>>> On 19.01.18 at 18:48, <andrew.coop...@citrix.com> wrote: > On 19/01/18 16:06, Jan Beulich wrote: >> At most one bit can be set in the masks, so especially on larger systems >> it's quite a bit of unnecessary memory and processing overhead to track >> the information as a mask. Store the numeric ID of the respective CPU >> instead, or NR_CPUS if no dirty state exists. >> >> Signed-off-by: Jan Beulich <jbeul...@suse.com> > > Definitely +1 for this change. > > However, the comparison against nr_cpu_ids isn't completely obvious as > to its function. How about introducing a predicate such as vcpu_dirty() > which wraps the use of the id?
I can do that. > Also, you'd get better code by using NR_CPUS which is a compile-time > constant, rather than nr_cpu_ids which would be a memory read. I did consider it, but decided that the check being more tight when using nr_cpu_ids is preferable. The checks sit in ASSERT()s only anyway, i.e. I don't think performance matters much. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
