From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx203.postini.com [74.125.245.203]) by kanga.kvack.org (Postfix) with SMTP id 4BCF76B002B for ; Wed, 7 Nov 2012 14:58:12 -0500 (EST) Date: Wed, 7 Nov 2012 11:58:10 -0800 From: Andrew Morton Subject: Re: [PATCH v11 5/7] virtio_balloon: introduce migration primitives to balloon pages Message-Id: <20121107115810.1ae286ac.akpm@linux-foundation.org> In-Reply-To: <265aaff9a79f503672f0cdcdff204114b5b5ba5b.1352256088.git.aquini@redhat.com> References: <265aaff9a79f503672f0cdcdff204114b5b5ba5b.1352256088.git.aquini@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Rafael Aquini Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Rusty Russell , "Michael S. Tsirkin" , Rik van Riel , Mel Gorman , Andi Kleen , Konrad Rzeszutek Wilk , Minchan Kim , Peter Zijlstra , "Paul E. McKenney" On Wed, 7 Nov 2012 01:05:52 -0200 Rafael Aquini wrote: > Memory fragmentation introduced by ballooning might reduce significantly > the number of 2MB contiguous memory blocks that can be used within a guest, > thus imposing performance penalties associated with the reduced number of > transparent huge pages that could be used by the guest workload. > > Besides making balloon pages movable at allocation time and introducing > the necessary primitives to perform balloon page migration/compaction, > this patch also introduces the following locking scheme, in order to > enhance the syncronization methods for accessing elements of struct > virtio_balloon, thus providing protection against concurrent access > introduced by parallel memory migration threads. > > ... > > @@ -122,18 +128,25 @@ static void set_page_pfns(u32 pfns[], struct page *page) > > static void fill_balloon(struct virtio_balloon *vb, size_t num) > { > + struct balloon_dev_info *vb_dev_info = vb->vb_dev_info; > + > + static DEFINE_RATELIMIT_STATE(fill_balloon_rs, > + DEFAULT_RATELIMIT_INTERVAL, > + DEFAULT_RATELIMIT_BURST); > + > /* We can only do one array worth at a time. */ > num = min(num, ARRAY_SIZE(vb->pfns)); > > + mutex_lock(&vb->balloon_lock); > for (vb->num_pfns = 0; vb->num_pfns < num; > vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { > - struct page *page = alloc_page(GFP_HIGHUSER | __GFP_NORETRY | > - __GFP_NOMEMALLOC | __GFP_NOWARN); > + struct page *page = balloon_page_enqueue(vb_dev_info); > + > if (!page) { > - if (printk_ratelimit()) > + if (__ratelimit(&fill_balloon_rs)) > dev_printk(KERN_INFO, &vb->vdev->dev, > "Out of puff! Can't get %zu pages\n", > - num); > + VIRTIO_BALLOON_PAGES_PER_PAGE); > /* Sleep for at least 1/5 of a second before retry. */ > msleep(200); > break; linux-next's fill_balloon() has already been converted to dev_info_ratelimited(). I fixed everything up. Please check the result. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org