mirror of
https://github.com/Motorhead1991/qemu.git
synced 2026-01-18 05:45:29 -07:00
84d61e5f36
virtio-blk and virtio-scsi invoke virtio_irqfd_notify() to send Used Buffer Notifications from an IOThread. This involves an eventfd write(2) syscall. Calling this repeatedly when completing multiple I/O requests in a row is wasteful. Use the defer_call() API to batch together virtio_irqfd_notify() calls made during thread pool (aio=threads), Linux AIO (aio=native), and io_uring (aio=io_uring) completion processing. Behavior is unchanged for emulated devices that do not use defer_call_begin()/defer_call_end() since defer_call() immediately invokes the callback when called outside a defer_call_begin()/defer_call_end() region. fio rw=randread bs=4k iodepth=64 numjobs=8 IOPS increases by ~9% with a single IOThread and 8 vCPUs. iodepth=1 decreases by ~1% but this could be noise. Detailed performance data and configuration specifics are available here: https://gitlab.com/stefanha/virt-playbooks/-/tree/blk_io_plug-irqfd This duplicates the BH that virtio-blk uses for batching. The next commit will remove it. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20230913200045.1024233-4-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
||
|---|---|---|
| .. | ||
| aio-posix.c | ||
| aio-posix.h | ||
| aio-wait.c | ||
| aio-win32.c | ||
| aiocb.c | ||
| async.c | ||
| atomic64.c | ||
| base64.c | ||
| bitmap.c | ||
| bitops.c | ||
| block-helpers.c | ||
| block-helpers.h | ||
| buffer.c | ||
| bufferiszero.c | ||
| cacheflush.c | ||
| compatfd.c | ||
| coroutine-sigaltstack.c | ||
| coroutine-ucontext.c | ||
| coroutine-windows.c | ||
| cpuinfo-aarch64.c | ||
| cpuinfo-i386.c | ||
| cpuinfo-ppc.c | ||
| crc-ccitt.c | ||
| crc32c.c | ||
| cutils.c | ||
| dbus.c | ||
| defer-call.c | ||
| drm.c | ||
| envlist.c | ||
| error-report.c | ||
| error.c | ||
| event_notifier-posix.c | ||
| event_notifier-win32.c | ||
| fdmon-epoll.c | ||
| fdmon-io_uring.c | ||
| fdmon-poll.c | ||
| fifo8.c | ||
| filemonitor-inotify.c | ||
| filemonitor-stub.c | ||
| getauxval.c | ||
| guest-random.c | ||
| hbitmap.c | ||
| hexdump.c | ||
| host-utils.c | ||
| id.c | ||
| int128.c | ||
| interval-tree.c | ||
| iov.c | ||
| iova-tree.c | ||
| keyval.c | ||
| lockcnt.c | ||
| log.c | ||
| main-loop.c | ||
| memalign.c | ||
| memfd.c | ||
| meson.build | ||
| mmap-alloc.c | ||
| module.c | ||
| notify.c | ||
| nvdimm-utils.c | ||
| osdep.c | ||
| oslib-posix.c | ||
| oslib-win32.c | ||
| path.c | ||
| qdist.c | ||
| qemu-co-shared-resource.c | ||
| qemu-co-timeout.c | ||
| qemu-config.c | ||
| qemu-coroutine-io.c | ||
| qemu-coroutine-lock.c | ||
| qemu-coroutine-sleep.c | ||
| qemu-coroutine.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 | ||
| qtree.c | ||
| range.c | ||
| rcu.c | ||
| readline.c | ||
| selfmap.c | ||
| stats64.c | ||
| sys_membarrier.c | ||
| systemd.c | ||
| thread-context.c | ||
| thread-pool.c | ||
| throttle.c | ||
| timed-average.c | ||
| trace-events | ||
| trace.h | ||
| transactions.c | ||
| unicode.c | ||
| uri.c | ||
| userfaultfd.c | ||
| uuid.c | ||
| vfio-helpers.c | ||
| vhost-user-server.c | ||
| yank.c | ||