From: Dave Hansen <dave@linux.vnet.ibm.com>
To: David Rientjes <rientjes@google.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Michael J Wolf <mjwolf@us.ibm.com>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [RFC][PATCH 2/6] pagewalk: only split huge pages when necessary
Date: Fri, 04 Feb 2011 09:19:12 -0800 [thread overview]
Message-ID: <1296839952.6737.2316.camel@nimitz> (raw)
In-Reply-To: <alpine.DEB.2.00.1102031343530.1307@chino.kir.corp.google.com>
On Thu, 2011-02-03 at 13:46 -0800, David Rientjes wrote:
> > Probably, but we don't currently have any central documentation for it.
> > Guess we could make some, or just ensure that all the users got updated.
> > Any ideas where to put it other than the mm_walk struct?
>
> I think noting it where struct mm_walk is declared would be best (just a
> "/* must handle pmd_trans_huge() */" would be sufficient) although
> eventually it might be cleaner to add a ->pmd_huge_entry().
For code maintenance, I really like _not_ hiding this in the API
somewhere. This way, we have a great, self-explanatory tag wherever
code (possibly) hasn't properly dealt with THPs. We get a nice,
greppable, cscope'able:
split_huge_page_pmd()
wherever we need to "teach" the code about THP.
It's kinda like the BKL. :)
-- Dave
WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: David Rientjes <rientjes@google.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Michael J Wolf <mjwolf@us.ibm.com>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [RFC][PATCH 2/6] pagewalk: only split huge pages when necessary
Date: Fri, 04 Feb 2011 09:19:12 -0800 [thread overview]
Message-ID: <1296839952.6737.2316.camel@nimitz> (raw)
In-Reply-To: <alpine.DEB.2.00.1102031343530.1307@chino.kir.corp.google.com>
On Thu, 2011-02-03 at 13:46 -0800, David Rientjes wrote:
> > Probably, but we don't currently have any central documentation for it.
> > Guess we could make some, or just ensure that all the users got updated.
> > Any ideas where to put it other than the mm_walk struct?
>
> I think noting it where struct mm_walk is declared would be best (just a
> "/* must handle pmd_trans_huge() */" would be sufficient) although
> eventually it might be cleaner to add a ->pmd_huge_entry().
For code maintenance, I really like _not_ hiding this in the API
somewhere. This way, we have a great, self-explanatory tag wherever
code (possibly) hasn't properly dealt with THPs. We get a nice,
greppable, cscope'able:
split_huge_page_pmd()
wherever we need to "teach" the code about THP.
It's kinda like the BKL. :)
-- Dave
--
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>
next prev parent reply other threads:[~2011-02-04 17:19 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-01 0:33 [RFC][PATCH 0/6] more detailed per-process transparent hugepage statistics Dave Hansen
2011-02-01 0:33 ` Dave Hansen
2011-02-01 0:33 ` [RFC][PATCH 1/6] count transparent hugepage splits Dave Hansen
2011-02-01 0:33 ` Dave Hansen
2011-02-01 9:58 ` Johannes Weiner
2011-02-01 9:58 ` Johannes Weiner
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:22 ` David Rientjes
2011-02-04 21:18 ` Andrea Arcangeli
2011-02-04 21:18 ` Andrea Arcangeli
2011-02-04 21:28 ` Dave Hansen
2011-02-04 21:28 ` Dave Hansen
2011-02-01 0:33 ` [RFC][PATCH 2/6] pagewalk: only split huge pages when necessary Dave Hansen
2011-02-01 0:33 ` Dave Hansen
2011-02-01 10:04 ` Johannes Weiner
2011-02-01 10:04 ` Johannes Weiner
2011-02-01 15:03 ` Dave Hansen
2011-02-01 15:03 ` Dave Hansen
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:33 ` Dave Hansen
2011-02-03 21:33 ` Dave Hansen
2011-02-03 21:46 ` David Rientjes
2011-02-03 21:46 ` David Rientjes
2011-02-04 17:19 ` Dave Hansen [this message]
2011-02-04 17:19 ` Dave Hansen
2011-02-04 21:10 ` Andrea Arcangeli
2011-02-04 21:10 ` Andrea Arcangeli
2011-02-01 0:34 ` [RFC][PATCH 3/6] break out smaps_pte_entry() from smaps_pte_range() Dave Hansen
2011-02-01 0:34 ` Dave Hansen
2011-02-01 10:08 ` Johannes Weiner
2011-02-01 10:08 ` Johannes Weiner
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:40 ` Dave Hansen
2011-02-03 21:40 ` Dave Hansen
2011-02-01 0:34 ` [RFC][PATCH 4/6] pass pte size argument in to smaps_pte_entry() Dave Hansen
2011-02-01 0:34 ` Dave Hansen
2011-02-01 10:09 ` Johannes Weiner
2011-02-01 10:09 ` Johannes Weiner
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:22 ` David Rientjes
2011-02-01 0:34 ` [RFC][PATCH 5/6] teach smaps_pte_range() about THP pmds Dave Hansen
2011-02-01 0:34 ` Dave Hansen
2011-02-01 10:11 ` Johannes Weiner
2011-02-01 10:11 ` Johannes Weiner
2011-02-01 15:02 ` Dave Hansen
2011-02-01 15:02 ` Dave Hansen
2011-02-01 16:09 ` Andrea Arcangeli
2011-02-01 16:09 ` Andrea Arcangeli
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:34 ` Dave Hansen
2011-02-03 21:34 ` Dave Hansen
2011-02-01 0:34 ` [RFC][PATCH 6/6] have smaps show transparent huge pages Dave Hansen
2011-02-01 0:34 ` Dave Hansen
2011-02-01 10:12 ` Johannes Weiner
2011-02-01 10:12 ` Johannes Weiner
2011-02-03 21:22 ` David Rientjes
2011-02-03 21:22 ` David Rientjes
2011-02-01 15:38 ` [RFC][PATCH 0/6] more detailed per-process transparent hugepage statistics Andrea Arcangeli
2011-02-01 15:38 ` Andrea Arcangeli
2011-02-01 17:15 ` Dave Hansen
2011-02-01 17:15 ` Dave Hansen
2011-02-01 20:39 ` Andrea Arcangeli
2011-02-01 20:39 ` Andrea Arcangeli
2011-02-01 20:56 ` Dave Hansen
2011-02-01 20:56 ` Dave Hansen
2011-02-02 0:07 ` Andrea Arcangeli
2011-02-02 0:07 ` Andrea Arcangeli
2011-02-08 17:54 ` Dave Hansen
2011-02-08 17:54 ` Dave Hansen
2011-02-08 18:17 ` Andrea Arcangeli
2011-02-08 18:17 ` Andrea Arcangeli
2011-02-03 21:54 ` David Rientjes
2011-02-03 21:54 ` David Rientjes
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=1296839952.6737.2316.camel@nimitz \
--to=dave@linux.vnet.ibm.com \
--cc=aarcange@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mjwolf@us.ibm.com \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.