Re: [PATCH 6/8] SGI x86_64 UV: Limit the number of microcode messages

From: Mike Travis
Date: Mon Oct 26 2009 - 14:18:48 EST




Dmitry Adamushko wrote:
2009/10/24 Mike Travis <travis@xxxxxxx>:
Limit number of microcode messages of the form:

[ 50.887135] microcode: CPU0 sig=0x206e5, pf=0x4, revision=0xffff001

[ ... ]

--- linux.orig/arch/x86/kernel/microcode_intel.c
+++ linux/arch/x86/kernel/microcode_intel.c
@@ -165,7 +165,9 @@
/* get the current revision from MSR 0x8B */
rdmsr(MSR_IA32_UCODE_REV, val[0], csig->rev);

- printk(KERN_INFO "microcode: CPU%d sig=0x%x, pf=0x%x, revision=0x%x\n",
+ if (cpu_num < 4 || !limit_console_output(false))
+ printk(KERN_INFO
+ "microcode: CPU%d sig=0x%x, pf=0x%x, revision=0x%x\n",
cpu_num, csig->sig, csig->pf, csig->rev);


Hmm, I guess we wouldn't lose a lot by simply removing those messages
completely. Per-cpu pf/revision is available via /sys anyway.

Alternatively, we might move the output into
microcode_core.c::collect_cpu_info() (or even microcode_init_cpu()) so
that the same logic is also applied for amd and do something as
following:

don't print if a cpu info is equal to the info of CPU#0. I guess, any
non-0 cpu would be even better as the microcode for cpu#0 can be
loaded by BIOS, if I'm not mistaken. But then we can only be sure
about the presence of cpu#0.

Anyway, it's not worthy of any additional complexity so I'd say let's
just remove the output :-)


-- Dmitry

I would be more than happy to remove messages but I didn't want to override
the original author's intent on why they choose to add these messages in the
first place.

Plus if you have a 64 or 128 cpu system, it might give you pleasure in seeing
all those cpu messages. ;-) Just when it hits around 256 and up that it
really starts getting annoying.

Thanks,
Mike

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