On Mon, Jul 23, 2018 at 04:44:49PM +0800, Xiao Guangrong wrote: [...] > > > > > > However, it is not safe to do ram_release_pages in the thread as it's > > > not protected it multithreads. Fortunately, compression will be disabled > > > if it switches to post-copy, so i preferred to keep current behavior and > > > deferred to fix it after this patchset has been merged. > > > > Do you mean ram_release_pages() is not thread-safe? Why? I didn't > > notice it before but I feel like it is safe. > > bitmap_clear() called in the function is not safe. Yeah, and the funny thing is that I don't think ram_release_pages() should even touch the receivedmap... It's possible that the release-ram feature for postcopy is broken. Never mind on that. I'll post a patch to fix it, then I think the ram_release_pages() will be thread safe. Then this patch shouldn't be affected and it should be fine after that fix. Regards, -- Peter Xu
