The newly added function v9fs_co_readdir_many() retrieves multiple
directory entries with a single fs driver request. It is intended to
replace uses of v9fs_co_readdir(), the latter only retrieves a
single directory entry per fs driver request instead.
The reason for this planned replacement is that for every fs driver
request the coroutine is dispatched from main I/O thread to a
background I/O thread and eventually dispatched back to main I/O
thread. Hopping between threads adds latency. So if a 9pfs Treaddir
request reads a large amount of directory entries, this currently
sums up to huge latencies of several hundred ms or even more. So
using v9fs_co_readdir_many() instead of v9fs_co_readdir() will
provide significant performance improvements.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <73dc827a12ef577ae7e644dcf34a5c0e443ab42f.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
The implementation of v9fs_co_readdir() has two parts: the outer
part is executed by main I/O thread, whereas the inner part is
executed by fs driver on a background I/O thread.
Move the inner part to its own new, private function do_readdir(),
so it can be shared by another upcoming new function.
This is just a preparatory patch for the subsequent patch, with the
purpose to avoid the next patch to clutter the overall diff.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <a426ee06e77584fa2d8253ce5d8bea519eb3ffd4.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h). It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.
Include qemu/main-loop.h only where it's needed. Touching it now
recompiles only some 1700 objects. For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the
others, they shrink only slightly.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
All these functions use the v9fs_co_run_in_worker() macro, and thus always
call qemu_coroutine_self() and qemu_coroutine_yield().
Let's mark them to make it obvious they execute in coroutine context.
Signed-off-by: Greg Kurz <groug@kaod.org>
This patch changes the 9p code to use readdir() again instead of
readdir_r(), which is deprecated in glibc 2.24.
All the locking was put in place by a previous patch.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Most of the 9p code is now virtio agnostic. This patch does a final cleanup:
- drop references to Virtio from the header comments
- fix includes
Also drop a couple of leading empty lines while here.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-18-git-send-email-peter.maydell@linaro.org
Those two files are not virtio specific. Rename them to use generic
names.
Fix includes in various C files. Change define guards and comments in
header files.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
The coroutine files are currently referenced by the block-obj-y
variable. The coroutine functionality though is already used by
more than just the block code. eg migration code uses coroutine
yield. In the future the I/O channel code will also use the
coroutine yield functionality. Since the coroutine code is nicely
self-contained it can be easily built as part of the libqemuutil.a
library, making it widely available.
The headers are also moved into include/qemu, instead of the
include/block directory, since they are now part of the util
codebase, and the impl was never in the block/ directory
either.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Double semicolons should be single.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
To implement synthetic file system in Qemu we may not really
require file descriptor and Dir *. Make generic code use
V9fsFidOpenState instead.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Add a new context flag PATHNAME_FSCONTEXT and indicate whether
the fs driver track fid using path names. Also add a private
pointer that help us to track fs driver specific values in there
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This enables us to add handles to track fids later. The
V9fsPath added is similar to V9fsString except that the
size include the NULL byte also.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
On rename we take the write lock and this ensure path
doesn't change as we operate on them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
