From: Richard Kennedy <richard@rsk.demon.co.uk>
To: Steven Rostedt <rostedt@goodmis.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@redhat.com>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: [PATCH] trace: reorder struct ring_buffer_per_cpu to remove padding on 64bit
Date: Thu, 25 Mar 2010 11:27:36 +0000 [thread overview]
Message-ID: <1269516456.2054.8.camel@localhost> (raw)
Reorder structure to remove 8 bytes of padding on 64 bit builds.
This shrinks the size to 128 bytes so allowing allocation from a smaller
slab & needed one fewer cache lines.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----
patch against 2.6.34-rc2
compiled & booted on x86_64
regards
Richard
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 05a9f83..421db5e 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -422,6 +422,7 @@ int ring_buffer_print_page_header(struct trace_seq
*s)
*/
struct ring_buffer_per_cpu {
int cpu;
+ atomic_t record_disabled;
struct ring_buffer *buffer;
spinlock_t reader_lock; /* serialize readers */
arch_spinlock_t lock;
@@ -439,7 +440,6 @@ struct ring_buffer_per_cpu {
unsigned long read;
u64 write_stamp;
u64 read_stamp;
- atomic_t record_disabled;
};
struct ring_buffer {
next reply other threads:[~2010-03-25 11:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-25 11:27 Richard Kennedy [this message]
2010-03-25 13:38 ` [PATCH] trace: reorder struct ring_buffer_per_cpu to remove padding on 64bit Steven Rostedt
2010-03-25 13:44 ` Richard Kennedy
2010-07-23 12:10 ` [tip:perf/core] trace: Reorder " tip-bot for Richard Kennedy
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