watchdog/hardlockup: style changes to watchdog_hardlockup_check() / is_hardlockup()

These are tiny style changes:
- Add a blank line before a "return".
- Renames two globals to use the "watchdog_hardlockup" prefix.
- Store processor id in "unsigned int" rather than "int".
- Minor comment rewording.
- Use "else" rather than extra returns since it seemed more symmetric.

Link: https://lkml.kernel.org/r/20230519101840.v5.9.I818492c326b632560b09f20d2608455ecf9d3650@changeid
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 12ce37d..169e5df 100644 (file)
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -89,8 +89,8 @@ __setup("nmi_watchdog=", hardlockup_panic_setup);
 
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
-static DEFINE_PER_CPU(bool, hard_watchdog_warn);
-static unsigned long hardlockup_allcpu_dumped;
+static DEFINE_PER_CPU(bool, watchdog_hardlockup_warned);
+static unsigned long watchdog_hardlockup_all_cpu_dumped;
 
 static bool is_hardlockup(void)
 {
@@ -100,6 +100,7 @@ static bool is_hardlockup(void)
                return true;
 
        __this_cpu_write(hrtimer_interrupts_saved, hrint);
+
        return false;
 }
 
@@ -110,21 +111,20 @@ static void watchdog_hardlockup_kick(void)
 
 void watchdog_hardlockup_check(struct pt_regs *regs)
 {
-       /* check for a hardlockup
-        * This is done by making sure our timer interrupt
-        * is incrementing.  The timer interrupt should have
-        * fired multiple times before we overflow'd.  If it hasn't
+       /*
+        * Check for a hardlockup by making sure the CPU's timer
+        * interrupt is incrementing. The timer interrupt should have
+        * fired multiple times before we overflow'd. If it hasn't
         * then this is a good indication the cpu is stuck
         */
        if (is_hardlockup()) {
-               int this_cpu = smp_processor_id();
+               unsigned int this_cpu = smp_processor_id();
 
-               /* only print hardlockups once */
-               if (__this_cpu_read(hard_watchdog_warn) == true)
+               /* Only print hardlockups once. */
+               if (__this_cpu_read(watchdog_hardlockup_warned))
                        return;
 
-               pr_emerg("Watchdog detected hard LOCKUP on cpu %d\n",
-                        this_cpu);
+               pr_emerg("Watchdog detected hard LOCKUP on cpu %d\n", this_cpu);
                print_modules();
                print_irqtrace_events(current);
                if (regs)
@@ -137,18 +137,16 @@ void watchdog_hardlockup_check(struct pt_regs *regs)
                 * generating interleaving traces
                 */
                if (sysctl_hardlockup_all_cpu_backtrace &&
-                               !test_and_set_bit(0, &hardlockup_allcpu_dumped))
+                   !test_and_set_bit(0, &watchdog_hardlockup_all_cpu_dumped))
                        trigger_allbutself_cpu_backtrace();
 
                if (hardlockup_panic)
                        nmi_panic(regs, "Hard LOCKUP");
 
-               __this_cpu_write(hard_watchdog_warn, true);
-               return;
+               __this_cpu_write(watchdog_hardlockup_warned, true);
+       } else {
+               __this_cpu_write(watchdog_hardlockup_warned, false);
        }
-
-       __this_cpu_write(hard_watchdog_warn, false);
-       return;
 }
 
 #else /* CONFIG_HARDLOCKUP_DETECTOR_PERF */