From: David Miller <davem@davemloft.net>
To: rostedt@goodmis.org
Cc: linux-kernel@vger.kernel.org, mrubin@google.com, dhsharp@google.com
Subject: Re: [PATCH 04/15] ftrace: pack event structures.
Date: Tue, 08 Mar 2011 22:39:51 -0800 (PST) [thread overview]
Message-ID: <20110308.223951.193722389.davem@davemloft.net> (raw)
In-Reply-To: <1299627003.20306.94.camel@gandalf.stny.rr.com>
From: Steven Rostedt <rostedt@goodmis.org>
Date: Tue, 08 Mar 2011 18:30:03 -0500
> I'm going back through this patch set and looking to incorporate it into
> 2.6.39. But I know how touchy sparc is with "packed" data structures. Do
> you see this patch as hurting sparc?
>
> I wonder if we should change this to something like:
>
> #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
> # define do_event_packed __attirbute__((packed))
> #else
> # define do_event_packed
> #endif
>
> and use "do_event_packed" instead?
I think you should elide packed at all costs, and instead tell the compiler
what your intentions are by exposing the real types using unions or
similar instead of hiding it in an opaque way behind final char[] arrays.
next prev parent reply other threads:[~2011-03-09 6:39 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-04 0:13 [Patch 00/15] Reduce tracing payload size David Sharp
2010-12-04 0:13 ` [PATCH 01/15] tracing: Add a 'buffer_overwrite' debugfs file David Sharp
2010-12-04 1:57 ` Steven Rostedt
2010-12-08 20:15 ` David Sharp
2010-12-08 21:46 ` [PATCH] tracing: Add an 'overwrite' trace_option David Sharp
2010-12-14 0:39 ` David Sharp
2011-03-09 0:45 ` David Sharp
2011-03-11 9:45 ` [tip:perf/core] " tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 02/15] ring_buffer.c: Remove unused #include <linux/trace_irq.h> David Sharp
2011-03-11 9:46 ` [tip:perf/core] ring-buffer: " tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 03/15] ring_buffer: Align buffer_page struct allocations only to fit the flags David Sharp
2010-12-04 1:43 ` Steven Rostedt
2010-12-07 22:44 ` David Sharp
2010-12-04 0:13 ` [PATCH 04/15] ftrace: pack event structures David Sharp
2011-03-08 23:30 ` Steven Rostedt
2011-03-09 1:09 ` Steven Rostedt
2011-03-09 6:39 ` David Miller [this message]
2011-03-09 15:18 ` Steven Rostedt
2011-03-10 23:21 ` David Sharp
2011-03-11 3:37 ` Steven Rostedt
2011-03-09 13:01 ` Steven Rostedt
2010-12-04 0:13 ` [PATCH 05/15] ftrace: fix event alignment: ftrace:context_switch and ftrace:wakeup David Sharp
2011-03-11 9:48 ` [tip:perf/core] tracing: Fix " tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 06/15] ftrace: fix event alignment: module:module_request David Sharp
2010-12-04 1:47 ` Steven Rostedt
2010-12-06 1:28 ` Li Zefan
2011-03-11 9:48 ` [tip:perf/core] tracing: Fix " tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 07/15] ftrace: fix event alignment: kvm:kvm_hv_hypercall David Sharp
2010-12-04 1:49 ` Steven Rostedt
2010-12-04 8:11 ` Avi Kivity
2010-12-06 20:38 ` David Sharp
2010-12-07 9:22 ` Avi Kivity
2010-12-07 21:16 ` David Sharp
2010-12-08 9:18 ` Avi Kivity
2011-03-08 23:55 ` Steven Rostedt
2011-03-09 8:50 ` Avi Kivity
2011-03-09 12:54 ` Steven Rostedt
2011-03-09 13:01 ` Avi Kivity
2011-03-11 9:49 ` [tip:perf/core] tracing: Fix " tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 08/15] ftrace: fix event alignment: mce:mce_record David Sharp
2010-12-04 1:50 ` Steven Rostedt
2010-12-09 13:33 ` Frederic Weisbecker
2011-03-11 9:49 ` [tip:perf/core] tracing: Fix " tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 09/15] ftrace: fix event alignment: skb:kfree_skb David Sharp
2010-12-04 1:52 ` Steven Rostedt
2010-12-04 13:38 ` Neil Horman
2011-03-11 9:50 ` [tip:perf/core] tracing: Fix " tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 10/15] ftrace: fix event alignment: jbd2:* David Sharp
2010-12-04 1:52 ` Steven Rostedt
2011-03-09 0:03 ` Steven Rostedt
2011-03-09 0:31 ` Ted Ts'o
2011-03-09 0:41 ` Steven Rostedt
2010-12-04 0:13 ` [PATCH 11/15] ftrace: fix event alignment: ext4:* David Sharp
2010-12-04 1:53 ` Steven Rostedt
2011-03-09 0:04 ` Steven Rostedt
2010-12-04 0:13 ` [PATCH 12/15] trace_output.c: adjust conditional expression formatting David Sharp
2011-03-11 9:50 ` [tip:perf/core] tracing: Adjust conditional expression latency formatting tip-bot for David Sharp
2010-12-04 0:13 ` [PATCH 13/15] small_traces: Add config option to shrink trace events David Sharp
2010-12-04 1:56 ` Steven Rostedt
2010-12-04 2:33 ` David Sharp
2010-12-04 2:54 ` Steven Rostedt
2010-12-09 14:55 ` Frederic Weisbecker
2010-12-09 15:08 ` Steven Rostedt
2010-12-09 15:28 ` Frederic Weisbecker
2010-12-09 16:16 ` Mathieu Desnoyers
2011-03-09 0:23 ` Steven Rostedt
2010-12-04 0:13 ` [PATCH 14/15] small_traces: Remove trace output of large fields David Sharp
2010-12-04 0:13 ` [PATCH 15/15] small_traces: Remove 8 bytes from trace_entry David Sharp
2010-12-06 13:22 ` [Patch 00/15] Reduce tracing payload size Andi Kleen
2010-12-06 13:56 ` Ted Ts'o
2010-12-06 14:58 ` Andi Kleen
2010-12-06 16:17 ` Steven Rostedt
2010-12-06 16:31 ` Miguel Ojeda
2010-12-06 16:41 ` Andi Kleen
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