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

Michal Hocko
2016-05-16T07:37:19Z

On Wed 11-05-16 16:54:55, Arnd Bergmann wrote:
> 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'
>
> This modifes the already elaborate #ifdef to also cover that
> configuration.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: mmotm ("mm: /proc/sys/vm/stat_refresh to force vmstat update")

I agree with Christoph that vmstat_refresh is PROC_FS only so we should
fix it there. It is not like this would be generally reusable helper...
Why don't we just do:
---
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 57a24e919907..c759b526287b 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1370,6 +1370,7 @@ static void refresh_vm_stats(struct work_struct *work)
refresh_cpu_vm_stats(true);
}

+#ifdef CONFIG_PROC_FS
int vmstat_refresh(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
@@ -1422,6 +1423,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
*lenp = 0;
return 0;
}
+#endif

static void vmstat_update(struct work_struct *w)
{
--
Michal Hocko
SUSE Labs