[PATCH 1/6] sched/numa, mm: make numa migrate functions to take a folio

From: Kefeng Wang
Date: Mon Sep 18 2023 - 06:33:57 EST


The cpuid(or access time) is stored in the head page for THP, so it is
safely to make should_numa_migrate_memory() and numa_hint_fault_latency()
to take a folio. This is in preparation for large folio numa balancing.

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
include/linux/sched/numa_balancing.h | 4 ++--
kernel/sched/fair.c | 12 ++++++------
mm/mempolicy.c | 3 ++-
3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/include/linux/sched/numa_balancing.h b/include/linux/sched/numa_balancing.h
index 3988762efe15..a38528c28665 100644
--- a/include/linux/sched/numa_balancing.h
+++ b/include/linux/sched/numa_balancing.h
@@ -20,7 +20,7 @@ extern void task_numa_fault(int last_node, int node, int pages, int flags);
extern pid_t task_numa_group_id(struct task_struct *p);
extern void set_numabalancing_state(bool enabled);
extern void task_numa_free(struct task_struct *p, bool final);
-extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
+extern bool should_numa_migrate_memory(struct task_struct *p, struct folio *folio,
int src_nid, int dst_cpu);
#else
static inline void task_numa_fault(int last_node, int node, int pages,
@@ -38,7 +38,7 @@ static inline void task_numa_free(struct task_struct *p, bool final)
{
}
static inline bool should_numa_migrate_memory(struct task_struct *p,
- struct page *page, int src_nid, int dst_cpu)
+ struct folio *folio, int src_nid, int dst_cpu)
{
return true;
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index cb225921bbca..683cc1e417d7 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1722,12 +1722,12 @@ static bool pgdat_free_space_enough(struct pglist_data *pgdat)
* The smaller the hint page fault latency, the higher the possibility
* for the page to be hot.
*/
-static int numa_hint_fault_latency(struct page *page)
+static int numa_hint_fault_latency(struct folio *folio)
{
int last_time, time;

time = jiffies_to_msecs(jiffies);
- last_time = xchg_page_access_time(page, time);
+ last_time = xchg_page_access_time(&folio->page, time);

return (time - last_time) & PAGE_ACCESS_TIME_MASK;
}
@@ -1784,7 +1784,7 @@ static void numa_promotion_adjust_threshold(struct pglist_data *pgdat,
}
}

-bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
+bool should_numa_migrate_memory(struct task_struct *p, struct folio *folio,
int src_nid, int dst_cpu)
{
struct numa_group *ng = deref_curr_numa_group(p);
@@ -1814,16 +1814,16 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
numa_promotion_adjust_threshold(pgdat, rate_limit, def_th);

th = pgdat->nbp_threshold ? : def_th;
- latency = numa_hint_fault_latency(page);
+ latency = numa_hint_fault_latency(folio);
if (latency >= th)
return false;

return !numa_promotion_rate_limit(pgdat, rate_limit,
- thp_nr_pages(page));
+ folio_nr_pages(folio));
}

this_cpupid = cpu_pid_to_cpupid(dst_cpu, current->pid);
- last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
+ last_cpupid = page_cpupid_xchg_last(&folio->page, this_cpupid);

if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) &&
!node_is_toptier(src_nid) && !cpupid_valid(last_cpupid))
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 42b5567e3773..39584dc25c84 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2642,7 +2642,8 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
if (pol->flags & MPOL_F_MORON) {
polnid = thisnid;

- if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
+ if (!should_numa_migrate_memory(current, page_folio(page),
+ curnid, thiscpu))
goto out;
}

--
2.27.0