From: Paul Menage <menage@google.com>
To: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Balbir Singh <balbir@linux.vnet.ibm.com>,
linux-mm@kvack.org
Subject: Re: [PATCH 1/7] mm: remove cgroup_mm_owner_callbacks
Date: Wed, 19 Nov 2008 17:23:31 -0800 [thread overview]
Message-ID: <6599ad830811191723v3c346a17kf5ae5494987373c1@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0811200110180.19216@blonde.site>
On Wed, Nov 19, 2008 at 5:11 PM, Hugh Dickins <hugh@veritas.com> wrote:
>
> assign_new_owner:
> BUG_ON(c == p);
> get_task_struct(c);
> - read_unlock(&tasklist_lock);
> - down_write(&mm->mmap_sem);
> /*
> * The task_lock protects c->mm from changing.
> * We always want mm->owner->mm == mm
> */
> task_lock(c);
> + /*
> + * Delay read_unlock() till we have the task_lock()
> + * to ensure that c does not slip away underneath us
> + */
> + read_unlock(&tasklist_lock);
How can c slip away when we've done get_task_struct(c) earlier?
Paul
--
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>
next prev parent reply other threads:[~2008-11-20 1:23 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-20 1:10 [PATCH 0/7] mm: cleanups Hugh Dickins
2008-11-20 1:11 ` [PATCH 1/7] mm: remove cgroup_mm_owner_callbacks Hugh Dickins
2008-11-20 1:23 ` Paul Menage [this message]
2008-11-20 1:26 ` Hugh Dickins
2008-11-20 16:41 ` Balbir Singh
2008-11-20 1:14 ` [PATCH 2/7] mm: remove AOP_WRITEPAGE_ACTIVATE Hugh Dickins
2008-11-20 1:16 ` [PATCH 3/7] mm: remove GFP_HIGHUSER_PAGECACHE Hugh Dickins
2008-11-20 16:43 ` Mel Gorman
2008-11-20 18:58 ` Hugh Dickins
2008-11-21 10:46 ` Mel Gorman
2008-11-20 1:17 ` [PATCH 4/7] mm: add Set,ClearPageSwapCache stubs Hugh Dickins
2008-11-20 18:08 ` Christoph Lameter
2008-11-20 1:20 ` [PATCH 5/7] mm: replace some BUG_ONs by VM_BUG_ONs Hugh Dickins
2008-11-20 18:09 ` Christoph Lameter
2008-11-20 1:22 ` [PATCH 6/7] mm: add_active_or_unevictable into rmap Hugh Dickins
2008-11-20 2:08 ` Rik van Riel
2008-11-20 15:18 ` Lee Schermerhorn
2008-11-23 21:51 ` [PATCH 8/7] mm: further cleanup page_add_new_anon_rmap Hugh Dickins
2008-11-23 21:56 ` Rik van Riel
2008-11-23 22:18 ` Hugh Dickins
2008-11-23 22:41 ` Rik van Riel
2008-11-20 1:24 ` [PATCH 7/7] mm: make page_lock_anon_vma static Hugh Dickins
2008-11-21 8:29 ` KOSAKI Motohiro
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=6599ad830811191723v3c346a17kf5ae5494987373c1@mail.gmail.com \
--to=menage@google.com \
--cc=akpm@linux-foundation.org \
--cc=balbir@linux.vnet.ibm.com \
--cc=hugh@veritas.com \
--cc=linux-mm@kvack.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