The swapaccount deprecation warning is throwing false positives. Since
we deprecated the knob and defaulted to enabling, the only reports
we've been getting are from folks that set swapaccount=1. While this
is a nice affirmation that always-enabling was the right choice, we
certainly don't want to warn when users request the supported mode.
Only warn when disabling is requested, and clarify the warning.
Fixes: b25806dcd3d5 ("mm: memcontrol: deprecate swapaccounting=0 mode")
Cc: [email protected]
Reported-by: "Jonas Schäfer" <[email protected]>
Reported-by: Narcis Garcia <[email protected]>
Suggested-by: Yosry Ahmed <[email protected]>
Signed-off-by: Johannes Weiner <[email protected]>
---
mm/memcontrol.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1ed40f9d3a27..107ec5d36819 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -7971,9 +7971,13 @@ bool mem_cgroup_swap_full(struct folio *folio)
static int __init setup_swap_account(char *s)
{
- pr_warn_once("The swapaccount= commandline option is deprecated. "
- "Please report your usecase to [email protected] if you "
- "depend on this functionality.\n");
+ bool res;
+
+ if (!kstrtobool(s, &res) && !res)
+ pr_warn_once("The swapaccount=0 commdandline option is deprecated "
+ "in favor of configuring swap control via cgroupfs. "
+ "Please report your usecase to [email protected] if you "
+ "depend on this functionality.\n");
return 1;
}
__setup("swapaccount=", setup_swap_account);
--
2.43.0
On Tue 13-02-24 03:16:34, Johannes Weiner wrote:
> The swapaccount deprecation warning is throwing false positives. Since
> we deprecated the knob and defaulted to enabling, the only reports
> we've been getting are from folks that set swapaccount=1. While this
> is a nice affirmation that always-enabling was the right choice, we
> certainly don't want to warn when users request the supported mode.
>
> Only warn when disabling is requested, and clarify the warning.
>
> Fixes: b25806dcd3d5 ("mm: memcontrol: deprecate swapaccounting=0 mode")
> Cc: [email protected]
> Reported-by: "Jonas Sch?fer" <[email protected]>
> Reported-by: Narcis Garcia <[email protected]>
> Suggested-by: Yosry Ahmed <[email protected]>
> Signed-off-by: Johannes Weiner <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Thanks!
> ---
> mm/memcontrol.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 1ed40f9d3a27..107ec5d36819 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -7971,9 +7971,13 @@ bool mem_cgroup_swap_full(struct folio *folio)
>
> static int __init setup_swap_account(char *s)
> {
> - pr_warn_once("The swapaccount= commandline option is deprecated. "
> - "Please report your usecase to [email protected] if you "
> - "depend on this functionality.\n");
> + bool res;
> +
> + if (!kstrtobool(s, &res) && !res)
> + pr_warn_once("The swapaccount=0 commdandline option is deprecated "
> + "in favor of configuring swap control via cgroupfs. "
> + "Please report your usecase to [email protected] if you "
> + "depend on this functionality.\n");
> return 1;
> }
> __setup("swapaccount=", setup_swap_account);
> --
> 2.43.0
--
Michal Hocko
SUSE Labs
On Tue, Feb 13, 2024 at 12:16 AM Johannes Weiner <[email protected]> wrote:
>
> The swapaccount deprecation warning is throwing false positives. Since
> we deprecated the knob and defaulted to enabling, the only reports
> we've been getting are from folks that set swapaccount=1. While this
> is a nice affirmation that always-enabling was the right choice, we
> certainly don't want to warn when users request the supported mode.
>
> Only warn when disabling is requested, and clarify the warning.
>
> Fixes: b25806dcd3d5 ("mm: memcontrol: deprecate swapaccounting=0 mode")
> Cc: [email protected]
> Reported-by: "Jonas Schäfer" <[email protected]>
> Reported-by: Narcis Garcia <[email protected]>
> Suggested-by: Yosry Ahmed <[email protected]>
> Signed-off-by: Johannes Weiner <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
On Tue, Feb 13, 2024 at 03:16:34AM -0500, Johannes Weiner <[email protected]> wrote:
> The swapaccount deprecation warning is throwing false positives. Since
> we deprecated the knob and defaulted to enabling, the only reports
> we've been getting are from folks that set swapaccount=1. While this
> is a nice affirmation that always-enabling was the right choice, we
> certainly don't want to warn when users request the supported mode.
But shouldn't such users be still warned about effectively unused option?
I think `return 0;` from the param handler should ensure that.
> + if (!kstrtobool(s, &res) && !res)
> + pr_warn_once("The swapaccount=0 commdandline option is deprecated "
commandline
Regards,
Michal