qemu/util
Paolo Bonzini 993ed89f35 aio-posix: ensure poll mode is left when aio_notify is called
With aio=thread, adaptive polling makes latency worse rather than
better, because it delays the execution of the ThreadPool's
completion bottom half.

event_notifier_poll() does run while polling, detecting that
a bottom half was scheduled by a worker thread, but because
ctx->notifier is explicitly ignored in run_poll_handlers_once(),
scheduling the BH does not count as making progress and
run_poll_handlers() keeps running.  Fix this by recomputing
the deadline after *timeout could have changed.

With this change, ThreadPool still cannot participate in polling
but at least it does not suffer from extra latency.

Reported-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20190409122823.12416-1-pbonzini@redhat.com
Cc: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1553692145-86728-1-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20190409122823.12416-1-pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-05-10 10:53:21 +01:00
..
Makefile.objs
aio-posix.c aio-posix: ensure poll mode is left when aio_notify is called 2019-05-10 10:53:21 +01:00
aio-wait.c
aio-win32.c
aiocb.c
async.c
atomic64.c
base64.c
bitmap.c
bitops.c
buffer.c
bufferiszero.c
cacheinfo.c
compatfd.c
coroutine-sigaltstack.c
coroutine-ucontext.c
coroutine-win32.c
crc32c.c
cutils.c
drm.c
envlist.c
error.c
event_notifier-posix.c
event_notifier-win32.c
fifo8.c
filemonitor-inotify.c
filemonitor-stub.c
getauxval.c
hbitmap.c
hexdump.c
host-utils.c
id.c
iohandler.c
iov.c
iova-tree.c
keyval.c
lockcnt.c
log.c
main-loop.c
memfd.c
mmap-alloc.c
module.c
notify.c
osdep.c
oslib-posix.c
oslib-win32.c
pagesize.c
path.c
qdist.c
qemu-config.c
qemu-coroutine-io.c
qemu-coroutine-lock.c
qemu-coroutine-sleep.c
qemu-coroutine.c
qemu-error.c
qemu-openpty.c
qemu-option.c
qemu-print.c
qemu-progress.c
qemu-sockets.c
qemu-thread-common.h
qemu-thread-posix.c
qemu-thread-win32.c
qemu-timer-common.c
qemu-timer.c
qht.c
qsp.c
range.c
rcu.c
readline.c
stats64.c
sys_membarrier.c
systemd.c
thread-pool.c
throttle.c
timed-average.c
trace-events
unicode.c
uri.c
uuid.c
vfio-helpers.c