linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Chris Wright <chrisw@sous-sol.org>
To: Avi Kivity <avi@qumranet.com>
Cc: Chris Wright <chrisw@sous-sol.org>,
	Izik Eidus <izike@qumranet.com>,
	andrea@qumranet.com, yaniv@qumranet.com,
	kvm-devel <kvm-devel@lists.sourceforge.net>,
	linux-mm@kvack.org
Subject: Re: [kvm-devel] [RFC][PATCH 3/5] ksm source code
Date: Thu, 24 Jan 2008 12:34:52 -0800	[thread overview]
Message-ID: <20080124203452.GB3627@sequoia.sous-sol.org> (raw)
In-Reply-To: <4798E9D2.8030503@qumranet.com>

* Avi Kivity (avi@qumranet.com) wrote:
> Chris Wright wrote:
>>>>  struct ksm_memory_region {
>>>>  	__u32 npages; /* number of pages to share */
>>>>  	__u64 addr; /* the begining of the virtual address */
>>>>  };
>>>>       
>>> why isnt it compat safe?
>>
>> 32-bit has more relaxed alignment requirement for __u64 (4 bytes)
>> than 64-bit (8 bytes).  choices are reverse the order or add padding
>> (can test by compiling structure in 32 and 64 bit).
>
> Reversing the order isn't good enough, since the structure size would be 
> different, and that is embedded in the ioctl number.

good point.

> Padding is necessary.
>
> [wishlist: struct { ... } __attribute__((abi_x86_64));]

--
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>

      reply	other threads:[~2008-01-24 20:34 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-21 16:12 Izik Eidus
2008-01-24  7:24 ` [kvm-devel] " Chris Wright
2008-01-24  9:07   ` Izik Eidus
2008-01-24  9:22     ` Avi Kivity
2008-01-24  9:48       ` Izik Eidus
2008-01-24 17:53       ` Chris Wright
2008-01-24 17:51     ` Chris Wright
2008-01-24 19:41       ` Avi Kivity
2008-01-24 20:34         ` Chris Wright [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=20080124203452.GB3627@sequoia.sous-sol.org \
    --to=chrisw@sous-sol.org \
    --cc=andrea@qumranet.com \
    --cc=avi@qumranet.com \
    --cc=izike@qumranet.com \
    --cc=kvm-devel@lists.sourceforge.net \
    --cc=linux-mm@kvack.org \
    --cc=yaniv@qumranet.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