All of lore.kernel.org
 help / color / mirror / Atom feed
From: Richard Weinberger <richard@nod.at>
To: Real Name <enjoymindful@gmail.com>,
	user-mode-linux-devel@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] delete unnecessary bootmem struct page array
Date: Sun, 01 Jun 2014 15:57:31 +0200	[thread overview]
Message-ID: <538B314B.2050604@nod.at> (raw)
In-Reply-To: <1401628131-1948-2-git-send-email-enjoymindful@gmail.com>

Am 01.06.2014 15:08, schrieb Real Name:
> From: Honggang Li <enjoymindful@gmail.com>
> 
> 1) uml kernel bootmem managed through bootmem_data->node_bootmem_map,
> not the struct page array, so the array is unnecessary.
> 
> 2) the bootmem struct page array has been pointed by a *local* pointer,
> struct page *map, in init_maps function. The array can be accessed only
> in init_maps's scope. As a result, uml kernel wastes about 1% of total
> memory.

I reread your patch again.
You missed one important point. init_maps() setups max_mapnr which is used by
virt_addr_valid().

We have to be extremely careful here to not introduce a subtle fuckup.

Thanks,
//richard

  reply	other threads:[~2014-06-01 13:57 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-01 13:08 [PATCH] delete unnecessary bootmem struct page array Real Name
2014-06-01 13:08 ` Real Name
2014-06-01 13:57   ` Richard Weinberger [this message]
  -- strict thread matches above, loose matches on Subject: below --
2014-06-03  5:30 [uml-devel] [PATCH v2] " Real Name
2014-06-03  5:30 ` [PATCH] " Real Name
2014-06-01  0:24 Real Name
2014-06-01  7:54 ` Richard Weinberger
2014-05-31 23:34 Real Name
2014-06-01  0:12 ` Real Name

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=538B314B.2050604@nod.at \
    --to=richard@nod.at \
    --cc=enjoymindful@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=user-mode-linux-devel@lists.sourceforge.net \
    /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.