From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Kent Overstreet <kmo@daterainc.com>
Cc: Ben Hutchings <ben@decadent.org.uk>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org
Subject: Re: PREEMPT_RT vs bcache
Date: Wed, 7 Aug 2013 23:12:37 +0200 [thread overview]
Message-ID: <20130807211237.GM6104@pengutronix.de> (raw)
In-Reply-To: <20130807205357.GD11612@kmo-pixel>
On Wed, Aug 07, 2013 at 01:53:57PM -0700, Kent Overstreet wrote:
> On Wed, Aug 07, 2013 at 10:28:18PM +0200, Ben Hutchings wrote:
> > As Kent said back in 2011 (commit 84759c6d18c5), bcache needs
> > {down,up}_read_non_owner(). But these are not implemented by the -rt
> > patchset when PREEMPT_RT_FULL is enabled. Can they be added, or is
> > there a fundamental conflict here?
>
> You should be able to cherry pick
> 84759c6d18c5144432781ddca037d929ee9db8a5 (Revert "rw_semaphore: remove
> up/down_read_non_owner") - that went in when bcache was merged.
That doesn't help with PREEMPT_RT_FULL because include/linux/rwsem.h
looks like:
[ ... some includes ... ]
#ifdef CONFIG_PREEMPT_RT_FULL
#include <linux/rwsem_rt.h>
#else /* PREEMPT_RT_FULL */
[ ... vanilla content including definitions of {down,up}_read_non_owner]
#endif
So Ben's question was how (if at all) we should implement
{down,up}_read_non_owner for PREEMPT_RT_FULL.
Is it save to just use the vanilla implementation on RT?
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
next prev parent reply other threads:[~2013-08-07 21:12 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-07 20:28 PREEMPT_RT vs bcache Ben Hutchings
2013-08-07 20:53 ` Kent Overstreet
2013-08-07 21:08 ` Ben Hutchings
2013-08-07 21:09 ` Kent Overstreet
2013-08-07 21:12 ` Uwe Kleine-König [this message]
2013-08-08 7:26 ` Christoph Hellwig
2013-08-08 7:43 ` Kent Overstreet
2013-08-08 12:11 ` Christoph Hellwig
2013-09-12 15:01 ` Thomas Gleixner
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=20130807211237.GM6104@pengutronix.de \
--to=u.kleine-koenig@pengutronix.de \
--cc=ben@decadent.org.uk \
--cc=kmo@daterainc.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tglx@linutronix.de \
/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.