[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH] scrub pages on guest termination



The aim of the loop was to scrub enough pages in a batch that lock contention is kept tolerably low. Even if 16 pages is not sufficient for that, I’m surprised a ‘node’ (you mean a whole system, presumably?) would appear to lock up. Maybe pages would be scrubbed slower than we’d like, but still CPUs should be able to get the spinlock often enough to evaluate whether they have spent 1ms in the loop and hence get out of there.

What sort of system were you seeing the lockup on? Does it have very many physical CPUs?

 -- Keir

On 23/5/08 16:00, "Ben Guthro" <bguthro@xxxxxxxxxxxxxxx> wrote:

This patch solves the following problem.  When a large VS terminates, the node locks
up. The node locks up because the page_scrub_kick routine sends a softirq to
all processors instructing them to run the page scrub code.  There they interfere
with each other as they serialize behind the page_scrub_lock.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.