From: Sam Ravnborg <sam@ravnborg.org>
To: Helge Deller <deller@gmx.de>
Cc: Tim Abbott <tabbott@MIT.EDU>,
Linux kernel mailing list <linux-kernel@vger.kernel.org>,
Anders Kaseorg <andersk@MIT.EDU>, Waseem Daher <wdaher@MIT.EDU>,
Denys Vlasenko <vda.linux@googlemail.com>,
Jeff Arnold <jbarnold@MIT.EDU>, Kyle McMartin <kyle@mcmartin.ca>,
linux-parisc@vger.kernel.org
Subject: Re: [PATCH 3/5] parisc: use new macros for .data.init_task.
Date: Sun, 3 May 2009 00:10:06 +0200 [thread overview]
Message-ID: <20090502221006.GA4309@uranus.ravnborg.org> (raw)
In-Reply-To: <49FBD681.9080605@gmx.de>
On Sat, May 02, 2009 at 07:13:37AM +0200, Helge Deller wrote:
> Tim Abbott wrote:
> > .data.init_task should not need a separate output section; this change
> > moves it into the .data section.
> >
> > Signed-off-by: Tim Abbott <tabbott@mit.edu>
> > Cc: Kyle McMartin <kyle@mcmartin.ca>
> > Cc: Helge Deller <deller@gmx.de>
> > Cc: linux-parisc@vger.kernel.org
>
>
> I think this patch is wrong, although it is theoretically correct.
>
> IIRC, gcc on hppa is not able to provide an alignment >= 8k, which is
> why we have done the 16k alignment inside the linker script.
> So, I think this change will prevent the parisc kernel to boot up.
> Needs testing.
The patch does not do much...
>
> Helge
>
> > ---
> > arch/parisc/kernel/init_task.c | 2 +-
> > arch/parisc/kernel/vmlinux.lds.S | 10 ++--------
> > 2 files changed, 3 insertions(+), 9 deletions(-)
> >
> > diff --git a/arch/parisc/kernel/init_task.c b/arch/parisc/kernel/init_task.c
> > index 1e25a45..8ee17ea 100644
> > --- a/arch/parisc/kernel/init_task.c
> > +++ b/arch/parisc/kernel/init_task.c
> > @@ -48,7 +48,7 @@ EXPORT_SYMBOL(init_mm);
> > * "init_task" linker map entry..
> > */
> > union thread_union init_thread_union
> > - __attribute__((aligned(128))) __attribute__((__section__(".data.init_task"))) =
> > + __attribute__((aligned(128))) __init_task_data =
> > { INIT_THREAD_INFO(init_task) };
This is a simple replacement with a nicer way to say "this belongs to
the .data.init_task section - no functional difference.
> >
> > #if PT_NLEVELS == 3
> > diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
> > index b5936c9..c8a528d 100644
> > --- a/arch/parisc/kernel/vmlinux.lds.S
> > +++ b/arch/parisc/kernel/vmlinux.lds.S
> > @@ -103,6 +103,8 @@ SECTIONS
> > . = ALIGN(L1_CACHE_BYTES);
> > /* Data */
> > .data : {
> > + /* assembler code expects init_task to be 16k aligned */
> > + INIT_TASK_DATA(16384)
> > NOSAVE_DATA
> > CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
> > DATA_DATA
> > @@ -133,14 +135,6 @@ SECTIONS
> > }
> > __bss_stop = .;
> >
> > -
> > - /* assembler code expects init_task to be 16k aligned */
> > - . = ALIGN(16384);
> > - /* init_task */
> > - .data.init_task : {
> > - *(.data.init_task)
> > - }
> > -
This part moves away from a specific output section to including this in the
.data output section - with the _same_ alignmnet.
So the only issue here is that we move init_task before NOSAVE_DATA etc.
I do not see why you think this changes alignmnet?
Sam
next prev parent reply other threads:[~2009-05-02 22:08 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-30 23:55 [PATCH 0/5] section name cleanup for parisc Tim Abbott
2009-04-30 23:55 ` [PATCH 1/5] parisc: use NOSAVE_DATA macro for .data.nosave section Tim Abbott
2009-04-30 23:55 ` [PATCH 2/5] parisc: use new macro for .data.cacheline_aligned section Tim Abbott
2009-04-30 23:55 ` [PATCH 3/5] parisc: use new macros for .data.init_task Tim Abbott
2009-04-30 23:55 ` [PATCH 4/5] parisc: use new macro for .data.read_mostly section Tim Abbott
2009-04-30 23:55 ` [PATCH 5/5] parisc: convert to new generic read_mostly support Tim Abbott
2009-05-02 5:13 ` [PATCH 3/5] parisc: use new macros for .data.init_task Helge Deller
2009-05-02 14:04 ` John David Anglin
2009-05-02 14:13 ` Kyle McMartin
2009-05-02 16:16 ` Helge Deller
2009-05-02 16:52 ` John David Anglin
2009-05-02 22:10 ` Sam Ravnborg [this message]
2009-05-03 19:37 ` Helge Deller
2009-05-02 14:19 ` [PATCH 0/5] section name cleanup for parisc Kyle McMartin
2009-05-02 16:32 ` Sam Ravnborg
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=20090502221006.GA4309@uranus.ravnborg.org \
--to=sam@ravnborg.org \
--cc=andersk@MIT.EDU \
--cc=deller@gmx.de \
--cc=jbarnold@MIT.EDU \
--cc=kyle@mcmartin.ca \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-parisc@vger.kernel.org \
--cc=tabbott@MIT.EDU \
--cc=vda.linux@googlemail.com \
--cc=wdaher@MIT.EDU \
/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