linux-edac.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Borislav Petkov <bp@alien8.de>
To: William Roche <william.roche@oracle.com>
Cc: linux-kernel@vger.kernel.org, Tony Luck <tony.luck@intel.com>,
	linux-edac@vger.kernel.org
Subject: Re: [PATCH v1] RAS/CEC: Memory Corrected Errors consistent event filtering
Date: Fri, 26 Mar 2021 23:43:10 +0100	[thread overview]
Message-ID: <20210326224310.GL25229@zn.tnic> (raw)
In-Reply-To: <fac89612-e15c-2940-9d6d-70a812dbe99c@oracle.com>

On Fri, Mar 26, 2021 at 11:24:43PM +0100, William Roche wrote:
> What we want is to make cec_add_elem() to return !0 value only
> when the given pfn triggered an action, so that its callers should
> log the error.

No, this is not what the CEC does - it collects those errors and when it
reaches the threshold for any pfn, it offlines the corresponding page. I
know, the comment above talks about:

  * That error event entry causes cec_add_elem() to return !0 value and thus
  * signal to its callers to log the error.

but it doesn't do that. Frankly, I don't see the point of logging the
error - it already says

	pr_err("Soft-offlining pfn: 0x%llx\n", pfn);

which pfn it has offlined. And that is probably only mildly interesting
to people - so what, 4K got offlined, servers have so much memory
nowadays.

The only moment one should start worrying is if one gets those pretty
often but then you're probably better off simply scheduling maintenance
and replacing the faulty DIMM - problem solved.

> What I'm expecting from ras_cec is to "hide" CEs until they reach the
> action threshold where an action is tried against the impacted PFN,

That it does.

> and it's now the time to log the error with the entire notifiers
> chain.

And I'm not sure why we'd want to do that. It simply offlines the page.

But maybe you could explain what you're trying to achieve...

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

  reply	other threads:[~2021-03-26 22:43 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-26 18:30 [PATCH v1] RAS/CEC: Memory Corrected Errors consistent event filtering “William Roche
2021-03-26 19:02 ` Borislav Petkov
2021-03-26 22:24   ` William Roche
2021-03-26 22:43     ` Borislav Petkov [this message]
2021-03-29  9:44       ` William Roche
2021-04-01 16:12         ` Borislav Petkov
2021-04-02 16:00           ` William Roche
2021-04-02 17:07             ` Borislav Petkov
2021-04-06 15:28               ` [PATCH v2] " “William Roche

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210326224310.GL25229@zn.tnic \
    --to=bp@alien8.de \
    --cc=linux-edac@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tony.luck@intel.com \
    --cc=william.roche@oracle.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).