From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:49209) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S3XTq-0007M5-M2 for qemu-devel@nongnu.org; Fri, 02 Mar 2012 13:45:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S3XTo-00020d-V1 for qemu-devel@nongnu.org; Fri, 02 Mar 2012 13:45:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36018) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S3XTo-00020H-Mx for qemu-devel@nongnu.org; Fri, 02 Mar 2012 13:45:24 -0500 From: Kevin Wolf Date: Fri, 2 Mar 2012 19:48:48 +0100 Message-Id: <1330714131-16908-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [RFC PATCH 0/3] qcow2: Save requests during cluster allocation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, stefanha@gmail.com When a write request spans both allocated and unallocated clusters, qcow2 splits the request in two parts. This is not necessary if we have sequential writes: If the unallocated area can be allocated such that in the image file it is adjacent to the already allocated part, a single request is enough. Kevin Wolf (3): qcow2: Factor out count_cow_clusters qcow2: Add qcow2_alloc_clusters_at() qcow2: Reduce number of I/O requests block/qcow2-cluster.c | 274 +++++++++++++++++++++++++++++++++--------------- block/qcow2-refcount.c | 28 +++++ block/qcow2.h | 3 + trace-events | 1 + 4 files changed, 222 insertions(+), 84 deletions(-) -- 1.7.6.5