Hi Matthew,

I love your patch! Yet something to improve:

[auto build test ERROR on rcu/rcu/next]
[also build test ERROR on v4.16-rc6 next-20180323]
[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/Matthew-Wilcox/Add-free-function/20180324-140756
base:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/next
config: s390-default_defconfig (attached as .config)
compiler: s390x-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
        make.cross ARCH=s390 

All errors (new ones prefixed by >>):

>> drivers/s390/cio/blacklist.c:43:20: error: 'free' redeclared as different kind of symbol
    typedef enum {add, free} range_action;
                       ^~~~
   In file included from include/linux/list.h:9:0,
                    from include/linux/preempt.h:11,
                    from include/linux/spinlock.h:51,
                    from include/linux/vmalloc.h:5,
                    from drivers/s390/cio/blacklist.c:15:
   include/linux/kernel.h:935:6: note: previous declaration of 'free' was here
    void free(const void *);
         ^~~~

vim +/free +43 drivers/s390/cio/blacklist.c

^1da177e Linus Torvalds 2005-04-16  30  
^1da177e Linus Torvalds 2005-04-16  31  /*
^1da177e Linus Torvalds 2005-04-16  32   * "Blacklisting" of certain devices:
^1da177e Linus Torvalds 2005-04-16  33   * Device numbers given in the commandline as cio_ignore=... won't be known
^1da177e Linus Torvalds 2005-04-16  34   * to Linux.
^1da177e Linus Torvalds 2005-04-16  35   *
^1da177e Linus Torvalds 2005-04-16  36   * These can be single devices or ranges of devices
^1da177e Linus Torvalds 2005-04-16  37   */
^1da177e Linus Torvalds 2005-04-16  38  
fb6958a5 Cornelia Huck  2006-01-06  39  /* 65536 bits for each set to indicate if a devno is blacklisted or not */
a8237fc4 Cornelia Huck  2006-01-06  40  #define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
^1da177e Linus Torvalds 2005-04-16  41  			 (8*sizeof(long)))
fb6958a5 Cornelia Huck  2006-01-06  42  static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
^1da177e Linus Torvalds 2005-04-16 @43  typedef enum {add, free} range_action;
^1da177e Linus Torvalds 2005-04-16  44  

:::::: The code at line 43 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2

:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>

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