On Thu, Oct 21, 2010 at 05:40:33PM +0900, Takuya Yoshikawa wrote: > Currently x86's kvm_vm_ioctl_get_dirty_log() needs to allocate a bitmap by > vmalloc() which will be used in the next logging and this has been causing > bad effect to VGA and live-migration: vmalloc() consumes extra systime, > triggers tlb flush, etc. > > This patch resolves this issue by pre-allocating one more bitmap and switching > between two bitmaps during dirty logging. > > Performance improvement: > I measured performance for the case of VGA update by trace-cmd. > So the result was 1.5 times faster than the original. > > > In the case of live migration, the improvement ratio depends on the workload > and the guest memory size. > > Note: > This does not change other architectures's logic but the allocation size > becomes twice. This will increase the actual memory consumption only when > the new size changes the number of pages allocated by vmalloc(). > > Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx> > Signed-off-by: Fernando Luis Vazquez Cao <fernando@xxxxxxxxxxxxx> Looks good to me. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
