From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48692) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bBK0X-0007sN-P6 for qemu-devel@nongnu.org; Fri, 10 Jun 2016 06:49:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bBK0R-0002p8-Tw for qemu-devel@nongnu.org; Fri, 10 Jun 2016 06:49:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44271) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bBK0R-0002oz-OU for qemu-devel@nongnu.org; Fri, 10 Jun 2016 06:49:39 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 52965C00F1DC for ; Fri, 10 Jun 2016 10:49:39 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" Date: Fri, 10 Jun 2016 11:49:31 +0100 Message-Id: <1465555776-23286-2-git-send-email-dgilbert@redhat.com> In-Reply-To: <1465555776-23286-1-git-send-email-dgilbert@redhat.com> References: <1465555776-23286-1-git-send-email-dgilbert@redhat.com> Subject: [Qemu-devel] [PATCH v5 1/6] Postcopy: Avoid 0 length discards List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: amit.shah@redhat.com, quintela@redhat.com From: "Dr. David Alan Gilbert" The discard code in migration/ram.c would send request for zero length discards in the case where no discards were needed. It doesn't appear to have had any bad effect. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Denis V. Lunev --- migration/ram.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index 844ea46..5f929d6 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1557,7 +1557,9 @@ static int postcopy_send_discard_bm_ram(MigrationState *ms, } else { discard_length = zero - one; } - postcopy_discard_send_range(ms, pds, one, discard_length); + if (discard_length) { + postcopy_discard_send_range(ms, pds, one, discard_length); + } current = one + discard_length; } else { current = one; -- 2.7.4