qemu/docs
Paolo Bonzini 05e514b1d4 AioContext: optimize clearing the EventNotifier
It is pretty rare for aio_notify to actually set the EventNotifier.  It
can happen with worker threads such as thread-pool.c's, but otherwise it
should never be set thanks to the ctx->notify_me optimization.  The
previous patch, unfortunately, added an unconditional call to
event_notifier_test_and_clear; now add a userspace fast path that
avoids the call.

Note that it is not possible to do the same with event_notifier_set;
it would break, as proved (again) by the included formal model.

This patch survived over 3000 reboots on aarch64 KVM.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Message-id: 1437487673-23740-7-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-07-22 12:41:40 +01:00
..
qmp migration: create migration event 2015-07-07 14:54:55 +02:00
specs Revert "vhost-user: add multi queue support" 2015-07-20 14:19:40 +03:00
aio_notify_accept.promela AioContext: optimize clearing the EventNotifier 2015-07-22 12:41:40 +01:00
aio_notify_bug.promela AioContext: fix broken placement of event_notifier_test_and_clear 2015-07-22 12:41:40 +01:00
aio_notify.promela AioContext: fix broken ctx->dispatching optimization 2015-07-22 12:41:40 +01:00
atomics.txt docs/atomics.txt: fix two typos 2015-04-30 16:05:48 +03:00
bitmaps.md qapi: Rename 'dirty-bitmap' mode to 'incremental' 2015-07-02 09:20:18 +01:00
blkdebug.txt block: Rename BlockDriverCompletionFunc to BlockCompletionFunc 2014-10-20 13:41:27 +02:00
blkverify.txt blkverify: Add block driver for verifying I/O 2010-09-21 17:00:53 +02:00
bootindex.txt Typo, spelling and grammatical fixes 2013-04-12 14:33:20 +02:00
ccid.txt libcacard: improve documentation 2014-06-10 07:44:01 +02:00
ich9-ehci-uhci.cfg usb: update documentation 2011-07-08 11:25:56 +02:00
image-fuzzer.txt docs: List all image elements currently supported by the fuzzer 2014-09-22 11:39:35 +01:00
libcacard.txt libcacard: Spelling and grammar fixes in documentation 2012-03-08 15:22:11 +00:00
live-block-ops.txt docs: describe live block operations 2012-01-26 14:49:18 +01:00
memory-hotplug.txt docs: update documentation for memory hot unplug 2015-04-27 21:07:38 +02:00
memory.txt docs: clarify memory region lifecycle 2015-02-16 17:30:19 +01:00
migration.txt migration: Use normal VMStateDescriptions for Subsections 2015-06-12 06:53:57 +02:00
multi-thread-compression.txt docs: Add a doc about multiple thread compression 2015-05-06 17:36:57 +02:00
multiple-iothreads.txt docs/multiple-iothreads.txt: add documentation on IOThread programming 2014-08-15 15:07:13 +02:00
multiseat.txt update pci-bridge-seat section in docs/multiseat.txt 2015-07-03 12:21:11 +02:00
pci_expander_bridge.txt docs: Add PXB documentation 2015-06-03 18:19:19 +02:00
q35-chipset.cfg q35: Add PCIe switch to example q35 configuration 2013-08-21 12:39:15 +03:00
qapi-code-gen.txt qapi: Drop bogus command from docs 2015-06-18 14:12:33 +02:00
qdev-device-use.txt docs: Fix qdev-device-use.txt typo in -chardev serial, path=COM<NUM> 2011-09-09 09:43:17 +01:00
qemupciserial.inf Docs: Introduce multiport serial support in qemupciserial.inf. 2014-03-12 10:33:23 +01:00
rcu.txt rcu: add g_free_rcu 2015-02-16 17:30:19 +01:00
rdma.txt rdma: Fix incorrect description in comments 2014-09-20 17:55:53 +04:00
spice-port-fqdn.txt docs: add spice-port-fqdn.txt 2012-12-17 14:01:41 +01:00
tracing.txt Tracing docs fix configure option and description 2014-11-18 14:05:54 +00:00
usb2.txt usb: update docs for bus name change 2013-04-03 11:39:43 +02:00
usb-storage.txt Fix typos and misspellings 2013-03-22 13:25:07 +01:00
virtio-balloon-stats.txt virtio-balloon: return empty data when no stats are available 2014-05-25 12:46:58 +03:00
vnc-ledstate-Pseudo-encoding.txt doc: document the Pseudo-encoding of LED state 2013-04-29 08:28:51 -05:00
writing-qmp-commands.txt docs/writing-qmp-commands: fix a typo 2015-06-03 14:21:23 +03:00
xbzrle.txt xbzrle: optimize XBZRLE to decrease the cache misses 2015-01-15 17:49:43 +05:30
xen-save-devices-state.txt Introduce "xen-save-devices-state" 2012-03-19 18:21:00 +00:00