Re: [Xen-devel] [RFC PATCH 2/2] gnttab: refactor locking for better scalability

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 12.11.13 at 18:58, Matt Wilson <msw@xxxxxxxxx> wrote:
> Do you have any thoughts on padding the spinlock out to a
> cache line to avoid false sharing of the other elements?

Wouldn't that be counter productive? Once you need to acquire the
lock, you need ownership on the line anyway, and hence it seems
desirable to have the other elements in the same cache line. Unless
of course there are significant parts here that are read-mostly (but
I concluded from your use of a spin lock rather than an rw one that
there generally are modifications done when holding the lock).

What we may want to push out of it are elements outside the
maptrack sub-structure.

Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel