This adds the CPU or thread number to printk messages. This can help decipher concurrent oopses that have been interleaved.
Example output, of PID1 (T1) triggering a warning: [ 1.581678][ T1] WARNING: CPU: 0 PID: 1 at crypto/rsa-pkcs1pad.c:539 pkcs1pad_verify+0x38/0x140 [ 1.581681][ T1] Modules linked in: [ 1.581693][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc5-gcc-8.2.0-00121-gf84c2e595927-dirty #1515 [ 1.581700][ T1] NIP: c000000000207d64 LR: c000000000207d3c CTR: c000000000207d2c [ 1.581708][ T1] REGS: c0000000fd2e7560 TRAP: 0700 Not tainted (5.5.0-rc5-gcc-8.2.0-00121-gf84c2e595927-dirty) [ 1.581712][ T1] MSR: 9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 44000222 XER: 00040000 Signed-off-by: Michael Ellerman <m...@ellerman.id.au> --- arch/powerpc/configs/skiroot_defconfig | 1 + 1 file changed, 1 insertion(+) v2: New. diff --git a/arch/powerpc/configs/skiroot_defconfig b/arch/powerpc/configs/skiroot_defconfig index ca6f1842aa29..ae1d7137a84e 100644 --- a/arch/powerpc/configs/skiroot_defconfig +++ b/arch/powerpc/configs/skiroot_defconfig @@ -294,6 +294,7 @@ CONFIG_LIBCRC32C=y # CONFIG_XZ_DEC_ARMTHUMB is not set # CONFIG_XZ_DEC_SPARC is not set CONFIG_PRINTK_TIME=y +CONFIG_PRINTK_CALLER=y CONFIG_MAGIC_SYSRQ=y CONFIG_SLUB_DEBUG_ON=y CONFIG_SCHED_STACK_END_CHECK=y -- 2.21.1