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Date: Thu, 9 Jun 2016 06:41:41 -0700 From: Andi Kleen <andi@...stfloor.org> To: x86@...nel.org Cc: hmh@....eng.br, elliott@....com, linux-kernel@...r.kernel.org, Andi Kleen <ak@...ux.intel.com> Subject: [PATCH] x86/microcode/intel: Quieten down microcode updates on large systems From: Andi Kleen <ak@...ux.intel.com> On large systems the microcode driver is very noisy, because it prints a line for each CPU. The lines are redundant because 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. v2: Change message to "One or more CPUs" Signed-off-by: Andi Kleen <ak@...ux.intel.com> --- arch/x86/kernel/cpu/microcode/intel.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index cbb3cf0..54f5f6c 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -794,6 +794,7 @@ 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]; @@ -808,8 +809,14 @@ 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("One or more CPUs sig=0x%x, pf=0x%x, revision=0x%x\n", + csig->sig, csig->pf, csig->rev); + prev = *csig; + } return 0; } @@ -838,6 +845,7 @@ 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)) @@ -872,11 +880,14 @@ 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("One or more CPUs 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); -- 2.8.3
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