On 2024/7/24 21:01, Zi Yan wrote:
If memory tiering mode is on and a folio is not in the top tier memory,
folio's cpupid field is repurposed to store page access time. Instead of
an open coded check, use a function to encapsulate the check.
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
include/linux/mm.h | 6 ++++++
kernel/sched/fair.c | 3 +--
mm/huge_memory.c | 6 ++----
mm/memory-tiers.c | 19 +++++++++++++++++++
mm/memory.c | 3 +--
mm/mprotect.c | 3 +--
6 files changed, 30 insertions(+), 10 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 17753a463e01..2c6ccf088c7b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1717,6 +1717,8 @@ static inline void vma_set_access_pid_bit(struct vm_area_struct *vma)
__set_bit(pid_bit, &vma->numab_state->pids_active[1]);
}
}
+
+bool folio_use_access_time(struct folio *folio);
#else /* !CONFIG_NUMA_BALANCING */
static inline int folio_xchg_last_cpupid(struct folio *folio, int cpupid)
{
@@ -1770,6 +1772,10 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
static inline void vma_set_access_pid_bit(struct vm_area_struct *vma)
{
}
+static inline bool folio_use_access_time(struct folio *folio)
+{
+ return false;
+}
#endif /* CONFIG_NUMA_BALANCING */
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9057584ec06d..416e29b56cc4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1840,8 +1840,7 @@ bool should_numa_migrate_memory(struct task_struct *p, struct folio *folio,
* The pages in slow memory node should be migrated according
* to hot/cold instead of private/shared.
*/
- if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING &&
- !node_is_toptier(src_nid)) {
+ if (folio_use_access_time(folio)) {
struct pglist_data *pgdat;
unsigned long rate_limit;
unsigned int latency, th, def_th;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 15234b2e252e..5c0a6a4e3a6e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1707,8 +1707,7 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf)
* For memory tiering mode, cpupid of slow memory page is used
* to record page access time. So use default value.
*/
- if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) ||
- node_is_toptier(nid))
+ if (!folio_use_access_time(folio))
last_cpupid = folio_last_cpupid(folio);
target_nid = numa_migrate_prep(folio, vmf, haddr, nid, &flags);
if (target_nid == NUMA_NO_NODE)
@@ -2061,8 +2060,7 @@ int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
toptier)
goto unlock;
- if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING &&
- !toptier)
+ if (folio_use_access_time(folio))
folio_xchg_access_time(folio,
jiffies_to_msecs(jiffies));
}
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 4775b3a3dabe..2a642ea86cb2 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -6,6 +6,7 @@
#include <linux/memory.h>
#include <linux/memory-tiers.h>
#include <linux/notifier.h>
+#include <linux/sched/sysctl.h>
#include "internal.h"
@@ -50,6 +51,24 @@ static const struct bus_type memory_tier_subsys = {
.dev_name = "memory_tier",
};
+#ifdef CONFIG_NUMA_BALANCING
+/**
+ * folio_use_access_time - check if a folio reuses cpupid for page access time
+ * @folio: folio to check
+ *
+ * folio's _last_cpupid field is repurposed by memory tiering. In memory
+ * tiering mode, cpupid of slow memory folio (not toptier memory) is used to
+ * record page access time.
+ *
+ * Return: the folio _last_cpupid is used to record page access time
+ */
+bool folio_use_access_time(struct folio *folio)
+{
+ return (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) &&
+ !node_is_toptier(folio_nid(folio));
+}
+#endif
+
#ifdef CONFIG_MIGRATION
static int top_tier_adistance;
/*
diff --git a/mm/memory.c b/mm/memory.c
index 802d0d8a40f9..833d2cad6eb2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5337,8 +5337,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
* For memory tiering mode, cpupid of slow memory page is used
* to record page access time. So use default value.
*/
- if ((sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) &&
- !node_is_toptier(nid))
+ if (folio_use_access_time(folio))
last_cpupid = (-1 & LAST_CPUPID_MASK);
else
last_cpupid = folio_last_cpupid(folio);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 222ab434da54..37cf8d249405 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -161,8 +161,7 @@ static long change_pte_range(struct mmu_gather *tlb,
if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) &&
toptier)
continue;
- if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING &&
- !toptier)
+ if (folio_use_access_time(folio))
folio_xchg_access_time(folio,
jiffies_to_msecs(jiffies));
}
