CFS: Linux VM recursion fix

--===============8503793943645361727==
Content-Type: multipart/alternative; boundary=bcaec548a5f93b5c8a04b1dd58ee

--bcaec548a5f93b5c8a04b1dd58ee
Content-Type: text/plain; charset=ISO-8859-1

Hi,

The latest CVS check-in fixes a potential corruption at CFS server due to
recursion.  The bug was CFS inherited the backing device info of the
backing file system.  The Linux VM is re-entrant at balance_dirty_pages()
and can call CFS recursively when the backing device info are the same on
both file systems.

CFS -> VM -> PFS -> VM -> CFS -> VM -> PFS ...

The Linux VM may not call this far down and may not traverse file systems
exactly as shown but if this happens you may get stack overflow, etc.

The fix should increase interactiveness and decrease latency since the VM
no longer makes recursive calls at balance_dirty_pages().

-Roger

--bcaec548a5f93b5c8a04b1dd58ee
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

Hi,<br><br>The latest CVS check-in fixes a potential corruption at CFS serv=
er due to recursion.=A0 The bug was CFS inherited the backing device info o=
f the backing file system.=A0 The Linux VM is re-entrant at balance_dirty_p=
ages() and can call CFS recursively when the backing device info are the sa=
me on both file systems.<br>
<br>CFS -&gt; VM -&gt; PFS -&gt; VM -&gt; CFS -&gt; VM -&gt; PFS ...<br><br=
>The Linux VM may not call this far down and may not traverse file systems =
exactly as shown but if this happens you may get stack overflow, etc.<br>
<br>The fix should increase interactiveness and decrease latency since the =
VM no longer makes recursive calls at balance_dirty_pages().<br><br>-Roger<=
br>

--bcaec548a5f93b5c8a04b1dd58ee--


--===============8503793943645361727==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

------------------------------------------------------------------------------
All the data continuously generated in your IT infrastructure 
contains a definitive record of customers, application performance, 
security threats, fraudulent activity, and more. Splunk takes this 
data and makes sense of it. IT sense. And common sense.
http://p.sf.net/sfu/splunk-novd2d
--===============8503793943645361727==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
ssic-linux-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/ssic-linux-devel

--===============8503793943645361727==--