Commit Graph

11 Commits

Author SHA1 Message Date
Paolo Bonzini 82cbbdc6a0 main-loop: use GSource to poll AIO file descriptors
This lets us remove the hooks for the main loop in async.c.

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30 09:30:53 +01:00
Paolo Bonzini f627aab1cc aio: introduce AioContext, move bottom halves there
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>
2012-10-30 09:30:53 +01:00
Paolo Bonzini 172061a0a0 main-loop: unify qemu_init_main_loop between QEMU and tools
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30 09:18:44 +01:00
Jan Kiszka a7aae221b0 Switch SIG_IPI to SIGUSR1
Use SIGUSR1 unconditionally as SIG_IPI. First, ucontext coroutines tend
to corrupt RT signal masks due to a 32-on-64-bit Linux kernel bug. And,
second, there appears to be no advantage in using RT signals for VCPU
kicking.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 08:33:34 -05:00
Stefano Stabellini 7c7db75576 main_loop_wait: block indefinitely
- 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>
2012-04-26 13:14:58 -05:00
Paolo Bonzini d3385eb448 main-loop: interrupt wait when data arrives on a socket
Right now, the main loop is not interrupted when data arrives on a
socket.  To fix this, register each socket to interrupt the main loop
with WSAEventSelect.  This does not replace select, it only communicates
a change in socket state that requires a select call.

Since the interrupt fires only once per recv call, or only once
after a send call returns EWOULDBLOCK we can activate it on all events
unconditionally.  If QEMU is momentarily uninterested on some condition,
the main loop will not busy wait.  Instead, it may get one extra wakeup,
but then it will ignore the condition until progress occurs and/or
qemu_set_fd_handler is called to set a callback.  At this point the
condition will be tested via select and the callback will be invoked
even if it is still disabled on the event.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-04-07 08:34:16 +00:00
Michael Roth d34e8f6e9d main-loop: For tools, initialize timers as part of qemu_init_main_loop()
In some cases initializing the alarm timers can lead to non-negligable
overhead from programs that link against qemu-tool.o. At least,
setting a max-resolution WinMM alarm timer via mm_start_timer() (the
current default for Windows) can increase the "tick rate" on Windows
OSs and affect frequency scaling, and in the case of tools that run
in guest OSs such has qemu-ga, the impact can be fairly dramatic
(+20%/20% user/sys time on a core 2 processor was observed from an idle
Windows XP guest).

This patch doesn't address the issue directly (not sure what a good
solution would be for Windows, or what other situations it might be
noticeable), but it at least limits the scope of the issue to programs
that "opt-in" to using the main-loop.c functions by only enabling alarm
timers when qemu_init_main_loop() is called, which is already required
to make use of those facilities, so existing users shouldn't be
affected.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-02-01 14:45:02 -06:00
Paolo Bonzini cbcfa0418f link the main loop and its dependencies into the tools
Using the main loop code from QEMU enables tools to operate fully
asynchronously.  Advantages include better Windows portability (for some
definition of portability) over glib's.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22 11:53:58 +01:00
Dong Xu Wang 07f35073c6 fix spelling in main directory
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-12-02 10:50:57 +00:00
Paolo Bonzini d3b12f5dec main-loop: create main-loop.c
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-10-21 18:14:30 +02:00
Paolo Bonzini 44a9b356ad main-loop: create main-loop.h
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-10-21 18:14:30 +02:00