2013-08-11 17:15 ` Sukadev Bhattiprolu
2013-08-11 23:57 ` Michael Ellerman [this message]
2013-08-12 3:19 ` Vince Weaver
2013-08-10 17:52 ` [PATCH 6/7] powerpc/perf: Export Power8 memory hierarchy info to user space Sukadev Bhattiprolu
2013-08-10 17:52 ` [PATCH 7/7] powerpc/perf: Export Power7 " Sukadev Bhattiprolu
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