From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43834) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fSe4b-0007Tq-16 for qemu-devel@nongnu.org; Tue, 12 Jun 2018 03:50:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fSe4W-0003tU-3F for qemu-devel@nongnu.org; Tue, 12 Jun 2018 03:50:37 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35938 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fSe4V-0003tD-KM for qemu-devel@nongnu.org; Tue, 12 Jun 2018 03:50:31 -0400 Date: Tue, 12 Jun 2018 15:50:16 +0800 From: Peter Xu Message-ID: <20180612075016.GD15344@xz-mi> References: <1528445443-43406-1-git-send-email-wei.w.wang@intel.com> <1528445443-43406-5-git-send-email-wei.w.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1528445443-43406-5-git-send-email-wei.w.wang@intel.com> Subject: Re: [Qemu-devel] [PATCH v8 4/6] migration/ram.c: add ram save state notifiers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wei Wang Cc: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com On Fri, Jun 08, 2018 at 04:10:41PM +0800, Wei Wang wrote: > This patch adds a ram save state notifier list, and expose RAMState for > the notifer callbacks to use. > > Signed-off-by: Wei Wang > CC: Dr. David Alan Gilbert > CC: Juan Quintela > CC: Michael S. Tsirkin > CC: Peter Xu > --- > include/migration/misc.h | 52 +++++++++++++++++++++++++++++++++++++++ > migration/ram.c | 64 +++++++++++++++++------------------------------- > 2 files changed, 75 insertions(+), 41 deletions(-) > > diff --git a/include/migration/misc.h b/include/migration/misc.h > index 113320e..b970d7d 100644 > --- a/include/migration/misc.h > +++ b/include/migration/misc.h > @@ -16,9 +16,61 @@ > > #include "exec/cpu-common.h" > #include "qemu/notify.h" > +#include "qemu/thread.h" > > /* migration/ram.c */ > > +typedef enum RamSaveState { > + RAM_SAVE_ERR = 0, > + RAM_SAVE_RESET = 1, > + RAM_SAVE_BEFORE_SYNC_BITMAP = 2, > + RAM_SAVE_AFTER_SYNC_BITMAP = 3, > + RAM_SAVE_MAX = 4, > +} RamSaveState; > + > +/* State of RAM for migration */ > +typedef struct RAMState { > + /* QEMUFile used for this migration */ > + QEMUFile *f; > + /* Last block that we have visited searching for dirty pages */ > + RAMBlock *last_seen_block; > + /* Last block from where we have sent data */ > + RAMBlock *last_sent_block; > + /* Last dirty target page we have sent */ > + ram_addr_t last_page; > + /* last ram version we have seen */ > + uint32_t last_version; > + /* We are in the first round */ > + bool ram_bulk_stage; > + /* How many times we have dirty too many pages */ > + int dirty_rate_high_cnt; > + /* ram save states used for notifiers */ > + int ram_save_state; > + /* these variables are used for bitmap sync */ > + /* last time we did a full bitmap_sync */ > + int64_t time_last_bitmap_sync; > + /* bytes transferred at start_time */ > + uint64_t bytes_xfer_prev; > + /* number of dirty pages since start_time */ > + uint64_t num_dirty_pages_period; > + /* xbzrle misses since the beginning of the period */ > + uint64_t xbzrle_cache_miss_prev; > + /* number of iterations at the beginning of period */ > + uint64_t iterations_prev; > + /* Iterations since start */ > + uint64_t iterations; > + /* number of dirty bits in the bitmap */ > + uint64_t migration_dirty_pages; > + /* protects modification of the bitmap */ > + QemuMutex bitmap_mutex; > + /* The RAMBlock used in the last src_page_requests */ > + RAMBlock *last_req_rb; > + /* Queue of outstanding page requests from the destination */ > + QemuMutex src_page_req_mutex; > + QSIMPLEQ_HEAD(src_page_requests, RAMSrcPageRequest) src_page_requests; > +} RAMState; Why move these chunk? Can it be avoided? > + > +void add_ram_save_state_change_notifier(Notifier *notify); > void ram_mig_init(void); > void qemu_guest_free_page_hint(void *addr, size_t len); > > diff --git a/migration/ram.c b/migration/ram.c > index 237f11e..d45b5a4 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -56,6 +56,9 @@ > #include "qemu/uuid.h" > #include "savevm.h" > > +static NotifierList ram_save_state_notifiers = > + NOTIFIER_LIST_INITIALIZER(ram_save_state_notifiers); > + > /***********************************************************/ > /* ram save/restore */ > > @@ -267,49 +270,18 @@ struct RAMSrcPageRequest { > QSIMPLEQ_ENTRY(RAMSrcPageRequest) next_req; > }; > > -/* State of RAM for migration */ > -struct RAMState { > - /* QEMUFile used for this migration */ > - QEMUFile *f; > - /* Last block that we have visited searching for dirty pages */ > - RAMBlock *last_seen_block; > - /* Last block from where we have sent data */ > - RAMBlock *last_sent_block; > - /* Last dirty target page we have sent */ > - ram_addr_t last_page; > - /* last ram version we have seen */ > - uint32_t last_version; > - /* We are in the first round */ > - bool ram_bulk_stage; > - /* How many times we have dirty too many pages */ > - int dirty_rate_high_cnt; > - /* these variables are used for bitmap sync */ > - /* last time we did a full bitmap_sync */ > - int64_t time_last_bitmap_sync; > - /* bytes transferred at start_time */ > - uint64_t bytes_xfer_prev; > - /* number of dirty pages since start_time */ > - uint64_t num_dirty_pages_period; > - /* xbzrle misses since the beginning of the period */ > - uint64_t xbzrle_cache_miss_prev; > - /* number of iterations at the beginning of period */ > - uint64_t iterations_prev; > - /* Iterations since start */ > - uint64_t iterations; > - /* number of dirty bits in the bitmap */ > - uint64_t migration_dirty_pages; > - /* protects modification of the bitmap */ > - QemuMutex bitmap_mutex; > - /* The RAMBlock used in the last src_page_requests */ > - RAMBlock *last_req_rb; > - /* Queue of outstanding page requests from the destination */ > - QemuMutex src_page_req_mutex; > - QSIMPLEQ_HEAD(src_page_requests, RAMSrcPageRequest) src_page_requests; > -}; > -typedef struct RAMState RAMState; > - > static RAMState *ram_state; > > +void add_ram_save_state_change_notifier(Notifier *notify) > +{ > + notifier_list_add(&ram_save_state_notifiers, notify); > +} > + > +static void notify_ram_save_state_change_notifier(void) > +{ > + notifier_list_notify(&ram_save_state_notifiers, ram_state); > +} > + > uint64_t ram_bytes_remaining(void) > { > return ram_state ? (ram_state->migration_dirty_pages * TARGET_PAGE_SIZE) : > @@ -1139,6 +1111,9 @@ static void migration_bitmap_sync(RAMState *rs) > int64_t end_time; > uint64_t bytes_xfer_now; > > + rs->ram_save_state = RAM_SAVE_BEFORE_SYNC_BITMAP; What's the point to keep this state after all?... > + notify_ram_save_state_change_notifier(); > + > ram_counters.dirty_sync_count++; > > if (!rs->time_last_bitmap_sync) { > @@ -1205,6 +1180,9 @@ static void migration_bitmap_sync(RAMState *rs) > if (migrate_use_events()) { > qapi_event_send_migration_pass(ram_counters.dirty_sync_count, NULL); > } > + > + rs->ram_save_state = RAM_SAVE_AFTER_SYNC_BITMAP; > + notify_ram_save_state_change_notifier(); > } > > /** > @@ -1961,6 +1939,8 @@ static void ram_state_reset(RAMState *rs) > rs->last_page = 0; > rs->last_version = ram_list.version; > rs->ram_bulk_stage = true; > + rs->ram_save_state = RAM_SAVE_RESET; ... and this state is much more meaningless afaict ... > + notify_ram_save_state_change_notifier(); > } > > #define MAX_WAIT 50 /* ms, half buffered_file limit */ > @@ -2709,6 +2689,8 @@ out: > > ret = qemu_file_get_error(f); > if (ret < 0) { > + rs->ram_save_state = RAM_SAVE_ERR; > + notify_ram_save_state_change_notifier(); > return ret; > } Also, I would prefer to add a general event framework for migration rather than "ram save" specific. Then we add SYNC_START/SYNC_END events. These notifiers aren't a lot, it'll be a bit awkward to introduce the framework multiple times for similar purpuse (after we have a common notifier we can merge the postcopy notifiers AFAIU). Regards, -- Peter Xu