[PATCH v3 04/22] perf/events: replace READ_ONCE() with standard page table accessors

Samuel Holland samuel.holland at sifive.com
Wed Nov 12 17:45:17 PST 2025


From: Anshuman Khandual <anshuman.khandual at arm.com>

Replace READ_ONCE() with standard page table accessors i.e pxdp_get() which
anyways default into READ_ONCE() in cases where platform does not override.

Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Ingo Molnar <mingo at redhat.com>
Cc: Arnaldo Carvalho de Melo <acme at kernel.org>
Cc: Namhyung Kim <namhyung at kernel.org>
Cc: linux-perf-users at vger.kernel.org
Cc: linux-kernel at vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
Link: https://lore.kernel.org/r/20251006042622.1743675-1-anshuman.khandual@arm.com/
Signed-off-by: Samuel Holland <samuel.holland at sifive.com>
---

Changes in v3:
 - Replace my patch with Anshuman Khandual's patch from LKML

Changes in v2:
 - New patch for v2

 kernel/events/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1fd347da9026..fa4f9165bd94 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8122,7 +8122,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
 	pte_t *ptep, pte;
 
 	pgdp = pgd_offset(mm, addr);
-	pgd = READ_ONCE(*pgdp);
+	pgd = pgdp_get(pgdp);
 	if (pgd_none(pgd))
 		return 0;
 
@@ -8130,7 +8130,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
 		return pgd_leaf_size(pgd);
 
 	p4dp = p4d_offset_lockless(pgdp, pgd, addr);
-	p4d = READ_ONCE(*p4dp);
+	p4d = p4dp_get(p4dp);
 	if (!p4d_present(p4d))
 		return 0;
 
@@ -8138,7 +8138,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
 		return p4d_leaf_size(p4d);
 
 	pudp = pud_offset_lockless(p4dp, p4d, addr);
-	pud = READ_ONCE(*pudp);
+	pud = pudp_get(pudp);
 	if (!pud_present(pud))
 		return 0;
 
-- 
2.47.2




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