From: Tejun Heo <tj@kernel.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>,
Christoph Lameter <cl@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"rusty@rustcorp.com.au" <rusty@rustcorp.com.au>,
"mingo@redhat.com" <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"rostedt@goodmis.org" <rostedt@goodmis.org>,
"cebbert@redhat.com" <cebbert@redhat.com>
Subject: Re: [PATCH 13/16] percpu: remove per_cpu__ prefix.
Date: Thu, 15 Oct 2009 17:57:16 +0900 [thread overview]
Message-ID: <4AD6E3EC.8080901@kernel.org> (raw)
In-Reply-To: <4AD60C78.1090908@zytor.com>
Hello,
H. Peter Anvin wrote:
> Okay... I also don't seem to understand the more fundamental issue here,
> which is:
>
> Why are we dropping the prefix?
>
> It may be "insufficient", but at least it stands out like a sore thumb
> and makes mistakes harder. It would be a different thing if we could
> actually use the TLS ABI, but we really can't.
The reason for actively removing the prefix is because it forces us to
have two different accessors for static and dynamic ones which is made
worse by any accessor which will accept dynamic ones will accept
anything (static ones enclosed by per_cpu_var(), dynamic ones, plain
wrong random value). Also, wide spread use of per_cpu_var() in
generic code will basically circumvent any meaningful protection the
prefix provided.
Thanks.
--
tejun
next prev parent reply other threads:[~2009-10-15 8:58 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-14 6:01 [RFC percpu#for-next] percpu: drop per_cpu__ prefix and add sparse annotations, take#2 Tejun Heo
2009-10-14 6:01 ` [PATCH 01/16] vmalloc: fix use of non-existent percpu variable in put_cpu_var() Tejun Heo
2009-10-14 15:06 ` Christoph Lameter
2009-10-15 9:10 ` Tejun Heo
2009-10-14 6:01 ` [PATCH 02/16] percpu: make alloc_percpu() handle array types Tejun Heo
2009-10-14 6:01 ` [PATCH 03/16] percpu: remove some sparse warnings Tejun Heo
2009-10-14 14:20 ` Christoph Lameter
2009-10-14 6:01 ` [PATCH 04/16] percpu: make percpu symbols under kernel/ and mm/ unique Tejun Heo
2009-10-14 6:01 ` [PATCH 05/16] percpu: make percpu symbols in tracer unique Tejun Heo
2009-10-14 6:01 ` [PATCH 06/16] percpu: make percpu symbols in oprofile unique Tejun Heo
2009-10-14 6:01 ` [PATCH 07/16] percpu: make percpu symbols in cpufreq unique Tejun Heo
2009-10-14 6:01 ` [PATCH 08/16] percpu: make percpu symbols in xen unique Tejun Heo
2009-10-14 6:01 ` [PATCH 09/16] percpu: make percpu symbols in x86 unique Tejun Heo
2009-10-14 6:01 ` [PATCH 10/16] percpu: make percpu symbols in powerpc unique Tejun Heo
2009-10-27 3:19 ` Benjamin Herrenschmidt
2009-10-14 6:02 ` [PATCH 11/16] percpu: make percpu symbols in ia64 unique Tejun Heo
2009-10-14 6:02 ` [PATCH 12/16] percpu: make misc percpu symbols unique Tejun Heo
2009-10-14 6:02 ` [PATCH 13/16] percpu: remove per_cpu__ prefix Tejun Heo
2009-10-14 14:36 ` Christoph Lameter
2009-10-14 16:42 ` Luck, Tony
2009-10-14 17:38 ` H. Peter Anvin
2009-10-14 18:26 ` Christoph Lameter
2009-10-15 8:57 ` Tejun Heo [this message]
2009-10-14 18:22 ` Christoph Lameter
2009-10-14 18:36 ` Luck, Tony
2009-10-14 18:51 ` Christoph Lameter
2009-10-15 8:51 ` Tejun Heo
2009-10-16 16:23 ` Christoph Lameter
2009-10-15 9:24 ` Tejun Heo
2009-10-16 6:04 ` Michal Simek
2009-10-18 2:58 ` Tejun Heo
2009-10-19 13:41 ` Michal Simek
2009-10-29 11:11 ` Tejun Heo
2009-11-02 16:35 ` Michal Simek
2009-10-19 13:40 ` Michal Simek
2009-10-29 12:06 ` Tejun Heo
2009-10-14 6:02 ` [PATCH 14/16] percpu: make access macros universal Tejun Heo
2009-10-14 14:38 ` Christoph Lameter
2009-10-15 9:27 ` Tejun Heo
2009-10-14 6:02 ` [PATCH 15/16] percpu: add __percpu for sparse Tejun Heo
2009-10-14 6:02 ` [PATCH 16/16] percpu: make accessors check for percpu pointer in sparse Tejun Heo
2009-10-14 14:41 ` Christoph Lameter
2009-10-15 9:08 ` Tejun Heo
2009-10-29 13:40 ` [RFC percpu#for-next] percpu: drop per_cpu__ prefix and add sparse annotations, take#2 Tejun Heo
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=4AD6E3EC.8080901@kernel.org \
--to=tj@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=cebbert@redhat.com \
--cc=cl@linux-foundation.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=rostedt@goodmis.org \
--cc=rusty@rustcorp.com.au \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.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 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).