From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: kosaki.motohiro@jp.fujitsu.com,
Andrew Morton <akpm@linux-foundation.org>,
Andy Grover <andy.grover@oracle.com>,
linux-kernel@vger.kernel.org, mingo@redhat.com, npiggin@suse.de
Subject: Re: [PATCH 1/1] Document get_user_pages_fast()
Date: Fri, 10 Apr 2009 13:13:59 +0900 (JST) [thread overview]
Message-ID: <20090410131200.793C.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <20090410121923.7939.A69D9226@jp.fujitsu.com>
> > > and Cow change owner process.
> >
> > hm. buggy userspace? Why is that a problem from a kernel perspective?
>
> We already started to discuttion in "[PATCH] fork vs gup(-fast) fix" thread.
> but this is very difficult problem. it is still in progress ;)
note:
access_process_vm() tell us right get_user_pages() usage.
mmap_sem prevent fork in critical section. then it don't have cow risk.
> > > Yes, current all gup caller have serious bug. especially direct-io, aio, bio
> > > are broken.
prev parent reply other threads:[~2009-04-10 4:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-10 0:44 [PATCH 1/1] Document get_user_pages_fast() Andy Grover
2009-04-10 2:17 ` KOSAKI Motohiro
2009-04-10 3:13 ` Andrew Morton
2009-04-10 3:27 ` KOSAKI Motohiro
2009-04-10 4:13 ` KOSAKI Motohiro [this message]
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