From 354542d034ab2a849a284edcc661e76b753a57dc Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 9 Jun 2016 06:41:41 -0700 Subject: [PATCH] x86/microcode/intel: Do not issue microcode updates messages on each CPU On large systems the microcode driver is very noisy, because it prints a line for each CPU. The lines are redundant because usually all CPUs are updated to the same microcode revision. All other subsystems have been patched previously to not print a line for each CPU. Only the microcode driver is left. Only print an microcode revision update when something changed. This results in typically only a single line being printed. Signed-off-by: Andi Kleen Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Cc: elliott@hpe.com Cc: hmh@hmh.eng.br Link: http://lkml.kernel.org/r/20160609134141.5981-1-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/microcode/intel.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 8962d6acee39..6515c802346a 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -843,6 +843,7 @@ void reload_ucode_intel(void) static int collect_cpu_info(int cpu_num, struct cpu_signature *csig) { + static struct cpu_signature prev; struct cpuinfo_x86 *c = &cpu_data(cpu_num); unsigned int val[2]; @@ -857,8 +858,13 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig) } csig->rev = c->microcode; - pr_info("CPU%d sig=0x%x, pf=0x%x, revision=0x%x\n", - cpu_num, csig->sig, csig->pf, csig->rev); + + /* No extra locking on prev, races are harmless. */ + if (csig->sig != prev.sig || csig->pf != prev.pf || csig->rev != prev.rev) { + pr_info("sig=0x%x, pf=0x%x, revision=0x%x\n", + csig->sig, csig->pf, csig->rev); + prev = *csig; + } return 0; } @@ -887,6 +893,7 @@ static int apply_microcode_intel(int cpu) struct ucode_cpu_info *uci; struct cpuinfo_x86 *c; unsigned int val[2]; + static int prev_rev; /* We should bind the task to the CPU */ if (WARN_ON(raw_smp_processor_id() != cpu)) @@ -921,11 +928,14 @@ static int apply_microcode_intel(int cpu) return -1; } - pr_info("CPU%d updated to revision 0x%x, date = %04x-%02x-%02x\n", - cpu, val[1], - mc->hdr.date & 0xffff, - mc->hdr.date >> 24, - (mc->hdr.date >> 16) & 0xff); + if (val[1] != prev_rev) { + pr_info("updated to revision 0x%x, date = %04x-%02x-%02x\n", + val[1], + mc->hdr.date & 0xffff, + mc->hdr.date >> 24, + (mc->hdr.date >> 16) & 0xff); + prev_rev = val[1]; + } c = &cpu_data(cpu); -- 2.11.0