From: David Daney <ddaney@caviumnetworks.com>
To: David Miller <davem@davemloft.net>
Cc: rostedt@goodmis.org, linux-kernel@vger.kernel.org, mingo@elte.hu,
akpm@linux-foundation.org, fweisbec@gmail.com, jbaron@redhat.com
Subject: Re: [PATCH 4/8] jump label: Make arch_jump_label_text_poke_early() optional
Date: Fri, 29 Oct 2010 13:48:31 -0700 [thread overview]
Message-ID: <4CCB331F.6070507@caviumnetworks.com> (raw)
In-Reply-To: <20101029.133759.48489968.davem@davemloft.net>
On 10/29/2010 01:37 PM, David Miller wrote:
> From: Steven Rostedt<rostedt@goodmis.org>
> Date: Thu, 28 Oct 2010 09:55:52 -0400
>
>> From: David Daney<ddaney@caviumnetworks.com>
>>
>> For the forthcoming MIPS jump label support,
>> arch_jump_label_text_poke_early() is unneeded as the MIPS NOP
>> instruction is already optimal.
>>
>> Supply a default implementation that does nothing. Flag x86 and SPARC
>> as having arch_jump_label_text_poke_early().
>>
>> Cc: Jason Baron<jbaron@redhat.com>
>> Cc: David Miller<davem@davemloft.net>
>> Signed-off-by: David Daney<ddaney@caviumnetworks.com>
>> LKML-Reference:<1286218615-24011-2-git-send-email-ddaney@caviumnetworks.com>
>> Signed-off-by: Steven Rostedt<rostedt@goodmis.org>
>
> On the SPARC side, it's not that the nop isn't optimal, on sparc it's
> always 0x01000000.
That's what I thought. You could remove your
arch_jump_label_text_poke_early() function to no determent.
> The issue is that when written an I-cache flush is
> necessary using a 'flushi' instruction.
>
> Does MIPS not need a flush when poking instructions?
Yes, it does.
> I find this hard to believe, although it's been some time since I
> last touched that architecture :-)
I just looked at my patch again. I am indeed flushing the I cache
after patching the code, so I don't really know what you are talking
about.
David Daney
next prev parent reply other threads:[~2010-10-29 20:48 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-28 13:55 [PATCH 0/8] [GIT PULL] jump label: various fixes and updates Steven Rostedt
2010-10-28 13:55 ` [PATCH 1/8] jump label: Fix module __init section race Steven Rostedt
2010-10-28 13:55 ` [PATCH 2/8] jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex Steven Rostedt
2010-10-28 13:55 ` [PATCH 3/8] jump label: Fix error with preempt disable holding mutex Steven Rostedt
2010-10-29 4:20 ` Masami Hiramatsu
2010-10-28 13:55 ` [PATCH 4/8] jump label: Make arch_jump_label_text_poke_early() optional Steven Rostedt
2010-10-29 20:37 ` David Miller
2010-10-29 20:48 ` David Daney [this message]
2010-10-28 13:55 ` [PATCH 5/8] jump label: Add MIPS support Steven Rostedt
2010-10-28 13:55 ` [PATCH 6/8] jump_label: Fix unaligned traps on sparc Steven Rostedt
2010-10-28 13:55 ` [PATCH 7/8] x86, ftrace: Use safe noops, drop trap test Steven Rostedt
2010-10-28 13:55 ` [PATCH 8/8] jump label: Disable due to compiler bug Steven Rostedt
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=4CCB331F.6070507@caviumnetworks.com \
--to=ddaney@caviumnetworks.com \
--cc=akpm@linux-foundation.org \
--cc=davem@davemloft.net \
--cc=fweisbec@gmail.com \
--cc=jbaron@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=rostedt@goodmis.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