2022-04-16 02:20:05

by Luis Chamberlain

Subject: [PATCH sysctl-next] mm: fix unused variable kernel warning when SYSCTL=n

When CONFIG_SYSCTL=n the variable dirty_bytes_min which is just used
as a minimum to a proc handler is not used. So just move this under
the ifdef for CONFIG_SYSCTL.

Fixes: aa779e510219 ("mm: move page-writeback sysctls to their own file")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
---

Andrew, I can this via sysctl-next if that's OK with you.

mm/page-writeback.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 438762173a59..4f51d0ac5043 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -89,9 +89,6 @@ static int vm_highmem_is_dirtyable;
*/
static int vm_dirty_ratio = 20;

-/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
-static const unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
-
/*
* vm_dirty_bytes starts at 0 (disabled) so that it is a function of
* vm_dirty_ratio * the amount of dirtyable memory
@@ -2077,6 +2074,10 @@ static int page_writeback_cpu_online(unsigned int cpu)
}

#ifdef CONFIG_SYSCTL
+
+/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
+static const unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
+
static struct ctl_table vm_page_writeback_sysctls[] = {
{
.procname = "dirty_background_ratio",
--
2.35.1

2022-04-19 11:36:09

by Andrew Morton

Subject: Re: [PATCH sysctl-next] mm: fix unused variable kernel warning when SYSCTL=n

On Fri, 15 Apr 2022 15:15:02 -0700 Luis Chamberlain <[email protected]> wrote:

> When CONFIG_SYSCTL=n the variable dirty_bytes_min which is just used
> as a minimum to a proc handler is not used. So just move this under
> the ifdef for CONFIG_SYSCTL.

Acked-by: Andrew Morton <[email protected]>