Hello, kernel test robot noticed "BUG:KCSAN:data-race_in__percpu_counter_limited_add/__percpu_counter_limited_add" on: commit: beb9868628445306958fd7b2da1cd369a4a381cc ("shmem,percpu_counter: add _limited_add(fbc, limit, amount)") https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master [test failed on linus/master 2bfcfd584ff5ccc8bb7acde19b42570414bf880b] [test failed on linux-next/master 6dc544b66971c7f9909ff038b62149105272d26a] in testcase: trinity version: with following parameters: runtime: 300s group: group-01 nr_groups: 5 compiler: gcc-12 test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G (please refer to attached dmesg/kmsg for entire log/backtrace) in our tests, dmesg.BUG:KCSAN:data-race_in__percpu_counter_limited_add/__percpu_counter_limited_add does not always happen, 88 times out of 150 runs as below. 3022fd7af9604d44 beb9868628445306958fd7b2da1 ---------------- --------------------------- fail:runs %reproduction fail:runs | | | :60 147% 88:150 dmesg.BUG:KCSAN:data-race_in__percpu_counter_limited_add/__percpu_counter_limited_add 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 <oliver.sang@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-lkp/202405311100.d46f2cc1-lkp@xxxxxxxxx [ 301.127451][ T4651] ================================================================== [ 301.128485][ T4651] BUG: KCSAN: data-race in __percpu_counter_limited_add / __percpu_counter_limited_add [ 301.129715][ T4651] [ 301.130014][ T4651] write to 0xffff88810ffc3450 of 8 bytes by task 4674 on cpu 0: [ 301.130981][ T4651] __percpu_counter_limited_add (lib/percpu_counter.c:325) [ 301.131692][ T4651] shmem_inode_acct_blocks (mm/shmem.c:220) [ 301.132319][ T4651] shmem_get_folio_gfp+0x3a9/0x750 [ 301.133054][ T4651] shmem_write_begin (mm/shmem.c:2135 mm/shmem.c:2692) [ 301.133690][ T4651] generic_perform_write (mm/filemap.c:3962) [ 301.134347][ T4651] shmem_file_write_iter (mm/shmem.c:2868) [ 301.134956][ T4651] do_iter_readv_writev (include/linux/fs.h:1956 fs/read_write.c:735) [ 301.135628][ T4651] do_iter_write (fs/read_write.c:860) [ 301.136178][ T4651] vfs_writev (fs/read_write.c:933) [ 301.136716][ T4651] __x64_sys_pwritev2 (fs/read_write.c:1030 fs/read_write.c:1089 fs/read_write.c:1080 fs/read_write.c:1080) [ 301.139719][ T4651] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [ 301.140316][ T4651] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) [ 301.141129][ T4651] [ 301.141465][ T4651] read to 0xffff88810ffc3450 of 8 bytes by task 4651 on cpu 1: [ 301.142436][ T4651] __percpu_counter_limited_add (lib/percpu_counter.c:302 (discriminator 1)) [ 301.143222][ T4651] shmem_inode_acct_blocks (mm/shmem.c:220) [ 301.143931][ T4651] shmem_get_folio_gfp+0x3a9/0x750 [ 301.144696][ T4651] shmem_write_begin (mm/shmem.c:2135 mm/shmem.c:2692) [ 301.145370][ T4651] generic_perform_write (mm/filemap.c:3962) [ 301.146112][ T4651] shmem_file_write_iter (mm/shmem.c:2868) [ 301.146697][ T4651] do_iter_readv_writev (include/linux/fs.h:1956 fs/read_write.c:735) [ 301.147330][ T4651] do_iter_write (fs/read_write.c:860) [ 301.147918][ T4651] vfs_writev (fs/read_write.c:933) [ 301.148480][ T4651] __x64_sys_pwritev2 (fs/read_write.c:1030 fs/read_write.c:1089 fs/read_write.c:1080 fs/read_write.c:1080) [ 301.149047][ T4651] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [ 301.149629][ T4651] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) [ 301.150358][ T4651] [ 301.150643][ T4651] value changed: 0x0000000000059e35 -> 0x0000000000059e56 [ 301.151483][ T4651] [ 301.151778][ T4651] Reported by Kernel Concurrency Sanitizer on: [ 301.152559][ T4651] CPU: 1 PID: 4651 Comm: trinity-c7 Not tainted 6.6.0-rc4-00235-gbeb986862844 #1 [ 301.153676][ T4651] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 301.154962][ T4651] ================================================================== ... [ 341.345671][ T4958] ================================================================== [ 341.346844][ T4958] BUG: KCSAN: data-race in __percpu_counter_limited_add / __percpu_counter_limited_add [ 341.348131][ T4958] [ 341.348468][ T4958] write to 0xffff88810ffc3450 of 8 bytes by task 4967 on cpu 0: [ 341.349472][ T4958] __percpu_counter_limited_add (lib/percpu_counter.c:325) [ 341.350219][ T4958] shmem_inode_acct_blocks (mm/shmem.c:220) [ 341.350902][ T4958] shmem_get_folio_gfp+0x3a9/0x750 [ 341.351630][ T4958] shmem_write_begin (mm/shmem.c:2135 mm/shmem.c:2692) [ 341.352270][ T4958] generic_perform_write (mm/filemap.c:3962) [ 341.352893][ T4958] shmem_file_write_iter (mm/shmem.c:2868) [ 341.353521][ T4958] do_iter_readv_writev (include/linux/fs.h:1956 fs/read_write.c:735) [ 341.354170][ T4958] do_iter_write (fs/read_write.c:860) [ 341.354738][ T4958] vfs_writev (fs/read_write.c:933) [ 341.355289][ T4958] __x64_sys_pwritev2 (fs/read_write.c:1030 fs/read_write.c:1089 fs/read_write.c:1080 fs/read_write.c:1080) [ 341.355926][ T4958] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [ 341.356511][ T4958] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) [ 341.357277][ T4958] [ 341.357592][ T4958] read to 0xffff88810ffc3450 of 8 bytes by task 4958 on cpu 1: [ 341.358556][ T4958] __percpu_counter_limited_add (lib/percpu_counter.c:302 (discriminator 1)) [ 341.359312][ T4958] shmem_inode_acct_blocks (mm/shmem.c:220) [ 341.360021][ T4958] shmem_get_folio_gfp+0x3a9/0x750 [ 341.360772][ T4958] shmem_write_begin (mm/shmem.c:2135 mm/shmem.c:2692) [ 341.361417][ T4958] generic_perform_write (mm/filemap.c:3962) [ 341.362106][ T4958] shmem_file_write_iter (mm/shmem.c:2868) [ 341.362751][ T4958] do_iter_readv_writev (include/linux/fs.h:1956 fs/read_write.c:735) [ 341.363443][ T4958] do_iter_write (fs/read_write.c:860) [ 341.364025][ T4958] vfs_writev (fs/read_write.c:933) [ 341.364585][ T4958] __x64_sys_pwritev2 (fs/read_write.c:1030 fs/read_write.c:1089 fs/read_write.c:1080 fs/read_write.c:1080) [ 341.365226][ T4958] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [ 341.365824][ T4958] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) [ 341.366587][ T4958] [ 341.366921][ T4958] value changed: 0x000000000008c0e8 -> 0x000000000008c109 [ 341.367883][ T4958] [ 341.368191][ T4958] Reported by Kernel Concurrency Sanitizer on: [ 341.369014][ T4958] CPU: 1 PID: 4958 Comm: trinity-c5 Not tainted 6.6.0-rc4-00235-gbeb986862844 #1 [ 341.370255][ T4958] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 341.371512][ T4958] ================================================================== The kernel config and materials to reproduce are available at: https://download.01.org/0day-ci/archive/20240531/202405311100.d46f2cc1-lkp@xxxxxxxxx -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki