From patchwork Wed Jul 27 11:34:03 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 107039 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 55587B6F77 for ; Wed, 27 Jul 2011 21:34:29 +1000 (EST) Received: from localhost ([::1]:48474 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qm2Ne-0002a9-II for incoming@patchwork.ozlabs.org; Wed, 27 Jul 2011 07:34:26 -0400 Received: from eggs.gnu.org ([140.186.70.92]:37737) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qm2NY-0002Zn-S5 for qemu-devel@nongnu.org; Wed, 27 Jul 2011 07:34:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Qm2NX-0004VG-Cg for qemu-devel@nongnu.org; Wed, 27 Jul 2011 07:34:20 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:51938) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qm2NX-0004Ue-3z for qemu-devel@nongnu.org; Wed, 27 Jul 2011 07:34:19 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e34.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p6RBYIFk027403 for ; Wed, 27 Jul 2011 05:34:18 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p6RBYHkq123964 for ; Wed, 27 Jul 2011 05:34:17 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p6R5XmSf002561 for ; Tue, 26 Jul 2011 23:33:50 -0600 Received: from skywalker.in.ibm.com.linux.vnet.ibm.com (skywalker.in.ibm.com [9.124.35.49]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p6R5XbqI001824; Tue, 26 Jul 2011 23:33:40 -0600 From: "Aneesh Kumar K.V" To: Stefan Hajnoczi , qemu-devel@nongnu.org In-Reply-To: <8739hs5a6n.fsf@skywalker.in.ibm.com> References: <1311672077-4592-1-git-send-email-stefanha@linux.vnet.ibm.com> <8739hs5a6n.fsf@skywalker.in.ibm.com> User-Agent: Notmuch/0.5-318-g52e4ded (http://notmuchmail.org) Emacs/23.2.1 (x86_64-pc-linux-gnu) Date: Wed, 27 Jul 2011 17:04:03 +0530 Message-ID: <87wrf43ql0.fsf@skywalker.in.ibm.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Received-From: 32.97.110.152 Cc: Kevin Wolf , Blue Swirl , Anthony Liguori , Venkateswararao Jujjuri , Stefan Hajnoczi Subject: Re: [Qemu-devel] [PATCH v8 0/5] Coroutines for better asynchronous programming X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org On Wed, 27 Jul 2011 15:15:20 +0530, "Aneesh Kumar K.V" wrote: > On Tue, 26 Jul 2011 10:21:12 +0100, Stefan Hajnoczi wrote: > > QEMU is event-driven and suffers when blocking operations are performed because > > VM execution may be stopped until the operation completes. Therefore many > > operations that could block are performed asynchronously and a callback is > > invoked when the operation has completed. This allows QEMU to continue > > executing while the operation is pending. > > > > The downside to callbacks is that they split up code into many smaller > > functions, each of which is a single step in a state machine that quickly > > becomes complex and hard to understand. Callback functions also result in lots > > of noise as variables are packed and unpacked into temporary structs that pass > > state to the callback function. > > > > This patch series introduces coroutines as a solution for writing asynchronous > > code while still having a nice sequential control flow. The semantics are > > explained in the second patch. The fourth patch adds automated tests. > > > > A nice feature of coroutines is that it is relatively easy to take synchronous > > code and lift it into a coroutine to make it asynchronous. Work has been done > > to move qcow2 request processing into coroutines and thereby make it > > asynchronous (today qcow2 will perform synchronous metadata accesses). This > > qcow2 work is still ongoing and not quite ready for mainline yet. > > > > v8: > > * Bisectability: introduce gthread implementation before ucontext/fibers > > Can we also get CoMutex and CoQueue patches also merged. I use them in > the VirtFS series. > > http://repo.or.cz/w/qemu/kevin.git/shortlog/refs/heads/coroutine-devel > http://repo.or.cz/w/qemu/v9fs.git/commit/318ef0b9b01cd296f8c30d8288139b9bed859892 > I have pushed VirtFS related changes to git://repo.or.cz/qemu/v9fs.git for-upstream-1 Once the co-routine patches are merged I can send a proper pull request. There are more changes pending for VirtFS. We will push them in batches. The following changes since commit c729e893aba79680bf410a2b9c671fb9e2c2c1a4: coroutine: add test-coroutine --benchmark-lifecycle (2011-07-27 16:30:26 +0530) are available in the git repository at: git://repo.or.cz/qemu/v9fs.git for-upstream-1 Aneesh Kumar K.V (32): hw/9pfs: Add yield support for readdir related coroutines hw/9pfs: Update v9fs_readdir to use coroutines hw/9pfs: Add yield support to statfs coroutine hw/9pfs: Update v9fs_statfs to use coroutines hw/9pfs: Add yield support to lstat coroutine hw/9pfs: Update v9fs_getattr to use coroutines hw/9pfs: Add yield support to setattr related coroutines hw/9pfs: Update v9fs_setattr to use coroutines hw/9pfs: Add yield support to xattr related coroutine hw/9pfs: Update v9fs_xattrwalk to coroutines hw/9pfs: Update v9fs_xattrcreate to use coroutines hw/9pfs: Add yield support to mknod coroutine hw/9pfs: Update v9fs_mknod to use coroutines hw/9pfs: Add yeild support to rename coroutine hw/9pfs: Update vfs_rename to use coroutines hw/9pfs: Add yeild support for fstat coroutine hw/9pfs: Update v9fs_lock to use coroutines hw/9pfs: Update v9fs_getlock to use coroutines hw/9pfs: Add yield support for open and opendir coroutine hw/9pfs: Update v9fs_open to use coroutines hw/9pfs: Update v9fs_stat to use coroutines hw/9pfs: Update v9fs_walk to use coroutines hw/9pfs: Add yeild support for clunk related coroutine hw/9pfs: Update v9fs_clunk to use coroutines hw/9pfs: Add yield support for fsync coroutine hw/9pfs: Update v9fs_fsync to use coroutines hw/9pfs: Add yield support for pwritev coroutine hw/9pfs: Update v9fs_write to use coroutines hw/9pfs: Update v9fs_wstat to use coroutines hw/9pfs: Update v9fs_attach to use coroutines hw/9pfs: Add yield support for preadv coroutine hw/9pfs: Update v9fs_read to use coroutines Harsh Prateek Bora (1): use readdir_r instead of readdir for reentrancy Venkateswararao Jujjuri (JV) (20): [virtio-9p] Add infrastructure to support glib threads and coroutines. [virtio-9p] Change all pdu handlers to coroutines. [virtio-9p] Remove post functions for v9fs_readlink. [virtio-9p] clean up v9fs_readlink. [virtio-9p] coroutines for readlink [virtio-9p] Remove post functions for v9fs_mkdir. [virtio-9p] clean up v9fs_mkdir. [virtio-9p] coroutine and threading for mkdir [virtio-9p] Remove post functions for v9fs_remove [virtio-9p] clean up v9fs_remove. [virtio-9p] coroutine and threading for remove/unlink [virtio-9p] Remove post functions for v9fs_lcreate [virtio-9p] clean up v9fs_lcreate [virtio-9p] coroutine and threading for open2 [virtio-9p] Remove post functions for v9fs_create [virtio-9p] clean up v9fs_create Rearrange the code [virtio-9p] Remove post functions for v9fs_symlink [virtio-9p] clean up v9fs_symlink [virtio-9p] coroutine and threading for v9fs_do_symlink [virtio-9p] coroutine and threading for v9fs_do_link Makefile.objs | 3 + fsdev/file-op-9p.h | 2 +- hw/9pfs/codir.c | 117 ++ hw/9pfs/cofile.c | 163 +++ hw/9pfs/cofs.c | 191 +++ hw/9pfs/coxattr.c | 84 ++ hw/9pfs/virtio-9p-coth.c | 102 ++ hw/9pfs/virtio-9p-coth.h | 96 ++ hw/9pfs/virtio-9p-device.c | 7 +- hw/9pfs/virtio-9p-local.c | 7 +- hw/9pfs/virtio-9p.c | 3052 ++++++++++++++++---------------------------- hw/9pfs/virtio-9p.h | 155 +--- 12 files changed, 1840 insertions(+), 2139 deletions(-) create mode 100644 hw/9pfs/codir.c create mode 100644 hw/9pfs/cofile.c create mode 100644 hw/9pfs/cofs.c create mode 100644 hw/9pfs/coxattr.c create mode 100644 hw/9pfs/virtio-9p-coth.c create mode 100644 hw/9pfs/virtio-9p-coth.h