linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Minchan Kim <minchan@kernel.org>
To: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Ralf Baechle <ralf@linux-mips.org>,
	aaditya.kumar.30@gmail.com, kamezawa.hiroyu@jp.fujitsu.com,
	linux-mm@kvack.org, Johannes Weiner <hannes@cmpxchg.org>,
	Yinghai Lu <yinghai@kernel.org>
Subject: Re: + memory-hotplug-fix-kswapd-looping-forever-problem-fix-fix.patch added to -mm tree
Date: Fri, 20 Jul 2012 08:50:57 +0900	[thread overview]
Message-ID: <20120719235057.GA21012@bbox> (raw)
In-Reply-To: <20120719165750.GP24336@google.com>

On Thu, Jul 19, 2012 at 09:57:50AM -0700, Tejun Heo wrote:
> Hello,
> 
> On Thu, Jul 19, 2012 at 09:48:45AM +0900, Minchan Kim wrote:
> > > Maybe trigger warning if some fields which have to be zero aren't?
> > 
> > It's not good because this causes adding new WARNING in that part
> > whenever we add new field in pgdat. It nullify this patch's goal.
> 
> Maybe just do that on some fields?  The goal is catching unlikely case
> where archs leave the struct with garbage data.  I don't think full
> coverage is an absolute requirement.  Or reorganize the fields such

IIUC your previous reply, archs can use any fields during boot.
If so, we need full coverage for catching it.

> that fields unused by boot code is collected at the top so that it can
> be memset after certain offset?

If the fields touched by boot are limited, it's good idea.
Let me ask a question.
What fields are used by boot code before calling free_area_init_node
(excpet struct bootmem_data *bdata)?

> 
> But, really, given how the structure is used, I think we're better off
> just making sure all archs clear them and maybe have a sanity check or
> two just in case.  It's not like breakage on that front is gonna be
> subtle.

Of course, it seems all archs seems to zero-out already as I mentioned
(Not sure, MIPS) but Andrew doesn't want it. Andrew?

> 
> Thanks.
> 
> -- 
> tejun
> 
> --
> 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>

-- 
Kind regards,
Minchan Kim

--
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:[~2012-07-19 23:50 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20120717233115.A8E411E005C@wpzn4.hot.corp.google.com>
2012-07-18  1:22 ` + memory-hotplug-fix-kswapd-looping-forever-problem-fix-fix.patch added to -mm tree Minchan Kim
2012-07-18 21:38   ` Andrew Morton
2012-07-19  0:10     ` Minchan Kim
2012-07-19  0:21       ` Tejun Heo
2012-07-19  0:48         ` Minchan Kim
2012-07-19 16:57           ` Tejun Heo
2012-07-19 23:50             ` Minchan Kim [this message]
2012-07-20 17:15               ` Tejun Heo
2012-07-20 21:22               ` Andrew Morton
2012-07-20 21:36                 ` Tejun Heo
2012-07-23  4:58                   ` Minchan Kim
2012-07-23 15:42                     ` Tejun Heo
2012-07-24  1:11                       ` Minchan Kim

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=20120719235057.GA21012@bbox \
    --to=minchan@kernel.org \
    --cc=aaditya.kumar.30@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=hannes@cmpxchg.org \
    --cc=kamezawa.hiroyu@jp.fujitsu.com \
    --cc=linux-mm@kvack.org \
    --cc=ralf@linux-mips.org \
    --cc=tj@kernel.org \
    --cc=yinghai@kernel.org \
    /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).