linux-kernel - Re: [PATCH] x86/mce/dev-mcelog: Call mce_register_decode

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Date:   Fri, 20 Aug 2021 14:28:45 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Tony Luck <tony.luck@...el.com>
Cc:     x86@...nel.org, linux-edac@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Sumanth Kamatala <skamatala@...iper.net>
Subject: Re: [PATCH] x86/mce/dev-mcelog: Call mce_register_decode_chain()
 much earlier

On Thu, Aug 19, 2021 at 03:44:52PM -0700, Tony Luck wrote:
> which made sure that the logs were not lost completely by printing
> to the console. But parsing console logs is error prone. Users
> of /dev/mcelog should expect to find any early errors logged to
> standard places.

Yes, and for that matter, *all* consumers which register on the decoding
chain should get a chance to look at those records...

> Split the initialization code in dev-mcelog.c into:
> 1) an "early" part that registers for mce notifications. Call this
> directly from mcheck_init() because early_initcall() is still too late.
> This allocation is too early for kzalloc() so use memblock_alloc().
> 2) "late" part that registers the /dev/mcelog character device.

... but this looks like a hack to me: why aren't we adding those early
records to the gen_pool and kick the work to consume them *only* *after*
all consumers have been registered properly and everything is up and
running?

Thx.

-- 
Regards/Gruss,
    Boris.

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