rcu: Print negatives for stall-warning counter wraparound

The print_other_cpu_stall() and print_cpu_stall() functions print
grace-period numbers using an unsigned format, which means that the number
one less than zero is a very large number.  This commit therefore causes
these numbers to be printed with a signed format in order to improve
readability of the RCU CPU stall-warning output.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 2c53ac924cab..b33c29a99df3 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -932,9 +932,9 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
         print_cpu_stall_info_end();
         for_each_possible_cpu(cpu)
                 totqlen += per_cpu_ptr(rsp->rda, cpu)->qlen;
-        pr_cont("(detected by %d, t=%ld jiffies, g=%lu, c=%lu, q=%lu)\n",
+        pr_cont("(detected by %d, t=%ld jiffies, g=%ld, c=%ld, q=%lu)\n",
                smp_processor_id(), (long)(jiffies - rsp->gp_start),
-               rsp->gpnum, rsp->completed, totqlen);
+               (long)rsp->gpnum, (long)rsp->completed, totqlen);
         if (ndetected == 0)
                 pr_err("INFO: Stall ended before state dump start\n");
         else if (!trigger_all_cpu_backtrace())
@@ -971,8 +971,9 @@ static void print_cpu_stall(struct rcu_state *rsp)
         print_cpu_stall_info_end();
         for_each_possible_cpu(cpu)
                 totqlen += per_cpu_ptr(rsp->rda, cpu)->qlen;
-        pr_cont(" (t=%lu jiffies g=%lu c=%lu q=%lu)\n",
-                jiffies - rsp->gp_start, rsp->gpnum, rsp->completed, totqlen);
+        pr_cont(" (t=%lu jiffies g=%ld c=%ld q=%lu)\n",
+                jiffies - rsp->gp_start,
+                (long)rsp->gpnum, (long)rsp->completed, totqlen);
         if (!trigger_all_cpu_backtrace())
                 dump_stack();