From: Andreas Schwab <schwab@linux-m68k.org>
To: Anton Blanchard <anton@samba.org>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [patch 1/3] powerpc: Move 64bit VDSO to improve context switch performance
Date: Sat, 03 Oct 2009 16:15:38 +0200 [thread overview]
Message-ID: <m28wfsef79.fsf@igel.home> (raw)
In-Reply-To: <m2ocophale.fsf__34527.2158309401$1254511503$gmane$org@igel.home> (Andreas Schwab's message of "Fri, 02 Oct 2009 21:14:37 +0200")
Andreas Schwab <schwab@linux-m68k.org> writes:
> Anton Blanchard <anton@samba.org> writes:
>
>> On 64bit applications the VDSO is the only thing in segment 0. Since the VDSO
>> is position independent we can remove the hint and let get_unmapped_area pick
>> an area.
>
> This breaks gdb. The section table in the VDSO image when mapped into
> the process no longer contains meaningful values, and gdb rejects it.
The problem is that the load segment requires 64k alignment, but the
page allocater of course only provides PAGE_SIZE alignment, causing the
image to be unaligned in memory.
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
next prev parent reply other threads:[~2009-10-03 14:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-14 6:53 [patch 0/3] PowerPC context switch optimisations Anton Blanchard
2009-07-14 6:53 ` [patch 1/3] powerpc: Move 64bit VDSO to improve context switch performance Anton Blanchard
2009-07-14 7:07 ` Benjamin Herrenschmidt
2009-07-14 7:38 ` Anton Blanchard
2009-10-02 19:14 ` Andreas Schwab
[not found] ` <m2ocophale.fsf__34527.2158309401$1254511503$gmane$org@igel.home>
2009-10-03 14:15 ` Andreas Schwab [this message]
2009-10-03 14:51 ` Andreas Schwab
2009-10-03 21:53 ` Benjamin Herrenschmidt
2009-10-04 12:35 ` Andreas Schwab
2009-07-14 6:53 ` [patch 2/3] powerpc: Rearrange SLB preload code Anton Blanchard
2009-07-14 6:53 ` [patch 3/3] powerpc: Preload application text segment instead of TASK_UNMAPPED_BASE Anton Blanchard
2009-07-14 7:10 ` Benjamin Herrenschmidt
2009-07-14 7:27 ` Anton Blanchard
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=m28wfsef79.fsf@igel.home \
--to=schwab@linux-m68k.org \
--cc=anton@samba.org \
--cc=linuxppc-dev@ozlabs.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 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).