diff mbox series

[v3,3/3] Documentation/cgroup-v2: clarify that zswap.writeback is ignored if zswap is disabled

Message ID 20240823162506.12117-3-me@yhndnzj.com (mailing list archive)
State New
Headers show
Series [v3,1/3] mm/memcontrol: respect zswap.writeback setting from parent cg too | expand

Commit Message

Mike Yuan Aug. 23, 2024, 4:27 p.m. UTC
As discussed in [1], zswap-related settings natually
lose their effect when zswap is disabled, specifically
zswap.writeback here. Be explicit about this behavior.

[1] https://lore.kernel.org/linux-kernel/CAKEwX=Mhbwhh-=xxCU-RjMXS_n=RpV3Gtznb2m_3JgL+jzz++g@mail.gmail.com/

Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>

Signed-off-by: Mike Yuan <me@yhndnzj.com>
---
 Documentation/admin-guide/cgroup-v2.rst | 2 ++
 1 file changed, 2 insertions(+)

Comments

Mike Yuan Sept. 2, 2024, 2:13 p.m. UTC | #1
> As discussed in [1], zswap-related settings natually
> lose their effect when zswap is disabled, specifically
> zswap.writeback here. Be explicit about this behavior.
> 
> [1]
> https://lore.kernel.org/linux-kernel/CAKEwX=Mhbwhh-=xxCU-RjMXS_n=RpV3Gtznb2m_3JgL+jzz++g@mail.gmail.com/
> 
> Cc: Nhat Pham <nphamcs@gmail.com>
> Cc: Yosry Ahmed <yosryahmed@google.com>
> 
> Signed-off-by: Mike Yuan <me@yhndnzj.com>
> ---
>  Documentation/admin-guide/cgroup-v2.rst | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/admin-guide/cgroup-v2.rst
> b/Documentation/admin-guide/cgroup-v2.rst
> index 95c18bc17083..a1723e402596 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -1731,6 +1731,8 @@ The following nested keys are defined.
>  
>  	Note that this is subtly different from setting
> memory.swap.max to
>  	0, as it still allows for pages to be written to the zswap
> pool.
> +	This setting has no effect if zswap is disabled, and
> swapping
> +	would be allowed unless memory.swap.max is set to 0.
>  
>    memory.pressure
>  	A read-only nested-keyed file.

Hmm, Andrew, it seems that the commit messages of this and the previous
patch are somehow reversed/mismatched? [1][2] Could you please confirm
and fix it?

[1]:
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/commit/?h=mm-unstable&id=eef275964326760bb55803b167854981cab97e55
[2]:
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/commit/?h=mm-unstable&id=42c3628a37400c2bc4199b9f8423be701646d4e0
Andrew Morton Sept. 2, 2024, 9:02 p.m. UTC | #2
On Mon, 02 Sep 2024 14:13:43 +0000 Mike Yuan <me@yhndnzj.com> wrote:

> > +	This setting has no effect if zswap is disabled, and
> > swapping
> > +	would be allowed unless memory.swap.max is set to 0.
> >  
> >    memory.pressure
> >  	A read-only nested-keyed file.
> 
> Hmm, Andrew, it seems that the commit messages of this and the previous
> patch are somehow reversed/mismatched? [1][2] Could you please confirm
> and fix it?

Yup thanks, a side-effect of turning a three-patch series into a
one-patch hotfix and a two-patch series.
diff mbox series

Patch

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 95c18bc17083..a1723e402596 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1731,6 +1731,8 @@  The following nested keys are defined.
 
 	Note that this is subtly different from setting memory.swap.max to
 	0, as it still allows for pages to be written to the zswap pool.
+	This setting has no effect if zswap is disabled, and swapping
+	would be allowed unless memory.swap.max is set to 0.
 
   memory.pressure
 	A read-only nested-keyed file.