From: Ingo Molnar <mingo@elte.hu>
To: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perfcounters: fix type/event_id layout on big-endian systems
Date: Sat, 21 Mar 2009 10:42:46 +0100 [thread overview]
Message-ID: <20090321094246.GA5594@elte.hu> (raw)
In-Reply-To: <18884.29385.854691.357234@cargo.ozlabs.ibm.com>
* Paul Mackerras <paulus@samba.org> wrote:
> struct perf_counter_hw_event {
> union {
> +#ifndef __BIG_ENDIAN_BITFIELD
> struct {
> __u64 event_id : 56,
> type : 8;
> @@ -94,6 +96,16 @@ struct perf_counter_hw_event {
> __u64 raw_event_id : 63,
> raw_type : 1;
> };
> +#else
> + struct {
> + __u64 type : 8,
> + event_id : 56;
> + };
> + struct {
> + __u64 raw_type : 1,
> + raw_event_id : 63;
> + };
> +#endif /* __BIT_ENDIAN_BITFIELD */
hm, this ifdef really looks ugly. How about just changing event_id
to 64 bits and having a separate u32 type field? The size impact is
minimal, the cleanliness win is significant :-)
Ingo
next prev parent reply other threads:[~2009-03-21 9:43 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-21 4:53 [PATCH] perfcounters: fix type/event_id layout on big-endian systems Paul Mackerras
2009-03-21 9:42 ` Ingo Molnar [this message]
2009-03-21 9:52 ` Paul Mackerras
2009-03-21 9:56 ` Ingo Molnar
2009-03-21 11:41 ` Peter Zijlstra
2009-03-21 22:04 ` [PATCH] perf_counter: remove the event config bitfields Peter Zijlstra
2009-03-21 23:50 ` Paul Mackerras
2009-03-21 10:24 ` [PATCH] perfcounters: fix type/event_id layout on big-endian systems Peter Zijlstra
2009-03-21 12:08 ` Paul Mackerras
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