On 09/21/26 at 07:46pm, Ridong Chen wrote:
> From: Ridong Chen <[email protected]>
>
> Now that the vmscan tracepoints live in mm/trace_vmscan.h, move
> struct scan_control there as well so the trace events can reference
> reclaim-internal state directly. The definition is wrapped in its own
> include guard because the trace header is re-read under
> TRACE_HEADER_MULTI_READ, while a C struct may only be defined once.
>
> No functional change.
>
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Ridong Chen <[email protected]>
> ---
> mm/trace_vmscan.h | 115 ++++++++++++++++++++++++++++++++++++++++++++++
> mm/vmscan.c | 108 -------------------------------------------
> 2 files changed, 115 insertions(+), 108 deletions(-)
>
> diff --git a/mm/trace_vmscan.h b/mm/trace_vmscan.h
> index c5d824fef554..c8ac5d4e4043 100644
> --- a/mm/trace_vmscan.h
> +++ b/mm/trace_vmscan.h
This looks not good, I would rather see it's added in mm/internal.h, or
a new mm/vmscan.h. Putting scan_control in mm/trace_vmscan.h is too weird.
> @@ -9,8 +9,123 @@
> #include <linux/tracepoint.h>
> #include <linux/mm.h>
> #include <linux/memcontrol.h>
> +#include <linux/swap.h>
> #include <trace/events/mmflags.h>
>
> +/* Guard the struct against define_trace.h's repeated inclusion. */
> +#ifndef _MM_VMSCAN_INTERNAL_H
> +#define _MM_VMSCAN_INTERNAL_H
> +
> +struct scan_control {
> + /* How many pages shrink_list() should reclaim */
> + unsigned long nr_to_reclaim;
> +
> + /*
> + * Nodemask of nodes allowed by the caller. If NULL, all nodes
> + * are scanned.
> + */
> + const nodemask_t *nodemask;
> +
> + /*
> + * The memory cgroup that hit its limit and as a result is the
> + * primary target of this reclaim invocation.
> + */
> + struct mem_cgroup *target_mem_cgroup;
> +
> + /*
> + * Scan pressure balancing between anon and file LRUs
> + */
> + unsigned long anon_cost;
> + unsigned long file_cost;
> +
> + /* Swappiness value for proactive reclaim. Always use sc_swappiness()!
> */
> + int *proactive_swappiness;
> +
> + /* Can active folios be deactivated as part of reclaim? */
> +#define DEACTIVATE_ANON 1
> +#define DEACTIVATE_FILE 2
> + unsigned int may_deactivate:2;
> + unsigned int force_deactivate:1;
> + unsigned int skipped_deactivate:1;
> +
> + /* zone_reclaim_mode, boost reclaim */
> + unsigned int may_writepage:1;
> +
> + /* zone_reclaim_mode */
> + unsigned int may_unmap:1;
> +
> + /* zone_reclaim_mode, boost reclaim, cgroup restrictions */
> + unsigned int may_swap:1;
> +
> + /* Not allow cache_trim_mode to be turned on as part of reclaim? */
> + unsigned int no_cache_trim_mode:1;
> +
> + /* Has cache_trim_mode failed at least once? */
> + unsigned int cache_trim_mode_failed:1;
> +
> + /* Proactive reclaim invoked by userspace */
> + unsigned int proactive:1;
> +
> + /*
> + * Cgroup memory below memory.low is protected as long as we
> + * don't threaten to OOM. If any cgroup is reclaimed at
> + * reduced force or passed over entirely due to its memory.low
> + * setting (memcg_low_skipped), and nothing is reclaimed as a
> + * result, then go back for one more cycle that reclaims the protected
> + * memory (memcg_low_reclaim) to avert OOM.
> + */
> + unsigned int memcg_low_reclaim:1;
> + unsigned int memcg_low_skipped:1;
> +
> + /* Shared cgroup tree walk failed, rescan the whole tree */
> + unsigned int memcg_full_walk:1;
> +
> + unsigned int hibernation_mode:1;
> +
> + /* One of the zones is ready for compaction */
> + unsigned int compaction_ready:1;
> +
> + /* There is easily reclaimable cold cache in the current node */
> + unsigned int cache_trim_mode:1;
> +
> + /* The file folios on the current node are dangerously low */
> + unsigned int file_is_tiny:1;
> +
> + /* Always discard instead of demoting to lower tier memory */
> + unsigned int no_demotion:1;
> +
> + /* Allocation order */
> + s8 order;
> +
> + /* Scan (total_size >> priority) pages at once */
> + s8 priority;
> +
> + /* The highest zone to isolate folios for reclaim from */
> + s8 reclaim_idx;
> +
> + /* This context's GFP mask */
> + gfp_t gfp_mask;
> +
> + /* Incremented by the number of inactive pages that were scanned */
> + unsigned long nr_scanned;
> +
> + /* Number of pages freed so far during a call to shrink_zones() */
> + unsigned long nr_reclaimed;
> +
> + struct {
> + unsigned int dirty;
> + unsigned int congested;
> + unsigned int writeback;
> + unsigned int immediate;
> + unsigned int taken;
> + } nr;
> +
> + /* for recording the reclaimed slab by now */
> + struct reclaim_state reclaim_state;
> +};
> +
> +#endif /* _MM_VMSCAN_INTERNAL_H */
> +
> #define RECLAIM_WB_ANON 0x0001u
> #define RECLAIM_WB_FILE 0x0002u
> #define RECLAIM_WB_MIXED 0x0010u
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 0eb7fa8e1d43..2fd9b42f89d8 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -73,114 +73,6 @@
> #define CREATE_TRACE_POINTS
> #include "trace_vmscan.h"
>
> -struct scan_control {
> - /* How many pages shrink_list() should reclaim */
> - unsigned long nr_to_reclaim;
> -
> - /*
> - * Nodemask of nodes allowed by the caller. If NULL, all nodes
> - * are scanned.
> - */
> - const nodemask_t *nodemask;
> -
> - /*
> - * The memory cgroup that hit its limit and as a result is the
> - * primary target of this reclaim invocation.
> - */
> - struct mem_cgroup *target_mem_cgroup;
> -
> - /*
> - * Scan pressure balancing between anon and file LRUs
> - */
> - unsigned long anon_cost;
> - unsigned long file_cost;
> -
> - /* Swappiness value for proactive reclaim. Always use sc_swappiness()!
> */
> - int *proactive_swappiness;
> -
> - /* Can active folios be deactivated as part of reclaim? */
> -#define DEACTIVATE_ANON 1
> -#define DEACTIVATE_FILE 2
> - unsigned int may_deactivate:2;
> - unsigned int force_deactivate:1;
> - unsigned int skipped_deactivate:1;
> -
> - /* zone_reclaim_mode, boost reclaim */
> - unsigned int may_writepage:1;
> -
> - /* zone_reclaim_mode */
> - unsigned int may_unmap:1;
> -
> - /* zone_reclaim_mode, boost reclaim, cgroup restrictions */
> - unsigned int may_swap:1;
> -
> - /* Not allow cache_trim_mode to be turned on as part of reclaim? */
> - unsigned int no_cache_trim_mode:1;
> -
> - /* Has cache_trim_mode failed at least once? */
> - unsigned int cache_trim_mode_failed:1;
> -
> - /* Proactive reclaim invoked by userspace */
> - unsigned int proactive:1;
> -
> - /*
> - * Cgroup memory below memory.low is protected as long as we
> - * don't threaten to OOM. If any cgroup is reclaimed at
> - * reduced force or passed over entirely due to its memory.low
> - * setting (memcg_low_skipped), and nothing is reclaimed as a
> - * result, then go back for one more cycle that reclaims the protected
> - * memory (memcg_low_reclaim) to avert OOM.
> - */
> - unsigned int memcg_low_reclaim:1;
> - unsigned int memcg_low_skipped:1;
> -
> - /* Shared cgroup tree walk failed, rescan the whole tree */
> - unsigned int memcg_full_walk:1;
> -
> - unsigned int hibernation_mode:1;
> -
> - /* One of the zones is ready for compaction */
> - unsigned int compaction_ready:1;
> -
> - /* There is easily reclaimable cold cache in the current node */
> - unsigned int cache_trim_mode:1;
> -
> - /* The file folios on the current node are dangerously low */
> - unsigned int file_is_tiny:1;
> -
> - /* Always discard instead of demoting to lower tier memory */
> - unsigned int no_demotion:1;
> -
> - /* Allocation order */
> - s8 order;
> -
> - /* Scan (total_size >> priority) pages at once */
> - s8 priority;
> -
> - /* The highest zone to isolate folios for reclaim from */
> - s8 reclaim_idx;
> -
> - /* This context's GFP mask */
> - gfp_t gfp_mask;
> -
> - /* Incremented by the number of inactive pages that were scanned */
> - unsigned long nr_scanned;
> -
> - /* Number of pages freed so far during a call to shrink_zones() */
> - unsigned long nr_reclaimed;
> -
> - struct {
> - unsigned int dirty;
> - unsigned int congested;
> - unsigned int writeback;
> - unsigned int immediate;
> - unsigned int taken;
> - } nr;
> -
> - /* for recording the reclaimed slab by now */
> - struct reclaim_state reclaim_state;
> -};
> -
> #ifdef ARCH_HAS_PREFETCHW
> static inline void prefetchw_prev_lru_folio(struct folio *folio,
> struct list_head *base)
> --
> 2.34.1
>
