From 9121c2ddd177a165dc36f79d6b197351c6ebd52b Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 12 May 2025 11:27:24 +0200 Subject: [PATCH] ipv4/route: Use this_cpu_inc() for stats on PREEMPT_RT [ Upstream commit 1c0829788a6e6e165846b9bedd0b908ef16260b6 ] The statistics are incremented with raw_cpu_inc() assuming it always happens with bottom half disabled. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this is no longer true. Use this_cpu_inc() on PREEMPT_RT for the increment to not worry about preemption. Cc: David Ahern Signed-off-by: Sebastian Andrzej Siewior Link: https://patch.msgid.link/20250512092736.229935-4-bigeasy@linutronix.de Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv4/route.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 97dc30a03dbf..8ee1ad2d8c13 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -192,7 +192,11 @@ const __u8 ip_tos2prio[16] = { EXPORT_SYMBOL(ip_tos2prio); static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); +#ifndef CONFIG_PREEMPT_RT #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) +#else +#define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field) +#endif #ifdef CONFIG_PROC_FS static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)