Ulrich Drepper wrote:
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Izik Eidus wrote:
+ if (!kvm_x86_ops->dirty_bit_support()) {
+ spin_lock(&kvm->mmu_lock);
+ /* remove_write_access() flush the tlb */
+ kvm_mmu_slot_remove_write_access(kvm, log->slot);
+ spin_unlock(&kvm->mmu_lock);
+ } else {
+ kvm_flush_remote_tlbs(kvm);
Hi.
It might not correspond to the common style, but I think a callback
function ->dirty_bit_support is overkill. This is a function pointer
the compiler cannot see through. Hence it's an indirect function call.
But the implementation is always a simple yes/no (it seems). Indirect
calls are rather expensive (most of the time they cannot be predicted
right).
This function pointer will be called once every ioctl to get the dirty
bit tracking, so i dont think it is a big issue (normal 30 times a sec)
Why not instead have a read-only data constants and have an inline
function test that value? It means no function call and only one data
access.
May be relevent, but i dont sure if it is needed optimization for this
patch consider the amount of time ->dirty_bit_support() will be called
Also, you're inconsistent in the use of integers and true/false in the
implementations of this function. Either use 0/1 or false/true.
I will fix it, thanks.
- --
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
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