linux-kernel - [PATCH v9 0/3] Handle corrected machine check interrupt storms

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Date:   Wed,  4 Oct 2023 11:36:20 -0700
From:   Tony Luck <tony.luck@...el.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Yazen Ghannam <yazen.ghannam@....com>,
        Smita.KoralahalliChannabasappa@....com,
        dave.hansen@...ux.intel.com, x86@...nel.org,
        linux-edac@...r.kernel.org, linux-kernel@...r.kernel.org,
        patches@...ts.linux.dev, Tony Luck <tony.luck@...el.com>
Subject: [PATCH v9 0/3] Handle corrected machine check interrupt storms

Linux CMCI storm mitigation is a big hammer that just disables the CMCI
interrupt globally and switches to polling all banks.

There are two problems with this:
1) It really is a big hammer. It means that errors reported in other
banks from different functional units are all subject to the same
polling delay before being processed.
2) Intel systems signal some uncorrected errors using CMCI (e.g.
memory controller patrol scrub on Icelake Xeon and newer). Delaying
processing these error reports negates some of the benefit of the patrol
scrubber providing early notice of errors before they are consumed and
cause a machine check.

This series throws away the old storm implementation and replaces it
with one that keeps track of the weather on each separate machine check
bank. When a storm is detected from a bank. On Intel the storm is
mitigated by setting a very high threshold for corrected errors to
signal CMCI. This threshold does not affect signaling CMCI for
uncorrected errors.

Signed-off-by: Tony Luck <tony.luck@...el.com>

---

Changes since v8:

Fixed issue reported by lkp with randconfig build with neither
CONFIG_X86_MCE_INTEL not CONFIG_X86_MCE_AMD set by making a
cleaner division between the storm tracking code in threshold.c
with the restof the code using more function accessors that can
be stubbed out.

Tony Luck (3):
  x86/mce: Remove old CMCI storm mitigation code
  x86/mce: Add per-bank CMCI storm mitigation
  x86/mce: Handle Intel threshold interrupt storms

 arch/x86/kernel/cpu/mce/internal.h  |  48 ++++-
 arch/x86/kernel/cpu/mce/core.c      |  45 ++---
 arch/x86/kernel/cpu/mce/intel.c     | 303 ++++++++++++----------------
 arch/x86/kernel/cpu/mce/threshold.c | 115 +++++++++++
 4 files changed, 304 insertions(+), 207 deletions(-)

base-commit: 6465e260f48790807eef06b583b38ca9789b6072
-- 
2.41.0