[RFC][PATCH 11/11] optimize c/r check in dup_fd()

From: Dave Hansen
Date: Thu Mar 05 2009 - 11:41:36 EST



__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@xxxxxxxxxxxxxxxxxx>
---

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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