Hi Steven, kernel test robot noticed the following build warnings: [auto build test WARNING on next-20240305] [cannot apply to tip/x86/core akpm-mm/mm-everything linus/master v6.8-rc7 v6.8-rc6 v6.8-rc5 v6.8-rc7] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/ring-buffer-Allow-mapped-field-to-be-set-without-mapping/20240306-100047 base: next-20240305 patch link: https://lore.kernel.org/r/20240306020006.100449500%40goodmis.org patch subject: [PATCH 5/8] ring-buffer: Add ring_buffer_meta data config: sh-defconfig (https://download.01.org/0day-ci/archive/20240308/202403081831.EWSQPo2a-lkp@xxxxxxxxx/config) compiler: sh4-linux-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240308/202403081831.EWSQPo2a-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202403081831.EWSQPo2a-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): kernel/trace/ring_buffer.c: In function 'rb_set_commit_to_write': >> kernel/trace/ring_buffer.c:3224:45: warning: assignment to 'long unsigned int' from 'struct buffer_data_page *' makes integer from pointer without a cast [-Wint-conversion] 3224 | meta->commit_buffer = cpu_buffer->commit_page->page; | ^ vim +3224 kernel/trace/ring_buffer.c 3192 3193 static __always_inline void 3194 rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer) 3195 { 3196 unsigned long max_count; 3197 3198 /* 3199 * We only race with interrupts and NMIs on this CPU. 3200 * If we own the commit event, then we can commit 3201 * all others that interrupted us, since the interruptions 3202 * are in stack format (they finish before they come 3203 * back to us). This allows us to do a simple loop to 3204 * assign the commit to the tail. 3205 */ 3206 again: 3207 max_count = cpu_buffer->nr_pages * 100; 3208 3209 while (cpu_buffer->commit_page != READ_ONCE(cpu_buffer->tail_page)) { 3210 if (RB_WARN_ON(cpu_buffer, !(--max_count))) 3211 return; 3212 if (RB_WARN_ON(cpu_buffer, 3213 rb_is_reader_page(cpu_buffer->tail_page))) 3214 return; 3215 /* 3216 * No need for a memory barrier here, as the update 3217 * of the tail_page did it for this page. 3218 */ 3219 local_set(&cpu_buffer->commit_page->page->commit, 3220 rb_page_write(cpu_buffer->commit_page)); 3221 rb_inc_page(&cpu_buffer->commit_page); 3222 if (cpu_buffer->ring_meta) { 3223 struct ring_buffer_meta *meta = cpu_buffer->ring_meta; > 3224 meta->commit_buffer = cpu_buffer->commit_page->page; 3225 } 3226 /* add barrier to keep gcc from optimizing too much */ 3227 barrier(); 3228 } 3229 while (rb_commit_index(cpu_buffer) != 3230 rb_page_write(cpu_buffer->commit_page)) { 3231 3232 /* Make sure the readers see the content of what is committed. */ 3233 smp_wmb(); 3234 local_set(&cpu_buffer->commit_page->page->commit, 3235 rb_page_write(cpu_buffer->commit_page)); 3236 RB_WARN_ON(cpu_buffer, 3237 local_read(&cpu_buffer->commit_page->page->commit) & 3238 ~RB_WRITE_MASK); 3239 barrier(); 3240 } 3241 3242 /* again, keep gcc from optimizing */ 3243 barrier(); 3244 3245 /* 3246 * If an interrupt came in just after the first while loop 3247 * and pushed the tail page forward, we will be left with 3248 * a dangling commit that will never go forward. 3249 */ 3250 if (unlikely(cpu_buffer->commit_page != READ_ONCE(cpu_buffer->tail_page))) 3251 goto again; 3252 } 3253 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
