Re: [PATCH 02/10] MCE: save most severe error information

Hidetoshi Seto
2011-06-10T08:07:25Z

(2011/06/10 6:30), Luck, Tony wrote:
> From: Tony Luck <tony.luck@intel.com>
>
> monarch clears all of the per cpu "mces_seen", so we must keep a copy
> to use after mce_end()

Could you clarify why we have to use mces_seen after mce_end(), please?

>
> Signed-off-by: Tony Luck <tony.luck@intel.com>
> ---
> arch/x86/kernel/cpu/mcheck/mce.c | 5 ++++-
> 1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
> index 3385ea2..ed1542a 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce.c
> @@ -1046,6 +1046,9 @@ void do_machine_check(struct pt_regs *regs, long error_code)
> }
> }
>
> + /* Save our worst error locally, monarch will clear mces_seen */
> + m = *final;
> +
> if (!no_way_out)
> mce_clear_state(toclear);
>
> @@ -1064,7 +1067,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
> * support MCE broadcasting or it has been disabled.
> */
> if (no_way_out && tolerant < 3)
> - mce_panic("Fatal machine check on current CPU", final, msg);
> + mce_panic("Fatal machine check on current CPU", &m, msg);
>
> /*
> * If the error seems to be unrecoverable, something should be

At least the mce_panic here is called only when there is no monarch
due to no broadcast or failed rendezvous. Otherwise if there is a monarch,
the monarch should check all "mces_seen" before clearing them and call
a single mce_panic() for the system from mce_end() by itself, rather than
having multiple mce_panic() from some of subjects after mce_end().

Thanks,
H.Seto