Subject: [RFC][PATCH 11/11] optimize c/r check in dup_fd()
To: Ingo Molnar <mingo@elte.hu>
Cc: containers <containers@lists.linux-foundation.org>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "Serge E. Hallyn" <serue@us.ibm.com>,
       Oren Laadan <orenl@cs.columbia.edu>,
       Alexey Dobriyan <adobriyan@gmail.com>,
       Christoph Hellwig <hch@infradead.org>,
       Dave Hansen <dave@linux.vnet.ibm.com>
From: Dave Hansen <dave@linux.vnet.ibm.com>
Date: Thu, 05 Mar 2009 08:39:13 -0800
References: <20090305163857.0C18F3FD@kernel>
In-Reply-To: <20090305163857.0C18F3FD@kernel>
Message-Id: <20090305163913.E59C59BB@kernel>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1146
Lines: 37


__scan_files_for_cr() should compile down to nothing
if checkpoint/restart is disabled.

But, I think the spinlocks in fcheck_files() keep
the compiler from figuring this out.  So, instead
if putting in some #ifdefs, use our new cr_enabled()
helper.

I've verified that this puts .text size back to
where it was without the __scan_files_for_cr() call.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
---

 linux-2.6.git-dave/fs/file.c |    3 +++
 1 file changed, 3 insertions(+)

diff -puN fs/file.c~optimize-cr-checkk fs/file.c
--- linux-2.6.git/fs/file.c~optimize-cr-checkk	2009-03-05 08:37:05.000000000 -0800
+++ linux-2.6.git-dave/fs/file.c	2009-03-05 08:37:05.000000000 -0800
@@ -290,6 +290,9 @@ static void __scan_files_for_cr(struct f
 {
 	int i;
 
+	if (!cr_enabled())
+		return;
+
 	for (i = 0; i < files->fdtab.max_fds; i++) {
 		struct file *f = fcheck_files(files, i);
 		if (!f)
_
--
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