From: Rui Teng <rui.teng@linux.vnet.ibm.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Chen Gang <chengang@emindsoft.com.cn>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Vlastimil Babka <vbabka@suse.cz>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>,
hejianet@linux.vnet.ibm.com
Subject: Re: [RFC] mm: Change the data type of huge page size from unsigned long to u64
Date: Tue, 13 Sep 2016 19:21:07 +0800 [thread overview]
Message-ID: <09ab7941-07fa-0003-46d8-9fa5c07eba2d@linux.vnet.ibm.com> (raw)
In-Reply-To: <20160913093257.GA31186@node>
On 9/13/16 5:32 PM, Kirill A. Shutemov wrote:
> On Tue, Sep 13, 2016 at 05:26:05PM +0800, Rui Teng wrote:
>> The huge page size could be 16G(0x400000000) on ppc64 architecture, and it will
>> cause an overflow on unsigned long data type(0xFFFFFFFF).
>
> Huh? ppc64 is 64-bit system and sizeof(void *) is equal to
> sizeof(unsigned long) on Linux (LP64 model).
>
> So where your 0xFFFFFFFF comes from?
>
The size of unsigned long data type is 4 bytes, and the 0xFFFFFFFF here
is the maximum value. And 16G is bigger than it.
--
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:[~2016-09-13 11:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-13 9:26 Rui Teng
2016-09-13 9:32 ` Kirill A. Shutemov
2016-09-13 11:21 ` Rui Teng [this message]
2016-09-13 11:40 ` Kirill A. Shutemov
2016-09-13 13:08 ` Rui Teng
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=09ab7941-07fa-0003-46d8-9fa5c07eba2d@linux.vnet.ibm.com \
--to=rui.teng@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=chengang@emindsoft.com.cn \
--cc=hejianet@linux.vnet.ibm.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kirill@shutemov.name \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=n-horiguchi@ah.jp.nec.com \
--cc=vbabka@suse.cz \
/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