Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk()

From	"Kani, Toshimitsu" <toshi.kani@hpe.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk()
Date	2017-08-14 20:00 +0200
Message-ID	<uerOF-79Q-7@gated-at.bofh.it> (permalink)
References	(6 earlier) <ude77-1CC-5@gated-at.bofh.it> <uepWy-60G-33@gated-at.bofh.it> <ueqpA-6qC-33@gated-at.bofh.it> <ueqIW-6xI-25@gated-at.bofh.it> <uer2h-6Tj-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, 2017-08-14 at 19:05 +0200, Borislav Petkov wrote:
> On Mon, Aug 14, 2017 at 04:48:57PM +0000, Kani, Toshimitsu wrote:
> > Right, but the issue is how [ghes_edac_]report_mem_error() protects
> > from possible concurrent calls from multiple GHES sources when
> > there is only a single mci.
> 
> Do you know of an actual firmware reporting multiple errors
> concurrently?

I do not know.  We have multiple GHES entries, but they all use SCI. 
Since ACPICA uses a single threaded workqueue for notify handlers, they
are serialized among SCIs.

ACPI 6.2 defines multiple notification types in Table 18-383, and
ghes_proc() can be called from ghes_poll_func(), ghes_irq_func(), and
ghes_notify_sci().  So, I think it is safe to operate per an entry
basis.

> GHES v2 even needs to ACK the current error first before it can read
> the next one.

Yes, but this ACK is done per a GHES entry as well.

Thanks,
-Toshi

Thread

Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-14 18:00 +0200
  Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-14 18:30 +0200
    Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-14 18:50 +0200
      Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-14 19:10 +0200
        Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-14 20:00 +0200
          Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-14 20:10 +0200
            Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-14 20:20 +0200
              Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-14 20:40 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-14 21:10 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-14 21:40 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-14 22:20 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-14 22:40 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-15 17:40 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Luck, Tony" <tony.luck@intel.com> - 2017-08-15 17:50 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-15 18:00 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-16 10:30 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-16 13:30 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Steven Rostedt <rostedt@goodmis.org> - 2017-08-16 16:00 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-16 16:10 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Steven Rostedt <rostedt@goodmis.org> - 2017-08-16 16:30 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-16 19:40 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-16 17:30 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-16 18:50 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-16 19:30 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-16 19:50 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-16 20:10 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-17 23:10 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-21 11:30 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() Borislav Petkov <bp@alien8.de> - 2017-08-15 18:00 +0200
                Re: [PATCH v2 4/7] ghes_edac: avoid multiple calls to dmi_walk() "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2017-08-15 18:30 +0200

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