diff mbox series

[RFC,v2,2/6] mm: mempolicy: Revise comment regarding mempolicy mode flags

Message ID 20231122141559.4228-3-laoar.shao@gmail.com (mailing list archive)
State Superseded
Headers show
Series mm, security, bpf: Fine-grained control over memory policy adjustments with lsm bpf | expand

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Commit Message

Yafang Shao Nov. 22, 2023, 2:15 p.m. UTC
MPOL_F_STATIC_NODES, MPOL_F_RELATIVE_NODES, and MPOL_F_NUMA_BALANCING are
mode flags applicable to both set_mempolicy(2) and mbind(2) system calls.
It's worth noting that MPOL_F_NUMA_BALANCING was initially introduced in
commit bda420b98505 ("numa balancing: migrate on fault among multiple bound
nodes") exclusively for set_mempolicy(2). However, it was later made a
shared flag for both set_mempolicy(2) and mbind(2) following
commit 6d2aec9e123b ("mm/mempolicy: do not allow illegal
MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()").

This revised version aims to clarify the details regarding the mode flags.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
---
 include/uapi/linux/mempolicy.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Huang, Ying Nov. 23, 2023, 6:30 a.m. UTC | #1
Yafang Shao <laoar.shao@gmail.com> writes:

> MPOL_F_STATIC_NODES, MPOL_F_RELATIVE_NODES, and MPOL_F_NUMA_BALANCING are
> mode flags applicable to both set_mempolicy(2) and mbind(2) system calls.
> It's worth noting that MPOL_F_NUMA_BALANCING was initially introduced in
> commit bda420b98505 ("numa balancing: migrate on fault among multiple bound
> nodes") exclusively for set_mempolicy(2). However, it was later made a
> shared flag for both set_mempolicy(2) and mbind(2) following
> commit 6d2aec9e123b ("mm/mempolicy: do not allow illegal
> MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()").
>
> This revised version aims to clarify the details regarding the mode flags.
>
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: "Huang, Ying" <ying.huang@intel.com>

Thanks for fixing this.

Reviewed-by: "Huang, Ying" <ying.huang@intel.com>

And, please revise the manpage for mbind() too.  As we have done for
set_mempolicy(),

https://lore.kernel.org/all/20210120061235.148637-3-ying.huang@intel.com/

--
Best Regards,
Huang, Ying

> ---
>  include/uapi/linux/mempolicy.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
> index a8963f7ef4c2..afed4a45f5b9 100644
> --- a/include/uapi/linux/mempolicy.h
> +++ b/include/uapi/linux/mempolicy.h
> @@ -26,7 +26,7 @@ enum {
>  	MPOL_MAX,	/* always last member of enum */
>  };
>  
> -/* Flags for set_mempolicy */
> +/* Flags for set_mempolicy() or mbind() */
>  #define MPOL_F_STATIC_NODES	(1 << 15)
>  #define MPOL_F_RELATIVE_NODES	(1 << 14)
>  #define MPOL_F_NUMA_BALANCING	(1 << 13) /* Optimize with NUMA balancing if possible */
Yafang Shao Nov. 23, 2023, 12:21 p.m. UTC | #2
On Thu, Nov 23, 2023 at 2:32 PM Huang, Ying <ying.huang@intel.com> wrote:
>
> Yafang Shao <laoar.shao@gmail.com> writes:
>
> > MPOL_F_STATIC_NODES, MPOL_F_RELATIVE_NODES, and MPOL_F_NUMA_BALANCING are
> > mode flags applicable to both set_mempolicy(2) and mbind(2) system calls.
> > It's worth noting that MPOL_F_NUMA_BALANCING was initially introduced in
> > commit bda420b98505 ("numa balancing: migrate on fault among multiple bound
> > nodes") exclusively for set_mempolicy(2). However, it was later made a
> > shared flag for both set_mempolicy(2) and mbind(2) following
> > commit 6d2aec9e123b ("mm/mempolicy: do not allow illegal
> > MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()").
> >
> > This revised version aims to clarify the details regarding the mode flags.
> >
> > Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> > Cc: Eric Dumazet <edumazet@google.com>
> > Cc: "Huang, Ying" <ying.huang@intel.com>
>
> Thanks for fixing this.
>
> Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
>
> And, please revise the manpage for mbind() too.  As we have done for
> set_mempolicy(),
>
> https://lore.kernel.org/all/20210120061235.148637-3-ying.huang@intel.com/

Thanks for your review. will do it.
diff mbox series

Patch

diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index a8963f7ef4c2..afed4a45f5b9 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -26,7 +26,7 @@  enum {
 	MPOL_MAX,	/* always last member of enum */
 };
 
-/* Flags for set_mempolicy */
+/* Flags for set_mempolicy() or mbind() */
 #define MPOL_F_STATIC_NODES	(1 << 15)
 #define MPOL_F_RELATIVE_NODES	(1 << 14)
 #define MPOL_F_NUMA_BALANCING	(1 << 13) /* Optimize with NUMA balancing if possible */