Re: [Xen-devel] LVM Snapshot Troubles

[Ian Pratt <Ian.Pratt@xxxxxxxxxxxx>]

> On Tue, Sep 28, 2004 at 04:43:25PM +0100, Ian Pratt wrote:
> > There's nothing in slabinfo that looks crazy. I wander where all
> > your memory is gone? BTW: how big is your dom0? 
> > 
> > It's possible that dm-io or kcopyd is chewing up pages (which
> > won't show up in the slab allocator). I'm surprised they're not
> > just transient, though.
> 
> When I've run into memory trouble with snapshots, I've always seen a
> stack backtrace that points me at kcopyd_client_create.  Following the
> code: when creating a snapshot, a new kcopyd client is created with 256
> (SNAPSHOT_PAGES in dm-snap.c) pages (= 1 MB) dedicated to that snapshot.
> I think I managed to dig up the logs from one of the failures I've seen;
> I've attached them to this message.

It might be worth adding "| __GFP_REPEAT" to the alloc_page in 
drivers/md/kcopyd.c

If this fixes things, we could probably get the patch accepted
into mainline Linux.

(Of course, GFP_REPEAT may be a nop under Linux's VM...)

Ian



-------------------------------------------------------
This SF.net email is sponsored by: IT Product Guide on ITManagersJournal
Use IT products in your business? Tell us what you think of them. Give us
Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more
http://productguide.itmanagersjournal.com/guidepromo.tmpl
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel