Mounts to Windows 7 and "out of memory" or "insufficient server resources"

Steve French smfrench at
Wed Sep 28 12:25:07 MDT 2011

On Wed, Sep 28, 2011 at 7:00 AM, Jeff Layton <jlayton at> wrote:
> On Tue, 27 Sep 2011 16:36:22 -0500
> Steve French <smfrench at> wrote:
>> FYI - The cifs async write in 3.0 seems to exacerbate problems running
>> out of memory (apparently) on the Windows 7 system (running as a
>> server) after a large file copy to the server completes.   I have been
>> able to reproduce the same problem on Windows Vista Service Pack 2
>> (which is a good news/bad news story since my earlier testing on
>> Windows Vista showed hangs on some requests rather than returning out
>> of memory).  Does not seem to be a problem with any of the Windows
>> server versions just Windows 7 and Vista so far.
>> As Pavel noted in an earlier note, increasing MaxWorkItems to 4096 in
>> the Windows registry solves this.
>> The cifs async write code does increase large file copy speed
>> dramatically (more than 15% in most environments) - but we are working
>> through how to handle the Windows7/WindowsVista problem to see if
>> there are workarounds.
> This is seems likely to be a cifs.ko bug -- it does not respect the
> MaxReq parm that the server sends in the negotiate and instead uses a
> hardcoded limit of 50 requests (which is tunable via module parm).
> What value is the server sending in the NEGOTIATE? Ensuring that
> cifs.ko doesn't exceed that value seems like a worthwhile endeavor.
> This is likely to be even worse soon when the async read patches are
> merged.

Yes, the client should not be exceeding the limit, but more testing
is needed of my earlier patch for that.



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