Hi Yang, Thank you for the patch! Yet something to improve: [auto build test ERROR on dm/for-next] [also build test ERROR on v5.12-rc2 next-20210309] [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/Yang-Li/dm-remove-unneeded-variable-sz/20210309-173431 base: https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git for-next config: x86_64-rhel-7.6-kselftests (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/a0feb390ae71f527ea5582a23afa1889bba31eab git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Yang-Li/dm-remove-unneeded-variable-sz/20210309-173431 git checkout a0feb390ae71f527ea5582a23afa1889bba31eab # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): In file included from drivers/md/dm.h:14, from drivers/md/dm-ps-service-time.c:11: drivers/md/dm-ps-service-time.c: In function 'st_status': >> include/linux/device-mapper.h:588:22: error: 'sz' undeclared (first use in this function); did you mean 's8'? 588 | #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ | ^~ drivers/md/dm-ps-service-time.c:88:3: note: in expansion of macro 'DMEMIT' 88 | DMEMIT("0 "); | ^~~~~~ include/linux/device-mapper.h:588:22: note: each undeclared identifier is reported only once for each function it appears in 588 | #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ | ^~ drivers/md/dm-ps-service-time.c:88:3: note: in expansion of macro 'DMEMIT' 88 | DMEMIT("0 "); | ^~~~~~ vim +588 include/linux/device-mapper.h 0da336e5fab75c Alasdair G Kergon 2008-04-24 587 0da336e5fab75c Alasdair G Kergon 2008-04-24 @588 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \ 0da336e5fab75c Alasdair G Kergon 2008-04-24 589 0 : scnprintf(result + sz, maxlen - sz, x)) 0da336e5fab75c Alasdair G Kergon 2008-04-24 590 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org