Hi Rik,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tip/sched/core]
[also build test ERROR on linux/master linus/master v5.12-rc8 next-20210416]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Rik-van-Riel/sched-fair-skip-newidle_balance-if-a-wakeup-is-pending/20210419-101843
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 9406415f46f6127fd31bb66f0260f7a61a8d2786
config: riscv-randconfig-r025-20210419 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 2b50f5a4343f8fb06acaa5c36355bcf58092c9cd)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/3f6b55f5258c8d8d217e8b8408de056a20745824
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Rik-van-Riel/sched-fair-skip-newidle_balance-if-a-wakeup-is-pending/20210419-101843
        git checkout 3f6b55f5258c8d8d217e8b8408de056a20745824
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/tick.h:8:
   In file included from include/linux/clockchips.h:14:
   In file included from include/linux/clocksource.h:21:
   In file included from arch/riscv/include/asm/io.h:149:
   include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inw(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:88:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro '__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   In file included from kernel/sched/fair.c:23:
   In file included from kernel/sched/sched.h:17:
   In file included from include/linux/sched/isolation.h:6:
   In file included from include/linux/tick.h:8:
   In file included from include/linux/clockchips.h:14:
   In file included from include/linux/clocksource.h:21:
   In file included from arch/riscv/include/asm/io.h:149:
   include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inl(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:57:76: note: expanded from macro 'inl'
   #define inl(c)          ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:89:76: note: expanded from macro 'readl_cpu'
   #define readl_cpu(c)            ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro '__le32_to_cpu'
   #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
                                                     ^
   In file included from kernel/sched/fair.c:23:
   In file included from kernel/sched/sched.h:17:
   In file included from include/linux/sched/isolation.h:6:
   In file included from include/linux/tick.h:8:
   In file included from include/linux/clockchips.h:14:
   In file included from include/linux/clocksource.h:21:
   In file included from arch/riscv/include/asm/io.h:149:
   include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outb(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outb'
   #define outb(v,c)       ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:91:52: note: expanded from macro 'writeb_cpu'
   #define writeb_cpu(v, c)        ((void)__raw_writeb((v), (c)))
                                                             ^
   In file included from kernel/sched/fair.c:23:
   In file included from kernel/sched/sched.h:17:
   In file included from include/linux/sched/isolation.h:6:
   In file included from include/linux/tick.h:8:
   In file included from include/linux/clockchips.h:14:
   In file included from include/linux/clocksource.h:21:
   In file included from arch/riscv/include/asm/io.h:149:
   include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outw(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outw'
   #define outw(v,c)       ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:92:76: note: expanded from macro 'writew_cpu'
   #define writew_cpu(v, c)        ((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
                                                                                     ^
   In file included from kernel/sched/fair.c:23:
   In file included from kernel/sched/sched.h:17:
   In file included from include/linux/sched/isolation.h:6:
   In file included from include/linux/tick.h:8:
   In file included from include/linux/clockchips.h:14:
   In file included from include/linux/clocksource.h:21:
   In file included from arch/riscv/include/asm/io.h:149:
   include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outl(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:61:68: note: expanded from macro 'outl'
   #define outl(v,c)       ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:93:76: note: expanded from macro 'writel_cpu'
   #define writel_cpu(v, c)        ((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
                                                                                     ^
   In file included from kernel/sched/fair.c:23:
   In file included from kernel/sched/sched.h:17:
   In file included from include/linux/sched/isolation.h:6:
   In file included from include/linux/tick.h:8:
   In file included from include/linux/clockchips.h:14:
   In file included from include/linux/clocksource.h:21:
   In file included from arch/riscv/include/asm/io.h:149:
   include/asm-generic/io.h:1005:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
                                                     ~~~~~~~~~~ ^
   kernel/sched/fair.c:637:5: warning: no previous prototype for function 'sched_update_scaling' [-Wmissing-prototypes]
   int sched_update_scaling(void)
       ^
   kernel/sched/fair.c:637:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int sched_update_scaling(void)
   ^
   static 
>> kernel/sched/fair.c:7208:10: error: no member named 'ttwu_pending' in 'struct rq'
           if (rq->ttwu_pending)
               ~~  ^
   8 warnings and 1 error generated.


vim +7208 kernel/sched/fair.c

  7191	
  7192		if (hrtick_enabled_fair(rq))
  7193			hrtick_start_fair(rq, p);
  7194	
  7195		update_misfit_status(p, rq);
  7196	
  7197		return p;
  7198	
  7199	idle:
  7200		if (!rf)
  7201			return NULL;
  7202	
  7203		/*
  7204		 * We have a woken up task pending here. No need to search for ones
  7205		 * elsewhere. This task will be enqueued the moment we unblock irqs
  7206		 * upon exiting the scheduler.
  7207		 */
> 7208		if (rq->ttwu_pending)
  7209			return NULL;
  7210	
  7211		new_tasks = newidle_balance(rq, rf);
  7212	
  7213		/*
  7214		 * Because newidle_balance() releases (and re-acquires) rq->lock, it is
  7215		 * possible for any higher priority task to appear. In that case we
  7216		 * must re-start the pick_next_entity() loop.
  7217		 */
  7218		if (new_tasks < 0)
  7219			return RETRY_TASK;
  7220	
  7221		if (new_tasks > 0)
  7222			goto again;
  7223	
  7224		/*
  7225		 * rq is about to be idle, check if we need to update the
  7226		 * lost_idle_time of clock_pelt
  7227		 */
  7228		update_idle_rq_clock_pelt(rq);
  7229	
  7230		return NULL;
  7231	}
  7232	

---
0-DAY CI Kernel Test Service, Intel Corporation
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