From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754665Ab0CYL1j (ORCPT ); Thu, 25 Mar 2010 07:27:39 -0400 Received: from lon1-post-1.mail.demon.net ([195.173.77.148]:55927 "EHLO lon1-post-1.mail.demon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754558Ab0CYL1i (ORCPT ); Thu, 25 Mar 2010 07:27:38 -0400 Subject: [PATCH] trace: reorder struct ring_buffer_per_cpu to remove padding on 64bit From: Richard Kennedy To: Steven Rostedt , Frederic Weisbecker , Ingo Molnar Cc: lkml Content-Type: text/plain; charset="UTF-8" Date: Thu, 25 Mar 2010 11:27:36 +0000 Message-ID: <1269516456.2054.8.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 (2.28.3-1.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 ---- 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 {