From: Darren Hart <dvhart@linux.intel.com>
To: zhang.yi20@zte.com.cn
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Dave Hansen <dave@linux.vnet.ibm.com>
Subject: Re: [PATCH] futex: bugfix for futex-key conflict when futex use hugepage
Date: Wed, 17 Apr 2013 07:18:25 -0700 [thread overview]
Message-ID: <516EAF31.8000107@linux.intel.com> (raw)
In-Reply-To: <OF79A40956.94F46B9C-ON48257B50.00320F73-48257B50.0036925D@zte.com.cn>
On 04/17/2013 02:55 AM, zhang.yi20@zte.com.cn wrote:
> Darren Hart <dvhart@linux.intel.com> wrote on 2013/04/17 01:57:10:
>
>> Again, a functional testcase in futextest would be a good idea. This
>> helps validate the patch and also can be used to identify regressions in
>> the future.
>
> I will post the testcase code later.
>
>>
>> What is the max value of comp_idx? Are we at risk of truncating it?
>> Looks like not really from my initial look.
>>
>> This also needs a comment in futex.h describing the usage of the offset
>> field in union futex_key as well as above get_futex_key describing the
>> key for shared mappings.
>>
>>
>
> As far as I know , the max size of one hugepage is 1 GBytes for x86 cpu.
> Can some other cpus support greater hugepage even more than 4 GBytes? If
> so, we can change the type of 'offset' from int to long to avoid
> truncating.
I discussed this with Dave Hansen, on CC, and he thought we needed 9
bits, so even on x86 32b we should be covered.
--
Darren Hart
Intel Open Source Technology Center
Yocto Project - Technical Lead - Linux Kernel
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-04-17 14:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-16 3:37 [PATCH] futex: bugfix for futex-key conflict when futex use hugepage zhang.yi20
2013-04-16 17:57 ` Darren Hart
2013-04-17 9:55 ` zhang.yi20
2013-04-17 14:18 ` Darren Hart [this message]
2013-04-17 15:26 ` Dave Hansen
2013-04-17 15:51 ` Darren Hart
2013-04-18 8:05 ` zhang.yi20
2013-04-18 14:34 ` Darren Hart
2013-04-19 2:13 ` zhang.yi20
2013-04-19 2:42 ` Darren Hart
2013-04-19 2:45 ` Darren Hart
2013-04-19 7:03 ` zhang.yi20
2013-04-18 10:14 ` 答复: " zhang.yi20
2013-04-16 18:37 ` Dave Hansen
2013-04-16 18:47 ` Darren Hart
2013-04-17 7:25 ` 答复: " zhang.yi20
2013-04-17 7:47 ` zhang.yi20
-- strict thread matches above, loose matches on Subject: below --
2013-04-08 6:34 jiang.biao2
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=516EAF31.8000107@linux.intel.com \
--to=dvhart@linux.intel.com \
--cc=dave@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=zhang.yi20@zte.com.cn \
/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).