Re: [PATCH v4 08/17] watchdog/hardlockup: Style changes to watchdog_hardlockup_check() / ..._is_lockedup()
flat view
From: "Nicholas Piggin" <npiggin@gmail.com>
Date: 2023-05-05 03:03:06
Also in:
linux-arm-kernel, linux-perf-users, sparclinux
On Fri May 5, 2023 at 8:13 AM AEST, Douglas Anderson wrote:
These are tiny style changes: - Add a blank line before a "return". - Renames two globals to use the "watchdog_hld" prefix.
Particularly static ones don't really need the namespace prefixes. Not sure if processed is better than warn. allcpu_dumped is better than dumped_stacks though because the all-CPUs-dump is a particular thing. Other style bits seem fine. Thanks, Nick
quoted hunk ↗ jump to hunk
- Store processor id in "unsigned int" rather than "int". - Minor comment rewording. - Use "else" rather than extra returns since it seemed more symmetric. Signed-off-by: Douglas Anderson <dianders@chromium.org> --- Changes in v4: - ("Style changes to watchdog_hardlockup_check ...") new for v4. kernel/watchdog.c | 32 +++++++++++++++----------------- 1 file changed, 15 insertions(+), 17 deletions(-)diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 2d319cdf64b9..f46669c1671d 100644 --- 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_processed); +static unsigned long watchdog_hardlockup_dumped_stacks; static bool watchdog_hardlockup_is_lockedup(void) {@@ -100,6 +100,7 @@ static bool watchdog_hardlockup_is_lockedup(void) return true; __this_cpu_write(hrtimer_interrupts_saved, hrint); + return false; }@@ -110,21 +111,20 @@ static void watchdog_hardlockup_interrupt_count(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 (watchdog_hardlockup_is_lockedup()) { - 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 handle hardlockups once. */ + if (__this_cpu_read(watchdog_hardlockup_processed)) 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_dumped_stacks)) 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_processed, true); + } else { + __this_cpu_write(watchdog_hardlockup_processed, false); } - - __this_cpu_write(hard_watchdog_warn, false); - return; } #else /* CONFIG_HARDLOCKUP_DETECTOR_PERF */-- 2.40.1.521.gf1e218fcd8-goog