From: Anton Blanchard <anton@samba.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: jkenisto@us.ibm.com, paulus@samba.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/nvram: Add spinlock to oops_to_nvram to prevent oops in compression code.
Date: Thu, 1 Dec 2011 13:26:22 +1100 [thread overview]
Message-ID: <20111201132622.2b23a1d7@kryten> (raw)
In-Reply-To: <1322705472.3729.11.camel@pasglop>
Hi Ben,
> How would we miss ?
>
> trylock does loop on stwcx. failure, it doesn't loop if the lock is
> -taken-, so if the lock is only used for actually dealing with the
> oops the only "miss" is because somebody already got it... or am I
> missing something ?
I'm thinking of two CPUs that enter at exactly the same time either
through a system reset or an ugly bug (writing junk at 0x900 so the
decrementer exception gets an oops). Probably unlikely enough that we
don't care.
Anton
next prev parent reply other threads:[~2011-12-01 2:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-01 1:46 [PATCH] powerpc/nvram: Add spinlock to oops_to_nvram to prevent oops in compression code Anton Blanchard
2011-12-01 2:11 ` Benjamin Herrenschmidt
2011-12-01 2:26 ` Anton Blanchard [this message]
2011-12-02 1:37 ` Jim Keniston
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=20111201132622.2b23a1d7@kryten \
--to=anton@samba.org \
--cc=benh@kernel.crashing.org \
--cc=jkenisto@us.ibm.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=paulus@samba.org \
/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).