lkml.org 
[lkml]   [2010]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 3/3] NFS: Fix a memory leak in nfs_readdir
On Wed, Dec 1, 2010 at 3:36 PM, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Wed, 1 Dec 2010 15:31:11 -0800
> Linus Torvalds <torvalds@linux-foundation.org> wrote:
>>
>> Ergo: vmscan has a locked page leads to the filesystem being
>> guaranteed to not be unmounted.  And that, in turn, guarantees that
>> the module won't be unloaded until the machine has gone through an
>> idle cycle.
>
> The page isn't attached to the address_space any more:

Did you even read the email?

Here, let me quote the important parts:

"module won't be unloaded until the machine has gone through an idle cycle"

"This is pretty much how all the module races are handled. Doing module
ref-counts per page (or per packet in flight for things like
networking) would be prohibitively expensive."

IOW, the whole "stop_machine()" part is fundamental. That whole
"module unload won't happen until we've gone through an idle cycle" is
EXACTLY why we don't need to have the page attached or ref-counted -
we're still safe.

Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-12-02 02:09    [W:0.149 / U:0.524 seconds]
©2003-2014 Jasper Spaans. Advertise on this site