Re: [Xen-devel] [PATCH v2 1/3] replace vCPU's dirty CPU mask by numeric ID

2018-01-23 Thread Julien Grall
Hi Jan, On 23/01/18 10:12, 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 VCPU_CPU_CLEAN if no di

Re: [Xen-devel] [PATCH v2 1/3] replace vCPU's dirty CPU mask by numeric ID

2018-01-23 Thread Andrew Cooper
On 23/01/2018 10:12, Jan Beulich wrote: > @@ -803,6 +803,11 @@ static inline int vcpu_runnable(struct v > atomic_read(&v->domain->pause_count)); > } > > +static inline bool vcpu_cpu_dirty(const struct vcpu *v) > +{ Oh - one extra through.  BUILD_BUG_ON(NR_CPUS >= VCPU_CPU_CLEAN) ?

[Xen-devel] [PATCH v2 1/3] replace vCPU's dirty CPU mask by numeric ID

2018-01-23 Thread Jan Beulich
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 VCPU_CPU_CLEAN if no dirty state exists. Signed-off-by: Jan Beulich --