Re: [PATCH v5 2/6] mm/vmscan: move vmscan tracepoints to a local header

[Baoquan He <baoquan.he@linux.dev>]

On 10/31/26 at 05:00pm, Ridong Chen wrote:
> From: Ridong Chen <chenridong@xiaomi.com>
> 
> Move include/trace/events/vmscan.h to mm/trace_vmscan.h so that the
> tracepoints can be extended to reference vmscan-internal structures such
> as struct scan_control, which is not visible outside mm/.  This mirrors
> what several other subsystems already do with their trace headers (e.g.
> fs/fuse/fuse_trace.h, fs/gfs2/trace_gfs2.h, fs/lockd/trace.h).  As they
> do, set TRACE_INCLUDE_PATH to "." and add mm/ to the include path of
> vmscan.o, the only user that defines CREATE_TRACE_POINTS.
> 
> No functional change.
> 
> Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
> Reviewed-by: Barry Song <baohua@kernel.org>
> ---
>  MAINTAINERS                                        | 2 ++
>  mm/Makefile                                        | 1 +
>  mm/shrinker.c                                      | 2 +-
>  include/trace/events/vmscan.h => mm/trace_vmscan.h | 4 ++++
>  mm/vmscan.c                                        | 2 +-
>  5 files changed, 9 insertions(+), 2 deletions(-)
>  rename include/trace/events/vmscan.h => mm/trace_vmscan.h (99%)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index aaf2825ac945..2ad01107fa05 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17653,6 +17653,7 @@ F:	Documentation/admin-guide/mm/multigen_lru.rst
>  F:	Documentation/mm/multigen_lru.rst
>  F:	include/linux/mm_inline.h
>  F:	include/linux/mmzone.h
> +F:	mm/trace_vmscan.h
>  F:	mm/vmscan.c
>  F:	mm/workingset.c
>  
> @@ -17802,6 +17803,7 @@ R:	Shakeel Butt <shakeel.butt@linux.dev>
>  R:	Lorenzo Stoakes <ljs@kernel.org>
>  L:	linux-mm@kvack.org
>  S:	Maintained
> +F:	mm/trace_vmscan.h
>  F:	mm/vmscan.c
>  F:	mm/workingset.c
>  
> diff --git a/mm/Makefile b/mm/Makefile
> index 2a3ec53d62ee..277b97f7f8d7 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -32,6 +32,7 @@ KCOV_INSTRUMENT_vmstat.o := n
>  KCOV_INSTRUMENT_failslab.o := n
>  
>  CFLAGS_init-mm.o += -Wno-override-init
> +CFLAGS_vmscan.o += -I$(src)

One nit:

Does it really need the above line? It affects mm/shrinker.c too, did your
shrinker.o building fail?

Seems it's redundant because kbuild adds -I$(src) -I$(obj) for every object
in the directory since commit cdd750bfb1f7 ("kbuild: remove 'addtree' and
'flags' magic for header search paths"). Please correct me if I am
wrong.

Other than the nit, this patch looks good to me,

Reviewed-by: Baoquan He <baoquan.he@linux.dev>

Thanks.
>  
>  mmu-y			:= nommu.o
>  mmu-$(CONFIG_MMU)	:= highmem.o memory.o mincore.o \
> diff --git a/mm/shrinker.c b/mm/shrinker.c
> index 4fb424e721bc..4fbdade6d2f6 100644
> --- a/mm/shrinker.c
> +++ b/mm/shrinker.c
> @@ -3,7 +3,7 @@
>  #include <linux/rwsem.h>
>  #include <linux/shrinker.h>
>  #include <linux/rculist.h>
> -#include <trace/events/vmscan.h>
> +#include "trace_vmscan.h"
>  
>  #include "internal.h"
>  
> diff --git a/include/trace/events/vmscan.h b/mm/trace_vmscan.h
> similarity index 99%
> rename from include/trace/events/vmscan.h
> rename to mm/trace_vmscan.h
> index 8a872990b4be..ad90f0e9bf2e 100644
> --- a/include/trace/events/vmscan.h
> +++ b/mm/trace_vmscan.h
> @@ -648,4 +648,8 @@ TRACE_EVENT(mm_vmscan_kswapd_clear_hopeless,
>  #endif /* _TRACE_VMSCAN_H */
>  
>  /* This part must be outside protection */
> +#undef TRACE_INCLUDE_FILE
> +#undef TRACE_INCLUDE_PATH
> +#define TRACE_INCLUDE_PATH .
> +#define TRACE_INCLUDE_FILE trace_vmscan
>  #include <trace/define_trace.h>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 9959ca158ce8..79d2d614afd0 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -71,7 +71,7 @@
>  #include "swap.h"
>  
>  #define CREATE_TRACE_POINTS
> -#include <trace/events/vmscan.h>
> +#include "trace_vmscan.h"
>  
>  struct scan_control {
>  	/* How many pages shrink_list() should reclaim */
> -- 
> 2.43.0
>