From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 25 Aug 2022 18:41:26 +0200
Subject: [PATCH 3/8] mm/vmstat: Use preempt_[dis|en]able_nested()

Replace the open coded CONFIG_PREEMPT_RT conditional
preempt_enable/disable() pairs with the new helper functions which hide
the underlying implementation details.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220825164131.402717-4-bigeasy@linutronix.de
---
 mm/vmstat.c |   36 ++++++++++++------------------------
 1 file changed, 12 insertions(+), 24 deletions(-)

@ mm/vmstat.c:358 @ void __mod_zone_page_state(struct zone *
 	 * CPU migrations and preemption potentially corrupts a counter so
 	 * disable preemption.
 	 */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+	preempt_disable_nested();
 
 	x = delta + __this_cpu_read(*p);
 
@ mm/vmstat.c:370 @ void __mod_zone_page_state(struct zone *
 	}
 	__this_cpu_write(*p, x);
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+	preempt_enable_nested();
 }
 EXPORT_SYMBOL(__mod_zone_page_state);
 
@ mm/vmstat.c:394 @ void __mod_node_page_state(struct pglist
 	}
 
 	/* See __mod_node_page_state */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+	preempt_disable_nested();
 
 	x = delta + __this_cpu_read(*p);
 
@ mm/vmstat.c:406 @ void __mod_node_page_state(struct pglist
 	}
 	__this_cpu_write(*p, x);
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+	preempt_enable_nested();
 }
 EXPORT_SYMBOL(__mod_node_page_state);
 
@ mm/vmstat.c:440 @ void __inc_zone_state(struct zone *zone,
 	s8 v, t;
 
 	/* See __mod_node_page_state */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+	preempt_disable_nested();
 
 	v = __this_cpu_inc_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
@ mm/vmstat.c:451 @ void __inc_zone_state(struct zone *zone,
 		__this_cpu_write(*p, -overstep);
 	}
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+	preempt_enable_nested();
 }
 
 void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
@ mm/vmstat.c:463 @ void __inc_node_state(struct pglist_data
 	VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
 
 	/* See __mod_node_page_state */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+	preempt_disable_nested();
 
 	v = __this_cpu_inc_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
@ mm/vmstat.c:474 @ void __inc_node_state(struct pglist_data
 		__this_cpu_write(*p, -overstep);
 	}
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+	preempt_enable_nested();
 }
 
 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
@ mm/vmstat.c:496 @ void __dec_zone_state(struct zone *zone,
 	s8 v, t;
 
 	/* See __mod_node_page_state */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+	preempt_disable_nested();
 
 	v = __this_cpu_dec_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
@ mm/vmstat.c:507 @ void __dec_zone_state(struct zone *zone,
 		__this_cpu_write(*p, overstep);
 	}
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+	preempt_enable_nested();
 }
 
 void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
@ mm/vmstat.c:519 @ void __dec_node_state(struct pglist_data
 	VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
 
 	/* See __mod_node_page_state */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+	preempt_disable_nested();
 
 	v = __this_cpu_dec_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
@ mm/vmstat.c:530 @ void __dec_node_state(struct pglist_data
 		__this_cpu_write(*p, overstep);
 	}
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+	preempt_enable_nested();
 }
 
 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)