This patch adds a ThreadPool to AioContext. It's possible that some
AioContext instances will never use the ThreadPool, so defer creation
until aio_get_thread_pool().
The reason why AioContext should have the ThreadPool is because the
ThreadPool is bound to a AioContext instance where the work item's
callback function is invoked. It doesn't make sense to keep the
ThreadPool pointer anywhere other than AioContext. For example,
block/raw-posix.c can get its AioContext's ThreadPool and submit work.
Special note about headers: I used struct ThreadPool in aio.h because
there is a circular dependency if aio.h includes thread-pool.h.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
AioHandler already has a GPollFD so we can directly use its
events/revents.
Add the int pollfds_idx field to AioContext so we can map g_poll(3)
results back to AioHandlers.
Reuse aio_dispatch() to invoke handlers after g_poll(3).
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1361356113-11049-10-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Commit ed2aec4867f0d5f5de496bb765347b5d0cfe113d changed the return
value of aio_ctx_prepare from false to true when only idle bottom
halves are available. This broke PC old-style DMA, which uses them.
Fix this by making aio_ctx_prepare return true only when non-idle
bottom halves are scheduled to run.
Reported-by: malc <av1474@comtv.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: malc <av1474@comtv.ru>
Some cleanups can now be made, now that the main loop does not anymore need
hooks into the bottom half code.
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With this change async.c does not rely anymore on any service from
main-loop.c, i.e. it is completely self-contained.
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This will be used when polling the GSource attached to an AioContext.
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With this patch, I/O handlers (including event notifier handlers) can be
attached to a single AioContext.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Start introducing AioContext, which will let us remove globals from
aio.c/async.c, and introduce multiple I/O threads.
The bottom half functions now take an additional AioContext argument.
A bottom half is created with a specific AioContext that remains the
same throughout the lifetime. qemu_bh_new is just a wrapper that
uses a global context.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using bool reduces the size of the structure and improves readability.
A hole in the structure was removed.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
- remove qemu_calculate_timeout;
- explicitly size timeout to uint32_t;
- introduce slirp_update_timeout;
- pass NULL as timeout argument to select in case timeout is the maximum
value;
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Paul Brook <paul@codesourcery.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
qemu may segfault when a BH handler first deletes a BH and then (possibly
indirectly) calls a nested qemu_bh_poll(). This is because the inner instance
frees the BH and deletes it from the list that the outer one processes.
This patch deletes BHs only in the outermost qemu_bh_poll instance.
Commit 7887f620 already tried to achieve the same, but it assumed that the BH
handler would only delete its own BH. With a nested qemu_bh_poll(), this isn't
guaranteed, so that commit wasn't enough. Hope this one fixes it for real.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The purpose of AsyncContexts was to protect qcow and qcow2 against reentrancy
during an emulated bdrv_read/write (which includes a qemu_aio_wait() call and
can run AIO callbacks of different requests if it weren't for AsyncContexts).
Now both qcow and qcow2 are protected by CoMutexes and AsyncContexts can be
removed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Without this, qemu segfaults when a BH handler first deletes its BH and
then calls another function which involves a nested qemu_bh_poll() call.
This can be reproduced by generating an I/O error (e.g. with blkdebug) on
an IDE device and using rerror/werror=stop to stop the VM. When continuing
the VM, qemu segfaults.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Add the possibility to use AIO and BHs without allowing foreign callbacks to be
run. Basically, you put your own AIOs and BHs in a separate context. For
details see the comments in the source.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Instead of putting more and more stuff into vl.c, let's have the generic
functions that deal with asynchronous callbacks in their own file.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
