linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: David Miller <davem@davemloft.net>
Cc: rientjes@google.com, ian.campbell@citrix.com,
	linux-kernel@vger.kernel.org, hch@infradead.org,
	jaxboe@fusionio.com, linux-mm@kvack.org
Subject: Re: [PATCH] mm: add a "struct page_frag" type containing a page, offset and length
Date: Thu, 13 Oct 2011 14:22:01 -0700	[thread overview]
Message-ID: <20111013142201.355f9afc.akpm@linux-foundation.org> (raw)
In-Reply-To: <20111013.165148.64222593458932960.davem@davemloft.net>

On Thu, 13 Oct 2011 16:51:48 -0400 (EDT)
David Miller <davem@davemloft.net> wrote:

> >> 
> >> http://patchwork.ozlabs.org/patch/118693/
> >> http://patchwork.ozlabs.org/patch/118694/
> >> http://patchwork.ozlabs.org/patch/118695/
> >> http://patchwork.ozlabs.org/patch/118700/
> >> http://patchwork.ozlabs.org/patch/118696/
> >> http://patchwork.ozlabs.org/patch/118699/
> >> 
> >> This is a replacement for patch #1 in that series.
> >> 
> > 
> > Ok, let's add Andrew to the thread so this can go through -mm in 
> > preparation for that series.
> 
> It doesn't usually work like that, net-next is usually one of the first
> trees that Stephen pulls into -next, so this kind of simple dependency should
> go into my tree

yup.

> if the -mm developers give it an ACK and are OK with it.

Looks OK to me.  I'm surprised we don't already have such a thing.

Review comments:


> +struct page_frag {
> +	struct page *page;
> +#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)

It does add risk that people will add compile warnings and bugs by
failing to consider or test the other case.

We could reduce that risk by doing

   #if (PAGE_SIZE >= 65536)

but then the 32-bit version would hardly ever be tested at all.

> +	__u32 page_offset;

I suggest this be called simply "offset".

> +	__u32 size;
> +#else
> +	__u16 page_offset;
> +	__u16 size;
> +#endif
> +};
> 	
> 

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2011-10-13 21:22 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-13 10:02 [PATCH] mm: add a "struct page_frag" type containing a page, offset and length Ian Campbell
2011-10-13 20:33 ` David Rientjes
2011-10-13 20:37   ` David Miller
2011-10-13 20:49     ` David Rientjes
2011-10-13 20:51       ` David Miller
2011-10-13 21:22         ` Andrew Morton [this message]
2011-10-14  6:56           ` Ian Campbell
2011-10-18  8:49             ` Ian Campbell
2011-10-20  5:36               ` David Rientjes
2011-10-20  5:44                 ` Andrew Morton
2011-10-20  8:59               ` David Miller
2011-10-20  9:04                 ` Ian Campbell
2011-10-14  6:42 ` Jens Axboe
2011-10-14  9:17   ` David Rientjes
2011-10-14  9:54     ` Jens Axboe

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=20111013142201.355f9afc.akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=davem@davemloft.net \
    --cc=hch@infradead.org \
    --cc=ian.campbell@citrix.com \
    --cc=jaxboe@fusionio.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=rientjes@google.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).