[PATCH 2/2] powerpc/time: Only cap decrementer when watchdog is enabled

[kbuild test robot]

Hi Anton,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.19-rc5 next-20180928]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Anton-Blanchard/powerpc-time-Use-clockevents_register_device-fixing-an-issue-with-large-decrementer/20180929-093322
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-allnoconfig (attached as .config)
compiler: powerpc-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.2.0 make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

   arch/powerpc/kernel/time.c: In function 'timer_interrupt':
>> arch/powerpc/kernel/time.c:580:44: error: 'watchdog_cpumask' undeclared (first use in this function); did you mean 'proc_watchdog_cpumask'?
         cpumask_test_cpu(smp_processor_id(), &watchdog_cpumask))
                                               ^~~~~~~~~~~~~~~~
                                               proc_watchdog_cpumask
   arch/powerpc/kernel/time.c:580:44: note: each undeclared identifier is reported only once for each function it appears in

vim +580 arch/powerpc/kernel/time.c

   549	
   550	/*
   551	 * timer_interrupt - gets called when the decrementer overflows,
   552	 * with interrupts disabled.
   553	 */
   554	void timer_interrupt(struct pt_regs *regs)
   555	{
   556		struct clock_event_device *evt = this_cpu_ptr(&decrementers);
   557		u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
   558		struct pt_regs *old_regs;
   559		u64 now;
   560	
   561		/* Some implementations of hotplug will get timer interrupts while
   562		 * offline, just ignore these and we also need to set
   563		 * decrementers_next_tb as MAX to make sure __check_irq_replay
   564		 * don't replay timer interrupt when return, otherwise we'll trap
   565		 * here infinitely :(
   566		 */
   567		if (unlikely(!cpu_online(smp_processor_id()))) {
   568			*next_tb = ~(u64)0;
   569			set_dec(decrementer_max);
   570			return;
   571		}
   572	
   573		/* Ensure a positive value is written to the decrementer, or else
   574		 * some CPUs will continue to take decrementer exceptions. When the
   575		 * PPC_WATCHDOG (decrementer based) is configured, keep this at most
   576		 * 31 bits, which is about 4 seconds on most systems, which gives
   577		 * the watchdog a chance of catching timer interrupt hard lockups.
   578		 */
   579		if (IS_ENABLED(CONFIG_PPC_WATCHDOG) &&
 > 580		    cpumask_test_cpu(smp_processor_id(), &watchdog_cpumask))
   581			set_dec(0x7fffffff);
   582		else
   583			set_dec(decrementer_max);
   584	
   585		/* Conditionally hard-enable interrupts now that the DEC has been
   586		 * bumped to its maximum value
   587		 */
   588		may_hard_irq_enable();
   589	
   590	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
-------------- next part --------------
A non-text attachment was scrubbed...
Name: .config.gz
Type: application/gzip
Size: 5832 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20180929/8d938211/attachment.gz>