From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55841) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a3qiz-0007gn-M9 for qemu-devel@nongnu.org; Tue, 01 Dec 2015 14:36:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a3qiv-0008FF-Gg for qemu-devel@nongnu.org; Tue, 01 Dec 2015 14:36:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56935) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a3qiv-0008ES-8a for qemu-devel@nongnu.org; Tue, 01 Dec 2015 14:36:25 -0500 Date: Tue, 1 Dec 2015 19:36:18 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20151201193618.GE31209@work-vm> References: <1448357149-17572-1-git-send-email-zhang.zhanghailiang@huawei.com> <1448357149-17572-17-git-send-email-zhang.zhanghailiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448357149-17572-17-git-send-email-zhang.zhanghailiang@huawei.com> Subject: Re: [Qemu-devel] [PATCH COLO-Frame v11 16/39] ram/COLO: Record the dirty pages that SVM received List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: zhanghailiang Cc: lizhijian@cn.fujitsu.com, quintela@redhat.com, yunhong.jiang@intel.com, eddie.dong@intel.com, peter.huangpeng@huawei.com, qemu-devel@nongnu.org, arei.gonglei@huawei.com, stefanha@redhat.com, amit.shah@redhat.com, hongyang.yang@easystack.cn * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote: > We record the address of the dirty pages that received, > it will help flushing pages that cached into SVM. > We record them by re-using migration dirty bitmap. > > Signed-off-by: zhanghailiang > --- > v11: > - Split a new helper function from original > host_from_stream_offset() (Dave's suggestion) > - Only do recording work in this patch > v10: > - New patch split from v9's patch 13 > - Rebase to master to use 'migration_bitmap_rcu' > --- > migration/ram.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/migration/ram.c b/migration/ram.c > index 9d946a1..da6bbd6 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -2153,6 +2153,7 @@ static inline RAMBlock *ram_block_from_stream(QEMUFile *f, > > return block; > } > + > len = qemu_get_byte(f); > qemu_get_buffer(f, (uint8_t *)id, len); > id[len] = 0; That blank should probably go, but other than that: Reviewed-by: Dr. David Alan Gilbert Dave > @@ -2179,10 +2180,23 @@ static inline void *host_from_ram_block_offset(RAMBlock *block, > static inline void *colo_cache_from_block_offset(RAMBlock *block, > ram_addr_t offset) > { > + unsigned long *bitmap; > + long k; > + > if (!block) { > return NULL; > } > > + k = (block->mr->ram_addr + offset) >> TARGET_PAGE_BITS; > + bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; > + /* > + * During colo checkpoint, we need bitmap of these migrated pages. > + * It help us to decide which pages in ram cache should be flushed > + * into VM's RAM later. > + */ > + if (!test_and_set_bit(k, bitmap)) { > + migration_dirty_pages++; > + } > return block->colo_cache + offset; > } > > @@ -2573,6 +2587,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > int colo_init_ram_cache(void) > { > RAMBlock *block; > + int64_t ram_cache_pages = last_ram_offset() >> TARGET_PAGE_BITS; > > rcu_read_lock(); > QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { > @@ -2587,6 +2602,15 @@ int colo_init_ram_cache(void) > } > rcu_read_unlock(); > ram_cache_enable = true; > + /* > + * Record the dirty pages that sent by PVM, we use this dirty bitmap together > + * with to decide which page in cache should be flushed into SVM's RAM. Here > + * we use the same name 'migration_bitmap_rcu' as for migration. > + */ > + migration_bitmap_rcu = g_new0(struct BitmapRcu, 1); > + migration_bitmap_rcu->bmap = bitmap_new(ram_cache_pages); > + migration_dirty_pages = 0; > + > return 0; > > out_locked: > @@ -2604,9 +2628,15 @@ out_locked: > void colo_release_ram_cache(void) > { > RAMBlock *block; > + struct BitmapRcu *bitmap = migration_bitmap_rcu; > > ram_cache_enable = false; > > + atomic_rcu_set(&migration_bitmap_rcu, NULL); > + if (bitmap) { > + call_rcu(bitmap, migration_bitmap_free, rcu); > + } > + > rcu_read_lock(); > QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { > if (block->colo_cache) { > -- > 1.8.3.1 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK