tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 0da0a8a0a0e1845f495431c3d8d733d2bbf9e9e5 commit: 6d25a633ea68a103c7293d16eb69a7d4689075ad lib: Prepare zstd for preboot environment, improve performance date: 6 months ago config: parisc-randconfig-r026-20210117 (attached as .config) compiler: hppa-linux-gcc (GCC) 9.3.0 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 # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 6d25a633ea68a103c7293d16eb69a7d4689075ad # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): lib/zstd/compress.c:434:8: warning: no previous prototype for 'ZSTD_noCompressBlock' [-Wmissing-prototypes] 434 | size_t ZSTD_noCompressBlock(void *dst, size_t dstCapacity, const void *src, size_t srcSize) | ^~~~~~~~~~~~~~~~~~~~ lib/zstd/compress.c:2252:6: warning: no previous prototype for 'ZSTD_compressBlock_greedy_extDict' [-Wmissing-prototypes] 2252 | void ZSTD_compressBlock_greedy_extDict(ZSTD_CCtx *ctx, const void *src, size_t srcSize) { ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 0); } | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/zstd/compress.c:2982:15: warning: no previous prototype for 'ZSTD_createCStream_advanced' [-Wmissing-prototypes] 2982 | ZSTD_CStream *ZSTD_createCStream_advanced(ZSTD_customMem customMem) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from lib/zstd/compress.c:23: lib/zstd/zstd_internal.h:83:21: warning: 'ZSTD_did_fieldSize' defined but not used [-Wunused-const-variable=] 83 | static const size_t ZSTD_did_fieldSize[4] = {0, 1, 2, 4}; | ^~~~~~~~~~~~~~~~~~ lib/zstd/zstd_internal.h:82:21: warning: 'ZSTD_fcs_fieldSize' defined but not used [-Wunused-const-variable=] 82 | static const size_t ZSTD_fcs_fieldSize[4] = {0, 2, 4, 8}; | ^~~~~~~~~~~~~~~~~~ In file included from lib/zstd/error_private.h:26, from lib/zstd/bitstream.h:53, from lib/zstd/fse.h:228, from lib/zstd/compress.c:20: include/linux/zstd.h:798:21: warning: 'ZSTD_skippableHeaderSize' defined but not used [-Wunused-const-variable=] 798 | static const size_t ZSTD_skippableHeaderSize = 8; | ^~~~~~~~~~~~~~~~~~~~~~~~ include/linux/zstd.h:795:21: warning: 'ZSTD_frameHeaderSize_min' defined but not used [-Wunused-const-variable=] 795 | static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN; | ^~~~~~~~~~~~~~~~~~~~~~~~ include/linux/zstd.h:794:21: warning: 'ZSTD_frameHeaderSize_prefix' defined but not used [-Wunused-const-variable=] 794 | static const size_t ZSTD_frameHeaderSize_prefix = 5; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/zstd/compress.c: In function 'ZSTD_compressBlock_doubleFast': 1393 | } | ^ vim +1393 lib/zstd/compress.c 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1382 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1383 static void ZSTD_compressBlock_doubleFast(ZSTD_CCtx *ctx, const void *src, size_t srcSize) 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1384 { 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1385 const U32 mls = ctx->params.cParams.searchLength; 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1386 switch (mls) { 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1387 default: /* includes case 3 */ 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1388 case 4: ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 4); return; 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1389 case 5: ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 5); return; 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1390 case 6: ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 6); return; 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1391 case 7: ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 7); return; 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1392 } 73f3d1b48f5069d4 Nick Terrell 2017-08-09 @1393 } 73f3d1b48f5069d4 Nick Terrell 2017-08-09 1394 :::::: The code at line 1393 was first introduced by commit :::::: 73f3d1b48f5069d46ba48aa28c2898dc93185560 lib: Add zstd modules :::::: TO: Nick Terrell <terrelln(a)fb.com&gt; :::::: CC: Chris Mason <clm(a)fb.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org