From: "H. Peter Anvin" <hpa@zytor.com>
To: stefani@seibold.net, gregkh@linuxfoundation.org,
linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de,
mingo@redhat.com, ak@linux.intel.com, aarcange@redhat.com,
john.stultz@linaro.org, luto@amacapital.net, xemul@parallels.com,
gorcunov@openvz.org, andriy.shevchenko@linux.intel.com
Cc: Martin.Runge@rohde-schwarz.com, Andreas.Brief@rohde-schwarz.com
Subject: Re: [PATCH 4/4] Add 32 bit VDSO time support for 64 bit kernel
Date: Sat, 01 Feb 2014 12:29:01 -0800 [thread overview]
Message-ID: <52ED590D.8090208@zytor.com> (raw)
In-Reply-To: <1391268756-10766-5-git-send-email-stefani@seibold.net>
On 02/01/2014 07:32 AM, stefani@seibold.net wrote:
>
> This kind of type hacking could be prevent in the future by doing a call to the
> 64 bit code by the following sequence:
>
> - Compile the arch/x86/vdso/vclock_gettime.c as 64 bit, but only generate
> the assembler output.
> - Next compile a 32 bit object by including the 64 bit vclock_gettime.s
> prefixed with .code64
> - At least we need a trampolin code which invokes the 64 bit code and do
> the API conversation (64 bit longs to 32 bit longs), like the
> followig snipped:
>
Honestly, I think the overhead of the mode switch would ruin a lot of
the advantages with the vdso.
-hpa
prev parent reply other threads:[~2014-02-01 20:29 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-01 15:32 [PATCH 0/4] Add 32 bit VDSO time function support stefani
2014-02-01 15:32 ` [PATCH 1/4] Make vsyscall_gtod_data handling x86 generic stefani
2014-02-01 23:40 ` Andy Lutomirski
2014-02-01 15:32 ` [PATCH 2/4] Add new func _install_special_mapping() to mmap.c stefani
2014-02-01 15:32 ` [PATCH 3/4] Add 32 bit VDSO time support for 32 bit kernel stefani
2014-02-01 23:59 ` Andy Lutomirski
2014-02-02 0:26 ` H. Peter Anvin
2014-02-02 0:30 ` Andy Lutomirski
2014-02-02 0:41 ` H. Peter Anvin
2014-02-02 0:56 ` H. Peter Anvin
2014-02-03 21:11 ` Roland McGrath
2014-02-02 11:20 ` Stefani Seibold
2014-02-02 15:25 ` H. Peter Anvin
2014-02-01 15:32 ` [PATCH 4/4] Add 32 bit VDSO time support for 64 " stefani
2014-02-01 20:29 ` H. Peter Anvin [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=52ED590D.8090208@zytor.com \
--to=hpa@zytor.com \
--cc=Andreas.Brief@rohde-schwarz.com \
--cc=Martin.Runge@rohde-schwarz.com \
--cc=aarcange@redhat.com \
--cc=ak@linux.intel.com \
--cc=andriy.shevchenko@linux.intel.com \
--cc=gorcunov@openvz.org \
--cc=gregkh@linuxfoundation.org \
--cc=john.stultz@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=mingo@redhat.com \
--cc=stefani@seibold.net \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--cc=xemul@parallels.com \
/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.