From 89b4cd4b9ebf15b01f70b85105ea5f5c6b2a3788 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 11 Jun 2018 12:29:16 -0700 Subject: [PATCH] rcu: Print stall-warning NMI dyntick state in hexadecimal The ->dynticks_nmi_nesting field records the nesting depth of both interrupt and NMI handlers. Because the kernel can enter interrupts and never leave them (and vice versa) and because NMIs can interrupt manipulation of the ->dynticks_nmi_nesting field, the values in this field must be both chosen and maniupated very carefully. As a result, although the value is zero when the corresponding CPU is executing neither an interrupt nor an NMI handler, it is 4,611,686,018,427,387,906 on 64-bit systems when there is a single level of interrupt/NMI handling in progress. This number is difficult to remember and interpret, so this commit switches the output to hexadecimal, resulting in the much nicer 0x4000000000000002. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_plugin.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 2cc9bf0d363a..c1b17f5b9361 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1801,7 +1801,7 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) } print_cpu_stall_fast_no_hz(fast_no_hz, cpu); delta = rcu_seq_ctr(rdp->mynode->gp_seq - rdp->rcu_iw_gp_seq); - pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%ld softirq=%u/%u fqs=%ld %s\n", + pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%#lx softirq=%u/%u fqs=%ld %s\n", cpu, "O."[!!cpu_online(cpu)], "o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)],