From: Ingo Molnar <mingo@elte.hu>
To: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf_counter: powerpc: add nmi_enter/nmi_exit calls
Date: Thu, 9 Apr 2009 07:20:02 +0200 [thread overview]
Message-ID: <20090409052002.GE5352@elte.hu> (raw)
In-Reply-To: <18909.31952.873098.336615@cargo.ozlabs.ibm.com>
* Paul Mackerras <paulus@samba.org> wrote:
> Impact: powerpc bug fix
>
> Now that the core is using in_nmi() (added in e30e08f6,
> "perf_counter: fix NMI race in task clock"), we need the powerpc
> perf_counter_interrupt to call nmi_enter() and nmi_exit() in those
> cases where the interrupt happens when interrupts are
> soft-disabled. If interrupts were soft-enabled, we can treat it
> as a regular interrupt and do irq_enter/irq_exit around the whole
> routine. This lets us get rid of the test_perf_counter_pending()
> call at the end of perf_counter_interrupt, thus simplifying things
> a little.
applied, thanks Paul!
I'm wondering, what was the real impact? Was it a crash or some
other misbehavior? This impact line:
Impact: powerpc bug fix
is a bit too generic to be useful in practice. Something like:
Impact: fix stuck NMIs on powerpc
Impact: fix NMI crash on powerpc
would have been more descriptive about the real, hands-on impact of
this patch.
Ingo
next prev parent reply other threads:[~2009-04-09 5:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-09 4:42 [PATCH] perf_counter: powerpc: add nmi_enter/nmi_exit calls Paul Mackerras
2009-04-09 5:20 ` Ingo Molnar [this message]
2009-04-09 5:49 ` Paul Mackerras
2009-04-09 6:05 ` Ingo Molnar
2009-04-09 5:30 ` [tip:perfcounters/core] " Paul Mackerras
2009-04-09 5:57 ` Paul Mackerras
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=20090409052002.GE5352@elte.hu \
--to=mingo@elte.hu \
--cc=a.p.zijlstra@chello.nl \
--cc=linux-kernel@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.