mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
fc8796465c
qemu/util
History
Stefan Hajnoczi fc8796465c aio-posix: fix spurious ->poll_ready() callbacks in main loop 
When ->poll() succeeds the AioHandler is placed on the ready list with
revents set to the magic value 0. This magic value causes
aio_dispatch_handler() to invoke ->poll_ready() instead of ->io_read()
for G_IO_IN or ->io_write() for G_IO_OUT.

This magic value 0 hack works for the IOThread where AioHandlers are
placed on ->ready_list and processed by aio_dispatch_ready_handlers().
It does not work for the main loop where all AioHandlers are processed
by aio_dispatch_handlers(), even those that are not ready and have a
revents value of 0.

As a result the main loop invokes ->poll_ready() on AioHandlers that are
not ready. These spurious ->poll_ready() calls waste CPU cycles and
could lead to crashes if the code assumes ->poll() must have succeeded
before ->poll_ready() is called (a reasonable asumption but I haven't
seen it in practice).

Stop using revents to track whether ->poll_ready() will be called on an
AioHandler. Introduce a separate AioHandler->poll_ready field instead.
This eliminates spurious ->poll_ready() calls in the main loop.

Fixes: 826cc32423 ("aio-posix: split poll check from ready handler")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reported-by: Jason Wang <jasowang@redhat.com>
Tested-by: Jason Wang <jasowang@redhat.com>
Message-id: 20220223155703.136833-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-03-17 11:23:18 +00:00
..
aio-posix.c aio-posix: fix spurious ->poll_ready() callbacks in main loop 2022-03-17 11:23:18 +00:00
aio-posix.h aio-posix: fix spurious ->poll_ready() callbacks in main loop 2022-03-17 11:23:18 +00:00
aio-wait.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
aio-win32.c aio-posix: split poll check from ready handler 2022-01-12 17:09:39 +00:00
aiocb.c
async.c util/async: replace __thread with QEMU TLS macros 2022-03-04 18:14:40 +01:00
atomic64.c osdep: Move memalign-related functions to their own header 2022-03-07 13:16:49 +00:00
base64.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
bitmap.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
bitops.c avoid TABs in files that only contain a few 2019-01-11 15:46:56 +01:00
block-helpers.c block: move logical block size check function to a common utility function 2020-10-23 13:42:16 +01:00
block-helpers.h block: move logical block size check function to a common utility function 2020-10-23 13:42:16 +01:00
buffer.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
bufferiszero.c cpuid: use unsigned for max cpuid 2022-02-04 09:07:43 -05:00
cacheflush.c include: Move qemu_[id]cache_* declarations to new qemu/cacheinfo.h 2022-02-21 13:30:20 +00:00
cacheinfo.c include: Move qemu_[id]cache_* declarations to new qemu/cacheinfo.h 2022-02-21 13:30:20 +00:00
compatfd.c util/compatfd.c: use libc signalfd wrapper instead of raw syscall 2021-10-13 10:47:49 +02:00
coroutine-sigaltstack.c coroutine-sigaltstack: Add SIGUSR2 mutex 2021-01-26 14:36:37 +01:00
coroutine-ucontext.c Remove the CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE switch 2020-07-13 11:40:52 +02:00
coroutine-win32.c
crc32c.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
crc-ccitt.c util: Add CRC16 (CCITT) calculation routines 2021-01-24 20:10:54 +01:00
cutils.c cutils: fix memory leak in get_relocated_path() 2021-05-13 18:06:40 +02:00
dbus.c util: add dbus helper unit 2020-01-06 18:41:32 +04:00
drm.c util/drm: make portable by avoiding struct dirent d_type 2020-07-13 14:36:10 +01:00
envlist.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
error.c error: make Error **errp const where it is appropriate 2019-12-18 08:36:16 +01:00
event_notifier-posix.c event_notifier: add event_notifier_get_wfd() 2022-03-06 06:19:47 -05:00
event_notifier-win32.c
fdmon-epoll.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
fdmon-io_uring.c aio-posix: fix build failure io_uring 2.2 2022-03-17 11:23:18 +00:00
fdmon-poll.c fdmon-poll: reset npfd when upgrading to fdmon-epoll 2020-09-23 13:45:52 +01:00
fifo8.c utils/fifo8: change fatal errors from abort() to assert() 2021-02-07 20:38:20 +00:00
filemonitor-inotify.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
filemonitor-stub.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
getauxval.c util/getauxval: Porting to FreeBSD getauxval feature 2020-06-26 06:45:29 -04:00
guest-random.c util/guest-random: Fix size arg to tail memcpy 2021-07-09 18:42:46 +02:00
hbitmap.c block/dirty-bitmap: introduce bdrv_dirty_bitmap_status() 2022-03-07 09:33:30 +01:00
hexdump.c util/hexdump: introduce qemu_hexdump_line() 2020-09-29 02:14:30 -04:00
host-utils.c host-utils: add 128-bit quotient support to divu128/divs128 2021-10-27 17:10:00 -07:00
id.c net: Use id_generate() in the network subsystem, too 2021-03-09 21:47:45 +01:00
int128.c qemu/int128: addition of div/rem 128-bit operations 2022-01-08 15:46:10 +10:00
iov.c util/iov: make qemu_iovec_init_extended() honest 2021-02-03 08:00:33 -06:00
iova-tree.c util: add iova_tree_find_iova 2022-03-15 13:57:44 +08:00
keyval.c keyval: Fix grammar comment to cover downstream prefix 2022-02-28 11:39:35 +01:00
lockcnt.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
log.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
main-loop.c aio-posix: split poll check from ready handler 2022-01-12 17:09:39 +00:00
memalign.c osdep: Move memalign-related functions to their own header 2022-03-07 13:16:49 +00:00
memfd.c linux-user: add memfd_create 2019-09-11 08:46:17 +02:00
meson.build util: Unify implementations of qemu_memalign() 2022-03-07 13:09:20 +00:00
mmap-alloc.c Deprecate pmem=on with non-DAX capable backend file 2021-07-06 18:05:16 -04:00
module.c modules: check arch on qom lookup 2021-07-09 18:20:27 +02:00
notify.c xen / notify: introduce a new XenWatchList abstraction 2019-09-24 12:18:47 +01:00
nvdimm-utils.c Clean up includes 2020-12-10 17:16:44 +01:00
osdep.c 9pfs: move qemu_dirent_dup() from osdep -> 9p-util 2022-03-07 11:49:31 +01:00
oslib-posix.c util: Put qemu_vfree() in memalign.c 2022-03-07 13:16:24 +00:00
oslib-win32.c util: Put qemu_vfree() in memalign.c 2022-03-07 13:16:24 +00:00
pagesize.c
path.c util/path: Do not cache all filenames at startup 2019-06-24 22:19:30 +02:00
qdist.c
qemu-co-shared-resource.c co-shared-resource: protect with a mutex 2021-06-25 14:24:24 +03:00
qemu-config.c qemu-config: restore "machine" in qmp_query_command_line_options() 2021-07-22 14:44:47 +02:00
qemu-coroutine-io.c aio-posix: split poll check from ready handler 2022-01-12 17:09:39 +00:00
qemu-coroutine-lock.c coroutine-lock: Reimplement CoRwlock to fix downgrade bug 2021-03-31 10:44:21 +01:00
qemu-coroutine-sleep.c coroutine-sleep: introduce qemu_co_sleep 2021-05-21 18:22:33 +01:00
qemu-coroutine.c util: adjust coroutine pool size to virtio block queue 2022-02-14 17:11:25 +00:00
qemu-error.c error: rename error_with_timestamp to message_with_timestamp 2021-02-01 10:50:55 +00:00
qemu-openpty.c util: Remove redundant checks in the openpty() 2021-09-15 14:42:48 +02:00
qemu-option.c qemu-option: Allow deleting opts during qemu_opts_foreach() 2021-10-15 16:11:22 +02:00
qemu-print.c monitor: Use getter/setter functions for cur_mon 2020-10-09 07:08:19 +02:00
qemu-progress.c util/: fix some comment spelling errors 2020-09-17 20:38:42 +02:00
qemu-sockets.c build-sys: add HAVE_IPPROTO_MPTCP 2021-09-30 15:30:25 +02:00
qemu-thread-common.h Clean up includes 2018-12-20 10:29:08 +01:00
qemu-thread-posix.c configure, meson: move pthread_setname_np checks to Meson 2021-10-14 09:50:57 +02:00
qemu-thread-win32.c util: Pass file+line to qemu_rec_mutex_unlock_impl 2021-06-16 15:03:26 +02:00
qemu-timer-common.c semihosting: Implement SYS_ELAPSED and SYS_TICKFREQ 2021-01-18 10:05:06 +00:00
qemu-timer.c spapr: rollback 'unplug timeout' for CPU hotunplugs 2021-04-12 12:27:14 +10:00
qht.c osdep: Move memalign-related functions to their own header 2022-03-07 13:16:49 +00:00
qsp.c qemu/atomic: Add aligned_{int64,uint64}_t types 2021-07-21 07:45:38 -10:00
range.c Don't talk about the LGPL if the file is licensed under the GPL 2019-01-30 10:51:20 +01:00
rcu.c rcu: use coroutine TLS macros 2022-03-04 18:14:40 +01:00
readline.c readline: Fix possible array index out of bounds in readline_hist_add() 2021-01-04 11:13:39 +00:00
selfmap.c util/selfmap: Discard mapping on error 2021-07-26 07:06:49 -10:00
stats64.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
sys_membarrier.c sys_membarrier: fix up include directives 2018-04-05 14:37:38 +02:00
systemd.c tools: Fix use of fcntl(F_SETFD) during socket activation 2020-05-04 14:54:35 -05:00
thread-pool.c lockable: replaced locks with lock guard macros where appropriate 2020-05-04 16:07:43 +01:00
throttle.c Remove superfluous timer_del() calls 2021-01-08 15:13:38 +00:00
timed-average.c
trace-events modules: add tracepoints 2021-07-09 18:20:27 +02:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
transactions.c transactions: Invoke clean() after everything else 2021-11-16 09:43:44 +01:00
unicode.c json: Reject invalid UTF-8 sequences 2018-08-24 20:26:37 +02:00
uri.c util/uri: do not check argument of uri_free() 2021-07-09 12:26:05 +02:00
userfaultfd.c migration: introduce UFFD-WP low-level interface helpers 2021-02-08 11:19:51 +00:00
uuid.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
vfio-helpers.c util/vfio-helpers: Let qemu_vfio_do_mapping() propagate Error 2021-09-07 09:08:24 +01:00
vhost-user-server.c block/export: Fix vhost-user-blk shutdown with requests in flight 2022-02-01 13:49:15 +01:00
yank.c yank: Remove dependency on qiochannel 2021-04-01 15:27:44 +04:00