LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Adam Litke <agl@us.ibm.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/7] [RFC] hugetlb: pagetable_operations API
Date: Wed, 21 Feb 2007 06:54:57 +1100	[thread overview]
Message-ID: <1172001297.18571.130.camel@localhost.localdomain> (raw)
In-Reply-To: <1171910581.3531.89.camel@laptopd505.fenrus.org>

On Mon, 2007-02-19 at 19:43 +0100, Arjan van de Ven wrote:
> On Mon, 2007-02-19 at 10:31 -0800, Adam Litke wrote:
> > The page tables for hugetlb mappings are handled differently than page tables
> > for normal pages.  Rather than integrating multiple page size support into the
> > main VM (which would tremendously complicate the code) some hooks were created.
> > This allows hugetlb special cases to be handled "out of line" by a separate
> > interface.
> 
> ok it makes sense to clean this up.. what I don't like is that there
> STILL are all the double cases... for this to work and be worth it both
> the common case and the hugetlb case should be using the ops structure
> always! Anything else and you're just replacing bad code with bad
> code ;(

I don't fully agree. I think it makes sense to have the "special" case
be a function pointer and the "normal" case stay where it is for
performances. You don't want to pay the cost of the function pointer
call in the normal case do you ?

Ben.



      parent reply	other threads:[~2007-02-20 19:56 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-19 18:31 Adam Litke
2007-02-19 18:31 ` [PATCH 1/7] Introduce the pagetable_operations and associated helper macros Adam Litke
2007-02-19 18:41   ` Arjan van de Ven
2007-02-19 19:31     ` Adam Litke
2007-02-19 19:48   ` William Lee Irwin III
2007-02-19 22:29   ` Christoph Hellwig
2007-02-20 15:50     ` Mel Gorman
2007-02-19 18:31 ` [PATCH 2/7] copy_vma for hugetlbfs Adam Litke
2007-02-19 18:31 ` [PATCH 3/7] pin_pages for hugetlb Adam Litke
2007-02-19 18:32 ` [PATCH 4/7] unmap_page_range " Adam Litke
2007-02-19 18:32 ` [PATCH 5/7] change_protection " Adam Litke
2007-02-19 18:32 ` [PATCH 6/7] free_pgtable_range " Adam Litke
2007-02-19 18:32 ` [PATCH 7/7] hugetlbfs fault handler Adam Litke
2007-02-19 18:43 ` [PATCH 0/7] [RFC] hugetlb: pagetable_operations API Arjan van de Ven
2007-02-19 19:34   ` Adam Litke
2007-02-19 21:15     ` Arjan van de Ven
2007-02-20 19:57       ` Benjamin Herrenschmidt
2007-02-20 19:54   ` Benjamin Herrenschmidt [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=1172001297.18571.130.camel@localhost.localdomain \
    --to=benh@kernel.crashing.org \
    --cc=agl@us.ibm.com \
    --cc=arjan@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --subject='Re: [PATCH 0/7] [RFC] hugetlb: pagetable_operations API' \
    /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

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).