From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55413) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dDgpZ-0006FF-Ea for qemu-devel@nongnu.org; Wed, 24 May 2017 20:40:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dDgpW-0004RY-AJ for qemu-devel@nongnu.org; Wed, 24 May 2017 20:40:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39580) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dDgpW-0004R3-1g for qemu-devel@nongnu.org; Wed, 24 May 2017 20:40:42 -0400 Date: Thu, 25 May 2017 08:40:33 +0800 From: Peter Xu Message-ID: <20170525004033.GQ3873@pxdev.xzpeter.org> References: <1495642203-12702-1-git-send-email-felipe@nutanix.com> <1495642203-12702-4-git-send-email-felipe@nutanix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1495642203-12702-4-git-send-email-felipe@nutanix.com> Subject: Re: [Qemu-devel] [PATCH 3/4] migration: set bytes_xfer_* outside of autoconverge logic List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Felipe Franciosi Cc: Juan Quintela , "Jason J. Herne" , amit Shah , "Dr. David Alan Gilbert" , Malcolm Crossley , "qemu-devel@nongnu.org" On Wed, May 24, 2017 at 05:10:02PM +0100, Felipe Franciosi wrote: > The bytes_xfer_now/prev counters are only used by the auto convergence > logic. However, they are used alongside the dirty_pages_rate counter, > which is calculated (and required) outside of this logic. The problem > with this approach is that if the auto convergence capability is changed > while a migration is ongoing, the relationship of the counters will be > broken. > > This moves the management of bytes_xfer_now/prev counters outside of the > auto convergence logic to address this issue. > > Signed-off-by: Felipe Franciosi Reviewed-by: Peter Xu > --- > migration/ram.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/migration/ram.c b/migration/ram.c > index 495ecbe..1a3d9e6 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -697,6 +697,7 @@ static void migration_bitmap_sync(RAMState *rs) > /* calculate period counters */ > rs->dirty_pages_rate = rs->num_dirty_pages_period * 1000 > / (end_time - rs->time_last_bitmap_sync); > + bytes_xfer_now = ram_bytes_transferred(); > > if (migrate_auto_converge()) { > /* The following detection logic can be refined later. For now: > @@ -704,7 +705,6 @@ static void migration_bitmap_sync(RAMState *rs) > amount of bytes that just got transferred since the last time we > were in this routine. If that happens twice, start or increase > throttling */ > - bytes_xfer_now = ram_bytes_transferred(); > > if ((rs->num_dirty_pages_period * TARGET_PAGE_SIZE > > (bytes_xfer_now - rs->bytes_xfer_prev) / 2) && > @@ -713,7 +713,6 @@ static void migration_bitmap_sync(RAMState *rs) > rs->dirty_rate_high_cnt = 0; > mig_throttle_guest_down(); > } > - rs->bytes_xfer_prev = bytes_xfer_now; > } > > if (migrate_use_xbzrle()) { > @@ -730,6 +729,7 @@ static void migration_bitmap_sync(RAMState *rs) > /* reset period counters */ > rs->time_last_bitmap_sync = end_time; > rs->num_dirty_pages_period = 0; > + rs->bytes_xfer_prev = bytes_xfer_now; > } > if (migrate_use_events()) { > qapi_event_send_migration_pass(rs->bitmap_sync_count, NULL); > -- > 1.9.5 > -- Peter Xu