From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>,
linuxppc-dev <linuxppc-dev@ozlabs.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: Re: powernv: Avoid calling trace tlbie in kexec path.
Date: Fri, 24 Nov 2017 20:46:40 +1100 (AEDT) [thread overview]
Message-ID: <3yjrtm43yYz9sRn@ozlabs.org> (raw)
In-Reply-To: <151137178794.14123.18003389448303728066.stgit@jupiter.in.ibm.com>
On Wed, 2017-11-22 at 17:32:07 UTC, Mahesh J Salgaonkar wrote:
> From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
>
> Rebooting into a new kernel with kexec fails in trace_tlbie() which is
> called from native_hpte_clear(). This happens if the running kernel has
> CONFIG_LOCKDEP enabled. With lockdep enabled, the tracepoints always
> execute few RCU checks regardless of whether tracing is on or off.
> We are already in the last phase of kexec sequence in real mode with
> HILE_BE set. At this point the RCU check ends up in RCU_LOCKDEP_WARN and
> causes kexec to fail.
>
> Fix this by not calling trace_tlbie() from native_hpte_clear().
>
> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/a3961f824cdbe7eb431254dc7d8f6f
cheers
prev parent reply other threads:[~2017-11-24 9:46 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-22 17:32 [PATCH] powernv: Avoid calling trace tlbie in kexec path Mahesh J Salgaonkar
2017-11-22 19:07 ` Naveen N. Rao
2017-11-23 9:38 ` Mahesh Jagannath Salgaonkar
2017-11-23 10:02 ` Naveen N. Rao
2017-11-22 22:56 ` Balbir Singh
2017-11-23 11:18 ` Mahesh Jagannath Salgaonkar
2017-11-23 12:15 ` Michael Ellerman
2017-11-23 13:11 ` Naveen N. Rao
2017-11-24 4:13 ` Balbir Singh
2017-11-24 6:10 ` Michael Ellerman
2017-11-24 6:10 ` Michael Ellerman
2017-11-24 9:46 ` Michael Ellerman [this message]
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=3yjrtm43yYz9sRn@ozlabs.org \
--to=patch-notifications@ellerman.id.au \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=linuxppc-dev@ozlabs.org \
--cc=mahesh@linux.vnet.ibm.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).