Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP

Andrew Morton
2016-05-16T22:36:58Z

On Mon, 16 May 2016 16:23:33 +0200 Michal Hocko <mhocko@kernel.org> wrote:

> Andrew, I think that the following is more straightforward fix and
> should be folded in to the patch which has introduced vmstat_refresh.
> ---
> >From b8dd18fb7df040e1bfe61aadde1d903589de15e4 Mon Sep 17 00:00:00 2001
> From: Michal Hocko <mhocko@suse.com>
> Date: Mon, 16 May 2016 16:19:53 +0200
> Subject: [PATCH] mmotm: mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
>
> Arnd has reported:
> In randconfig builds with sysfs, procfs and numa all disabled,
> but SMP enabled, we now get a link error in the newly introduced
> vmstat_refresh function:
>
> mm/built-in.o: In function `vmstat_refresh':
> :(.text+0x15c78): undefined reference to `vmstat_text'
>
> vmstat_refresh is proc_fs specific so there is no reason to define it
> when !CONFIG_PROC_FS.

I already had this:

From: Christoph Lameter <cl@linux.com>
Subject: Do not build vmstat_refresh if there is no procfs support

It makes no sense to build functionality into the kernel that
cannot be used and causes build issues.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1605111011260.9351@east.gentwo.org
Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

mm/vmstat.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff -puN mm/vmstat.c~mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix mm/vmstat.c
--- a/mm/vmstat.c~mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
+++ a/mm/vmstat.c
@@ -1371,7 +1371,6 @@ static const struct file_operations proc
.llseek = seq_lseek,
.release = seq_release,
};
-#endif /* CONFIG_PROC_FS */

#ifdef CONFIG_SMP
static struct workqueue_struct *vmstat_wq;
@@ -1436,7 +1435,10 @@ int vmstat_refresh(struct ctl_table *tab
*lenp = 0;
return 0;
}
+#endif /* CONFIG_SMP */
+#endif /* CONFIG_PROC_FS */

+#ifdef CONFIG_SMP
static void vmstat_update(struct work_struct *w)
{
if (refresh_cpu_vm_stats(true)) {
_