From: Ralf Baechle <ralf@linux-mips.org>
To: Thomas Petazzoni <thomas.petazzoni@enix.org>
Cc: linux-mips@linux-mips.org, mentre@tcl.ite.mee.com
Subject: Re: Compilation fails with CONFIG_DEBUG_SPINLOCK
Date: Fri, 22 Oct 2004 14:50:19 +0200 [thread overview]
Message-ID: <20041022125019.GA642@linux-mips.org> (raw)
In-Reply-To: <20041013092057.GQ11236@enix.org>
On Wed, Oct 13, 2004 at 11:20:57AM +0200, Thomas Petazzoni wrote:
> I think this is trivial to fix, but I'm not sure what is the right
> place to declare the spin lock and to initialize it.
atomic_lock is intentionally undefined. The code using it should ever
be referenced on uni-processor systems that don't have ll/sc and on those
the spinlock code happens to not reference the spinlock_t argument not
at all. So iow if the compiled code actually references atomic_lock,
something is smelling. In general the reason is not having an
include/asm-mips/mach-<foo>/cpu-feature-overrides.h file. If this is
missing the kernel will fallback to runtime detection of cpu_has_llsc
which due to the performance sensitive nature of most atomic_t users is
a bad idea. So this error is the bomb hidden in the code to alert
users ...
Ralf
prev parent reply other threads:[~2004-10-22 12:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-13 9:20 Compilation fails with CONFIG_DEBUG_SPINLOCK Thomas Petazzoni
2004-10-18 10:03 ` Thomas Petazzoni
2004-10-22 12:50 ` Ralf Baechle [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=20041022125019.GA642@linux-mips.org \
--to=ralf@linux-mips.org \
--cc=linux-mips@linux-mips.org \
--cc=mentre@tcl.ite.mee.com \
--cc=thomas.petazzoni@enix.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.