[PATCH v4 7/9] mm/vmscan: pass scan_control to mm_vmscan_balance_pgdat_end
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From: Ridong Chen <ridong.chen@linux.dev>
Date: 2026-10-19 04:23:58
Also in:
bpf, cgroups, linux-mm, lkml
Subsystem:
memory management, memory management - mglru (multi-gen lru), memory management - reclaim, the rest · Maintainers:
Andrew Morton, Johannes Weiner, Linus Torvalds
From: Ridong Chen <redacted> balance_pgdat() passes sc.order and sc.nr_reclaimed to mm_vmscan_balance_pgdat_end as bare arguments. Pass the enclosing struct scan_control instead and read the fields out in TP_fast_assign, consistent with the other reclaim tracepoints. highest_zoneidx stays a separate argument: it is a balance_pgdat() parameter, and sc.reclaim_idx may differ from it by the time the end event fires. No functional change. The tracefs event format (TP_STRUCT__entry and TP_printk) is unchanged, so tracefs-based consumers are unaffected. BPF programs attached via raw_tp/tp_btf see the new TP_PROTO and need to be adjusted; tracepoints are not a stable ABI (see Documentation/bpf/bpf_design_QA.rst). Assisted-by: LLM Signed-off-by: Ridong Chen <redacted> --- mm/trace_vmscan.h | 9 ++++----- mm/vmscan.c | 3 +-- 2 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/mm/trace_vmscan.h b/mm/trace_vmscan.h
index 54168ad45f6e..b2ad83e5f25e 100644
--- a/mm/trace_vmscan.h
+++ b/mm/trace_vmscan.h@@ -124,10 +124,9 @@ TRACE_EVENT(mm_vmscan_balance_pgdat_begin, TRACE_EVENT(mm_vmscan_balance_pgdat_end, - TP_PROTO(int nid, int order, int highest_zoneidx, - unsigned long nr_reclaimed), + TP_PROTO(int nid, struct scan_control *sc, int highest_zoneidx), - TP_ARGS(nid, order, highest_zoneidx, nr_reclaimed), + TP_ARGS(nid, sc, highest_zoneidx), TP_STRUCT__entry( __field(int, nid)
@@ -138,9 +137,9 @@ TRACE_EVENT(mm_vmscan_balance_pgdat_end, TP_fast_assign( __entry->nid = nid; - __entry->order = order; + __entry->order = sc->order; __entry->highest_zoneidx = highest_zoneidx; - __entry->nr_reclaimed = nr_reclaimed; + __entry->nr_reclaimed = sc->nr_reclaimed; ), TP_printk("nid=%d order=%d highest_zoneidx=%-8s nr_reclaimed=%lu",
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4bb00371a67f..5d699decaa28 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c@@ -7402,8 +7402,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int highest_zoneidx) psi_memstall_leave(&pflags); set_task_reclaim_state(current, NULL); - trace_mm_vmscan_balance_pgdat_end(pgdat->node_id, sc.order, - highest_zoneidx, sc.nr_reclaimed); + trace_mm_vmscan_balance_pgdat_end(pgdat->node_id, &sc, highest_zoneidx); /* * Return the order kswapd stopped reclaiming at as
--
2.34.1