+ vmstat-switch-per-cpu-vmstat-counters-to-32-bits.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

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The patch titled
     Subject: vmstat: switch per-cpu vmstat counters to 32-bits
has been added to the -mm mm-unstable branch.  Its filename is
     vmstat-switch-per-cpu-vmstat-counters-to-32-bits.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/vmstat-switch-per-cpu-vmstat-counters-to-32-bits.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: vmstat: switch per-cpu vmstat counters to 32-bits
Date: Mon, 13 Mar 2023 13:25:15 -0300

Some architectures only provide xchg/cmpxchg in 32/64-bit quantities.

Since the next patch is about to use xchg on per-CPU vmstat counters,
switch them to s32.

Link: https://lkml.kernel.org/r/20230313162634.458451052@redhat.com
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/include/linux/mmzone.h~vmstat-switch-per-cpu-vmstat-counters-to-32-bits
+++ a/include/linux/mmzone.h
@@ -689,8 +689,8 @@ struct per_cpu_pages {
 
 struct per_cpu_zonestat {
 #ifdef CONFIG_SMP
-	s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
-	s8 stat_threshold;
+	s32 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
+	s32 stat_threshold;
 #endif
 #ifdef CONFIG_NUMA
 	/*
@@ -703,8 +703,8 @@ struct per_cpu_zonestat {
 };
 
 struct per_cpu_nodestat {
-	s8 stat_threshold;
-	s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
+	s32 stat_threshold;
+	s32 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
 };
 
 #endif /* !__GENERATING_BOUNDS.H */
--- a/mm/vmstat.c~vmstat-switch-per-cpu-vmstat-counters-to-32-bits
+++ a/mm/vmstat.c
@@ -351,7 +351,7 @@ static inline void mod_zone_state(struct
 				  long delta, int overstep_mode)
 {
 	struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
-	s8 __percpu *p = pcp->vm_stat_diff + item;
+	s32 __percpu *p = pcp->vm_stat_diff + item;
 	long o, n, t, z;
 
 	do {
@@ -428,7 +428,7 @@ static inline void mod_node_state(struct
 				  int delta, int overstep_mode)
 {
 	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
-	s8 __percpu *p = pcp->vm_node_stat_diff + item;
+	s32 __percpu *p = pcp->vm_node_stat_diff + item;
 	long o, n, t, z;
 
 	if (vmstat_item_in_bytes(item)) {
@@ -525,7 +525,7 @@ void __mod_zone_page_state(struct zone *
 			   long delta)
 {
 	struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
-	s8 __percpu *p = pcp->vm_stat_diff + item;
+	s32 __percpu *p = pcp->vm_stat_diff + item;
 	long x;
 	long t;
 
@@ -556,7 +556,7 @@ void __mod_node_page_state(struct pglist
 				long delta)
 {
 	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
-	s8 __percpu *p = pcp->vm_node_stat_diff + item;
+	s32 __percpu *p = pcp->vm_node_stat_diff + item;
 	long x;
 	long t;
 
@@ -614,8 +614,8 @@ EXPORT_SYMBOL(__mod_node_page_state);
 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 {
 	struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
-	s8 __percpu *p = pcp->vm_stat_diff + item;
-	s8 v, t;
+	s32 __percpu *p = pcp->vm_stat_diff + item;
+	s32 v, t;
 
 	/* See __mod_node_page_state */
 	preempt_disable_nested();
@@ -623,7 +623,7 @@ void __inc_zone_state(struct zone *zone,
 	v = __this_cpu_inc_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
 	if (unlikely(v > t)) {
-		s8 overstep = t >> 1;
+		s32 overstep = t >> 1;
 
 		zone_page_state_add(v + overstep, zone, item);
 		__this_cpu_write(*p, -overstep);
@@ -635,8 +635,8 @@ void __inc_zone_state(struct zone *zone,
 void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
 {
 	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
-	s8 __percpu *p = pcp->vm_node_stat_diff + item;
-	s8 v, t;
+	s32 __percpu *p = pcp->vm_node_stat_diff + item;
+	s32 v, t;
 
 	VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
 
@@ -646,7 +646,7 @@ void __inc_node_state(struct pglist_data
 	v = __this_cpu_inc_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
 	if (unlikely(v > t)) {
-		s8 overstep = t >> 1;
+		s32 overstep = t >> 1;
 
 		node_page_state_add(v + overstep, pgdat, item);
 		__this_cpu_write(*p, -overstep);
@@ -670,8 +670,8 @@ EXPORT_SYMBOL(__inc_node_page_state);
 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 {
 	struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
-	s8 __percpu *p = pcp->vm_stat_diff + item;
-	s8 v, t;
+	s32 __percpu *p = pcp->vm_stat_diff + item;
+	s32 v, t;
 
 	/* See __mod_node_page_state */
 	preempt_disable_nested();
@@ -679,7 +679,7 @@ void __dec_zone_state(struct zone *zone,
 	v = __this_cpu_dec_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
 	if (unlikely(v < - t)) {
-		s8 overstep = t >> 1;
+		s32 overstep = t >> 1;
 
 		zone_page_state_add(v - overstep, zone, item);
 		__this_cpu_write(*p, overstep);
@@ -691,8 +691,8 @@ void __dec_zone_state(struct zone *zone,
 void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
 {
 	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
-	s8 __percpu *p = pcp->vm_node_stat_diff + item;
-	s8 v, t;
+	s32 __percpu *p = pcp->vm_node_stat_diff + item;
+	s32 v, t;
 
 	VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
 
@@ -702,7 +702,7 @@ void __dec_node_state(struct pglist_data
 	v = __this_cpu_dec_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
 	if (unlikely(v < - t)) {
-		s8 overstep = t >> 1;
+		s32 overstep = t >> 1;
 
 		node_page_state_add(v - overstep, pgdat, item);
 		__this_cpu_write(*p, overstep);
_

Patches currently in -mm which might be from mtosatti@redhat.com are

this_cpu_cmpxchg-arm64-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch
this_cpu_cmpxchg-loongarch-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch
this_cpu_cmpxchg-s390-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch
this_cpu_cmpxchg-x86-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch
add-this_cpu_cmpxchg_local-and-asm-generic-definitions.patch
convert-this_cpu_cmpxchg-users-to-this_cpu_cmpxchg_local.patch
mm-vmstat-switch-counter-modification-to-cmpxchg.patch
vmstat-switch-per-cpu-vmstat-counters-to-32-bits.patch
mm-vmstat-use-xchg-in-cpu_vm_stats_fold.patch
mm-vmstat-switch-vmstat-shepherd-to-flush-per-cpu-counters-remotely.patch
mm-vmstat-refresh-stats-remotely-instead-of-via-work-item.patch
vmstat-add-pcp-remote-node-draining-via-cpu_vm_stats_fold.patch