On 12/27/2011 05:03 PM, Takuya Yoshikawa wrote: > Avi Kivity <avi@xxxxxxxxxx> wrote: > > > > It should not be necessary, atomicity of updates to > > > memslot->dirty_bitmap, because of RCU updates to the memslot pointer > > > (note memslot = gfn_to_memslot(kvm, gfn); in mark_page_dirty). > > > > > > The order is: > > > > > > - update page data. > > > - grab memslot pointer. > > > - set page bit in memslot. > > > > > > > What if both grab the same memslot pointer, but set different bits? > > (Sorry for my bad wording, that is what I wanted to explain.) > > There seems to be possible concurrent __set_bit()'s to the same word > which will result in bit loss. > > I was thinking to change the kvm-unit-tests' dirty log test to write > to two consecutive pages concurrently. Is this good for debugging this? Yes, it already tests some concurrency issues. Please do write the test, we should do this a lot more often. -- error compiling committee.c: too many arguments to function -- 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
