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2024-12-20qemu/coroutine: Include missing 'qemu/atomic.h' headerPhilippe Mathieu-Daudé1-0/+1
Commit 944f3d5dd21 ("coroutine: Add qemu_co_mutex_assert_locked") added an inline method which uses qatomic_read(), itself declared in "qemu/atomic.h". Explicitly include it now to avoid issue when refactoring unrelated headers. Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Message-Id: <20241217141326.98947-3-philmd@linaro.org>
2024-05-03lockable: remove QemuLockable from typedefs.hPaolo Bonzini1-2/+2
Using QemuLockable almost always requires going through QEMU_MAKE_LOCKABLE(). Therefore, there is little point in having the typedef always present. Move it to lockable.h, with only a small adjustment to coroutine.h (which has a tricky co-dependency with lockable.h due to defining CoMutex *and* using QemuLockable as a part of the CoQueue API). Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-01-08Rename "QEMU global mutex" to "BQL" in comments and docsStefan Hajnoczi1-1/+1
The term "QEMU global mutex" is identical to the more widely used Big QEMU Lock ("BQL"). Update the code comments and documentation to use "BQL" instead of "QEMU global mutex". Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Paul Durrant <paul@xen.org> Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com> Reviewed-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com> Message-id: 20240102153529.486531-6-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-01-20coroutine: Split qemu/coroutine-core.h off qemu/coroutine.hMarkus Armbruster1-96/+1
qemu/coroutine.h and qemu/lockable.h include each other. They need each other only in macro expansions, so we could simply drop both inclusions to break the loop, and add suitable includes to files that expand the macros. Instead, move a part of qemu/coroutine.h to new qemu/coroutine-core.h so that qemu/coroutine-core.h doesn't need qemu/lockable.h, and qemu/lockable.h only needs qemu/coroutine-core.h. Result: qemu/coroutine.h includes qemu/lockable.h includes qemu/coroutine-core.h. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221221131435.3851212-5-armbru@redhat.com> [Semantic rebase conflict with 7c10cb38cc "accel/tcg: Add debuginfo support" resolved]
2023-01-19coroutine: Move coroutine_fn to qemu/osdep.h, trim includesMarkus Armbruster1-11/+7
block/block-hmp-cmds.h and qemu/co-shared-resource.h use coroutine_fn without including qemu/coroutine.h. They compile only if it's already included from elsewhere. I could fix that, but pulling in qemu/coroutine.h and everything it includes just for a macro that expands into nothing feels silly. Instead, move the macro to qemu/osdep.h. Inclusions of qemu/coroutine.h just for coroutine_fn become superfluous. Drop them. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20221221131435.3851212-3-armbru@redhat.com>
2022-10-30Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into stagingStefan Hajnoczi1-8/+10
Block layer patches - Cleanup bs->backing and bs->file handling - Refactor bdrv_try_set_aio_context using transactions - Changes for improved coroutine_fn consistency - vhost-user-blk: fix the resize crash - io_uring: Use of io_uring_register_ring_fd() led to breakage, revert - vvfat: Fix some problems with r/w mode - Code cleanup - MAINTAINERS: Fold "Block QAPI, monitor, ..." into "Block layer core" # -----BEGIN PGP SIGNATURE----- # # iQJFBAABCAAvFiEE3D3rFZqa+V09dFb+fwmycsiPL9YFAmNazhIRHGt3b2xmQHJl # ZGhhdC5jb20ACgkQfwmycsiPL9ZyTw/8Dfck/SuxfyeLlnQItkjaV4cnqWOU8vHs # 9x0KhlptCs+HXdF/3iicpA0lHojn7mNnbdFGjPRY4E0LriQv91TQ5ycdEmrseFPf # sgeQlgdKCVU/pHjZ2wYarm2pE43Cx85a5xuufmw+7w49dNNZn14l4t+DgviuClVM # nuVaogfZFbYyetre+Qd2TgLl+gJ+0d4o7Zs5lSWLrT8t0L9AGkcWPA7Nrbl6loIE # dOautV4G7jLjuMiCeJZOGcnuRVe3gCQ5rCGBFzzH4DUtz4BmiYx4hd3LMEsP0PMM # CrsfDZS04Ztybl9M7TmJuwkAm1gx1JDMOuJuh18lbJocIOBvhkKKxY2wI5LIdZVI # ZntmU36RowkX+GGu/PYpYyMjBDClJppZCl7vnjyLYsVt6r0Vu6SmlHpJhcRYabhe # 96Kv1LXH9A6+ogKPU3Layw6JGjg01GNr1ALuT7PO3pGto/JshmOuBEJJDucoF84M # 5AfxFCohMROVldwblA6M0eKnlQBgtr5BvtgbV54BBo88VlFJgDJFQn7R09cTFUEo # UwaJoS+nIaiZ0bQQVZhZloVppUaTdVJojzfVRCZZctga96/tu1HSFnGLnbEFpUN3 # KOf+XnVNS6Ro+nPSDf9bMjbIom2JicGFfV+6yMgIoxY/d5UA2dTZfefil4TAlSod # 6PsTgg+jrm8= # =/Fw0 # -----END PGP SIGNATURE----- # gpg: Signature made Thu 27 Oct 2022 14:29:38 EDT # gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6 # gpg: issuer "kwolf@redhat.com" # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full] # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (58 commits) block/block-backend: blk_set_enable_write_cache is IO_CODE monitor: switch to *_co_* functions vmdk: switch to *_co_* functions vhdx: switch to *_co_* functions vdi: switch to *_co_* functions qed: switch to *_co_* functions qcow2: switch to *_co_* functions qcow: switch to *_co_* functions parallels: switch to *_co_* functions mirror: switch to *_co_* functions block: switch to *_co_* functions commit: switch to *_co_* functions vmdk: manually add more coroutine_fn annotations qcow2: manually add more coroutine_fn annotations qcow: manually add more coroutine_fn annotations blkdebug: add missing coroutine_fn annotation for indirect-called functions qcow2: add coroutine_fn annotation for indirect-called functions block: add missing coroutine_fn annotation to BlockDriverState callbacks coroutine-io: add missing coroutine_fn annotation to prototypes coroutine-lock: add missing coroutine_fn annotation to prototypes ... Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-27coroutine-io: add missing coroutine_fn annotation to prototypesAlberto Faria1-3/+5
Signed-off-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221013123711.620631-8-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27coroutine-lock: add missing coroutine_fn annotation to prototypesAlberto Faria1-5/+5
The functions are marked coroutine_fn in the definition. Signed-off-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221013123711.620631-7-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-26coroutine: add flag to re-queue at front of CoQueueStefan Hajnoczi1-2/+13
When a coroutine wakes up it may determine that it must re-queue. Normally coroutines are pushed onto the back of the CoQueue, but for fairness it may be necessary to push it onto the front of the CoQueue. Add a flag to specify that the coroutine should be pushed onto the front of the CoQueue. A later patch will use this to ensure fairness in the bounce buffer CoQueue used by the blkio BlockDriver. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20221013185908.1297568-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-07coroutine: remove incorrect coroutine_fn annotationsPaolo Bonzini1-1/+1
qemu_coroutine_get_aio_context inspects a coroutine, but it does not have to be called from the coroutine itself (or from any coroutine). Reviewed-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220922084924.201610-6-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07coroutine: Drop coroutine_fn annotation from qemu_coroutine_self()Alberto Faria1-1/+1
qemu_coroutine_self() can be called from outside coroutine context, returning the leader coroutine, and several such invocations currently exist (mostly in qcow2 tracing calls). Signed-off-by: Alberto Faria <afaria@redhat.com> Message-Id: <20221005175209.975797-1-afaria@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-06-29util: add qemu-co-timeoutVladimir Sementsov-Ogievskiy1-0/+13
Add new API, to make a time limited call of the coroutine. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
2022-05-12Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into stagingRichard Henderson1-6/+21
* small cleanups for pc-bios/optionrom Makefiles * checkpatch: fix g_malloc check * fix mremap() and RDMA detection * confine igd-passthrough-isa-bridge to Xen-enabled builds * cover PCI in arm-virt machine qtests * add -M boot and -M mem compound properties * bump SLIRP submodule * support CFI with system libslirp (>= 4.7) * clean up CoQueue wakeup functions * fix vhost-vsock regression * fix --disable-vnc compilation * other minor bugfixes # -----BEGIN PGP SIGNATURE----- # # iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmJ8/KMUHHBib256aW5p # QHJlZGhhdC5jb20ACgkQv/vSX3jHroNTTAf9Et1C8iZn+OlZi99wMEeMy8a4mIE5 # CpkBpFphhkBvt3AH7XNsCyL4Gea4QgsI7nOIEVUwvW7gPf85PiBUX8mjrIVg3x1k # bmMEwMKSTYPmDieAnYBP9zCqZQXNYP8L8WxVs2jFY2GXZ2ZogODYFbvCY4yEEB72 # UR6uIvQRdpiB6BEj8UZ+5i+sDtb0zxqrjzUz8T/PJC9/2JSNgi+sAWWQoQT3PPU7 # R7z2nmEa1VeVLPP6mUHvJKhBltVXF+LyIjQHvo+Tp9tSqp9JwXfFBNQ5W/MFes2D # skF47N7PdgKRH9Dp4r0j+MqBwoAq86+ao+MKsbQ1Gb91HhoCWt/MrVrVyg== # =1E6P # -----END PGP SIGNATURE----- # gpg: Signature made Thu 12 May 2022 05:25:07 AM PDT # gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83 # gpg: issuer "pbonzini@redhat.com" # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [undefined] # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [undefined] # gpg: WARNING: This key is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * tag 'for-upstream' of https://gitlab.com/bonzini/qemu: (27 commits) vmxcap: add tertiary execution controls vl: make machine type deprecation a warning meson: link libpng independent of vnc vhost-backend: do not depend on CONFIG_VHOST_VSOCK coroutine-lock: qemu_co_queue_restart_all is a coroutine-only qemu_co_enter_all coroutine-lock: introduce qemu_co_queue_enter_all coroutine-lock: qemu_co_queue_next is a coroutine-only qemu_co_enter_next net: slirp: allow CFI with libslirp >= 4.7 net: slirp: add support for CFI-friendly timer API net: slirp: switch to slirp_new net: slirp: introduce a wrapper struct for QemuTimer slirp: bump submodule past 4.7 release machine: move more memory validation to Machine object machine: make memory-backend a link property machine: add mem compound property machine: add boot compound property machine: use QAPI struct for boot configuration tests/qtest/libqos: Add generic pci host bridge in arm-virt machine tests/qtest/libqos: Skip hotplug tests if pci root bus is not hotpluggable tests/qtest/libqos/pci: Introduce pio_limit ... Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-05-12coroutine-lock: qemu_co_queue_restart_all is a coroutine-only qemu_co_enter_allPaolo Bonzini1-3/+4
qemu_co_queue_restart_all is basically the same as qemu_co_enter_all but without a QemuLockable argument. That's perfectly fine, but only as long as the function is marked coroutine_fn. If used outside coroutine context, qemu_co_queue_wait will attempt to take the lock and that is just broken: if you are calling qemu_co_queue_restart_all outside coroutine context, the lock is going to be a QemuMutex which cannot be taken twice by the same thread. The patch adds the marker to qemu_co_queue_restart_all and to its sole non-coroutine_fn caller; it then reimplements the function in terms of qemu_co_enter_all_impl, to remove duplicated code and to clarify that the latter also works in coroutine context. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20220427130830.150180-4-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-12coroutine-lock: introduce qemu_co_queue_enter_allPaolo Bonzini1-0/+13
Because qemu_co_queue_restart_all does not release the lock, it should be used only in coroutine context. Introduce a new function that, like qemu_co_enter_next, does release the lock, and use it whenever qemu_co_queue_restart_all was used outside coroutine context. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20220427130830.150180-3-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-12coroutine-lock: qemu_co_queue_next is a coroutine-only qemu_co_enter_nextPaolo Bonzini1-3/+4
qemu_co_queue_next is basically the same as qemu_co_enter_next but without a QemuLockable argument. That's perfectly fine, but only as long as the function is marked coroutine_fn. If used outside coroutine context, qemu_co_queue_wait will attempt to take the lock and that is just broken: if you are calling qemu_co_queue_next outside coroutine context, the lock is going to be a QemuMutex which cannot be taken twice by the same thread. The patch adds the marker and reimplements qemu_co_queue_next in terms of qemu_co_enter_next_impl, to remove duplicated code and to clarify that the latter also works in coroutine context. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20220427130830.150180-2-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-12coroutine: Rename qemu_coroutine_inc/dec_pool_size()Kevin Wolf1-3/+3
It's true that these functions currently affect the batch size in which coroutines are reused (i.e. moved from the global release pool to the allocation pool of a specific thread), but this is a bug and will be fixed in a separate patch. In fact, the comment in the header file already just promises that it influences the pool size, so reflect this in the name of the functions. As a nice side effect, the shorter function name makes some line wrapping unnecessary. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20220510151020.105528-2-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-04-06include: move coroutine IO functions to coroutine.hMarc-André Lureau1-0/+23
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20220323155743.1585078-20-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-14util: adjust coroutine pool size to virtio block queueHiroki Narukawa1-0/+10
Coroutine pool size was 64 from long ago, and the basis was organized in the commit message in 4d68e86b. At that time, virtio-blk queue-size and num-queue were not configuable, and equivalent values were 128 and 1. Coroutine pool size 64 was fine then. Later queue-size and num-queue got configuable, and default values were increased. Coroutine pool with size 64 exhausts frequently with random disk IO in new size, and slows down. This commit adjusts coroutine pool size adaptively with new values. This commit adds 64 by default, but now coroutine is not only for block devices, and is not too much burdon comparing with new default. pool size of 128 * vCPUs. Signed-off-by: Hiroki Narukawa <hnarukaw@yahoo-corp.jp> Message-id: 20220214115302.13294-2-hnarukaw@yahoo-corp.jp Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-06-18co-queue: drop extra coroutine_fn marksVladimir Sementsov-Ogievskiy1-2/+4
qemu_co_queue_next() and qemu_co_queue_restart_all() just call aio_co_wake() which works well in non-coroutine context. So these functions can be called from non-coroutine context as well. And actually qemu_co_queue_restart_all() is called from nbd_cancel_in_flight(), which is called from non-coroutine context. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610100802.5888-2-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-05-21coroutine-sleep: introduce qemu_co_sleepPaolo Bonzini1-0/+5
Allow using QemuCoSleep to sleep forever until woken by qemu_co_sleep_wake. This makes the logic of qemu_co_sleep_ns_wakeable easy to understand. In the future we will introduce an API that can work even if the sleep and wake happen from different threads. For now, initializing w->to_wake after timer_mod is fine because the timer can only fire in the same AioContext. Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20210517100548.28806-7-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-05-21coroutine-sleep: replace QemuCoSleepState pointer with struct in the APIPaolo Bonzini1-11/+12
Right now, users of qemu_co_sleep_ns_wakeable are simply passing a pointer to QemuCoSleepState by reference to the function. But QemuCoSleepState really is just a Coroutine*; making the content of the struct public is just as efficient and lets us skip the user_state_pointer indirection. Since the usage is changed, take the occasion to rename the struct to QemuCoSleep. Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20210517100548.28806-6-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-05-21coroutine-sleep: disallow NULL QemuCoSleepState** argumentPaolo Bonzini1-2/+3
Simplify the code by removing conditionals. qemu_co_sleep_ns can simply point the argument to an on-stack temporary. Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20210517100548.28806-3-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-03-31coroutine-lock: Reimplement CoRwlock to fix downgrade bugPaolo Bonzini1-7/+10
An invariant of the current rwlock is that if multiple coroutines hold a reader lock, all must be runnable. The unlock implementation relies on this, choosing to wake a single coroutine when the final read lock holder exits the critical section, assuming that it will wake a coroutine attempting to acquire a write lock. The downgrade implementation violates this assumption by creating a read lock owning coroutine that is exclusively runnable - any other coroutines that are waiting to acquire a read lock are *not* made runnable when the write lock holder converts its ownership to read only. More in general, the old implementation had lots of other fairness bugs. The root cause of the bugs was that CoQueue would wake up readers even if there were pending writers, and would wake up writers even if there were readers. In that case, the coroutine would go back to sleep *at the end* of the CoQueue, losing its place at the head of the line. To fix this, keep the queue of waiters explicitly in the CoRwlock instead of using CoQueue, and store for each whether it is a potential reader or a writer. This way, downgrade can look at the first queued coroutines and wake it only if it is a reader, causing all other readers in line to be released in turn. Reported-by: David Edmondson <david.edmondson@oracle.com> Reviewed-by: David Edmondson <david.edmondson@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20210325112941.365238-5-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-09-23qemu/atomic.h: rename atomic_ to qatomic_Stefan Hajnoczi1-1/+1
clang's C11 atomic_fetch_*() functions only take a C11 atomic type pointer argument. QEMU uses direct types (int, etc) and this causes a compiler error when a QEMU code calls these functions in a source file that also included <stdatomic.h> via a system header file: $ CC=clang CXX=clang++ ./configure ... && make ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid) Avoid using atomic_*() names in QEMU's atomic.h since that namespace is used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h and <stdatomic.h> can co-exist. I checked /usr/include on my machine and searched GitHub for existing "qatomic_" users but there seem to be none. This patch was generated using: $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \ sort -u >/tmp/changed_identifiers $ for identifier in $(</tmp/changed_identifiers); do sed -i "s%\<$identifier\>%q$identifier%g" \ $(git grep -I -l "\<$identifier\>") done I manually fixed line-wrap issues and misaligned rST tables. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2019-10-25coroutine: Add qemu_co_mutex_assert_locked()Kevin Wolf1-0/+15
Some functions require that the caller holds a certain CoMutex for them to operate correctly. Add a function so that they can assert the lock is really held. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Tested-by: Michael Weiser <michael.weiser@gmx.de> Reviewed-by: Michael Weiser <michael.weiser@gmx.de> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Max Reitz <mreitz@redhat.com>
2019-10-22qemu-coroutine-sleep: introduce qemu_co_sleep_wakeVladimir Sementsov-Ogievskiy1-2/+21
Introduce a function to gracefully wake a coroutine sleeping in qemu_co_sleep_ns(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20191009084158.15614-2-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2018-09-25block: Add missing locking in bdrv_co_drain_bh_cb()Kevin Wolf1-0/+5
bdrv_do_drained_begin/end() assume that they are called with the AioContext lock of bs held. If we call drain functions from a coroutine with the AioContext lock held, we yield and schedule a BH to move out of coroutine context. This means that the lock for the home context of the coroutine is released and must be re-acquired in the bottom half. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-02-08coroutine-lock: make qemu_co_enter_next thread-safePaolo Bonzini1-6/+13
qemu_co_queue_next does not need to release and re-acquire the mutex, because the queued coroutine does not run immediately. However, this does not hold for qemu_co_enter_next. Now that qemu_co_queue_wait can synchronize (via QemuLockable) with code that is not running in coroutine context, it's important that code using qemu_co_enter_next can easily use a standardized locking idiom. First of all, qemu_co_enter_next must use aio_co_wake to restart the coroutine. Second, the function gains a second argument, a QemuLockable*, and the comments of qemu_co_queue_next and qemu_co_queue_restart_all are adjusted to clarify the difference. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20180203153935.8056-5-pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2018-02-08coroutine-lock: convert CoQueue to use QemuLockablePaolo Bonzini1-1/+5
There are cases in which a queued coroutine must be restarted from non-coroutine context (with qemu_co_enter_next). In this cases, qemu_co_enter_next also needs to be thread-safe, but it cannot use a CoMutex and so cannot qemu_co_queue_wait. Use QemuLockable so that the CoQueue can interchangeably use CoMutex or QemuMutex. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20180203153935.8056-4-pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2018-02-08lockable: add QemuLockablePaolo Bonzini1-2/+2
QemuLockable is a polymorphic lock type that takes an object and knows which function to use for locking and unlocking. The implementation could use C11 _Generic, but since the support is not very widespread I am instead using __builtin_choose_expr and __builtin_types_compatible_p, which are already used by include/qemu/atomic.h. QemuLockable can be used to implement lock guards, or to pass around a lock in such a way that a function can release it and re-acquire it. The next patch will do this for CoQueue. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20180203153935.8056-3-pbonzini@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-12-19coroutine: simplify co_aio_sleep_ns() prototypeStefan Hajnoczi1-5/+1
The AioContext pointer argument to co_aio_sleep_ns() is only used for the sleep timer. It does not affect where the caller coroutine is resumed. Due to changes to coroutine and AIO APIs it is now possible to drop the AioContext pointer argument. This is safe to do since no caller has specific requirements for which AioContext the timer must run in. This patch drops the AioContext pointer argument and renames the function to simplify the API. Reported-by: Paolo Bonzini <pbonzini@redhat.com> Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20171109102652.6360-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-07-17coroutine-lock: add qemu_co_rwlock_downgrade and qemu_co_rwlock_upgradePaolo Bonzini1-0/+18
These functions are more efficient in the presence of contention. qemu_co_rwlock_downgrade also guarantees not to block, which may be useful in some algorithms too. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170629132749.997-3-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-04-11coroutine: Extract qemu_aio_coroutine_enterFam Zheng1-0/+5
It's a variant of qemu_coroutine_enter with an explicit AioContext parameter. Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-02-21coroutine-lock: make CoRwlock thread-safe and fairPaolo Bonzini1-1/+2
This adds a CoMutex around the existing CoQueue. Because the write-side can just take CoMutex, the old "writer" field is not necessary anymore. Instead of removing it altogether, count the number of pending writers during a read-side critical section and forbid further readers from entering. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213181244.16297-7-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21coroutine-lock: add mutex argument to CoQueue APIsPaolo Bonzini1-3/+5
All that CoQueue needs in order to become thread-safe is help from an external mutex. Add this to the API. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213181244.16297-6-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21coroutine-lock: place CoMutex before CoQueue in headerPaolo Bonzini1-45/+44
This will avoid forward references in the next patch. It is also more logical because CoQueue is not anymore the basic primitive. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213181244.16297-5-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21coroutine-lock: add limited spinning to CoMutexPaolo Bonzini1-0/+5
Running a very small critical section on pthread_mutex_t and CoMutex shows that pthread_mutex_t is much faster because it doesn't actually go to sleep. What happens is that the critical section is shorter than the latency of entering the kernel and thus FUTEX_WAIT always fails. With CoMutex there is no such latency but you still want to avoid wait and wakeup. So introduce it artificially. This only works with one waiters; because CoMutex is fair, it will always have more waits and wakeups than a pthread_mutex_t. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213181244.16297-3-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21coroutine-lock: make CoMutex thread-safePaolo Bonzini1-2/+15
This uses the lock-free mutex described in the paper '"Blocking without Locking", or LFTHREADS: A lock-free thread library' by Gidenstam and Papatriantafilou. The same technique is used in OSv, and in fact the code is essentially a conversion to C of OSv's code. [Added missing coroutine_fn in tests/test-aio-multithread.c. --Stefan] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213181244.16297-2-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-09coroutine: Introduce qemu_coroutine_enter_if_inactive()Kevin Wolf1-0/+6
In the context of asynchronous work, if we have a worker coroutine that didn't yield, the parent coroutine cannot be reentered because it hasn't yielded yet. In this case we don't even have to reenter the parent because it will see that the work is already done and won't even yield. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com>
2016-09-28coroutine: add qemu_coroutine_entered() functionStefan Hajnoczi1-0/+13
See the doc comments for a description of this new coroutine API. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1474989516-18255-2-git-send-email-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-05coroutine: Let CoMutex remember who holds itKevin Wolf1-0/+1
In cases of deadlocks, knowing who holds a given CoMutex is really helpful for debugging. Keeping the information around doesn't cost much and allows us to add another assertion to keep the code correct, so let's just add it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-13coroutine: move entry argument to qemu_coroutine_createPaolo Bonzini1-5/+3
In practice the entry argument is always known at creation time, and it is confusing that sometimes qemu_coroutine_enter is used with a non-NULL argument to re-enter a coroutine (this happens in block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value at creation time, for consistency with e.g. aio_bh_new. Mostly done with the following semantic patch: @ entry1 @ expression entry, arg, co; @@ - co = qemu_coroutine_create(entry); + co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry2 @ expression entry, arg; identifier co; @@ - Coroutine *co = qemu_coroutine_create(entry); + Coroutine *co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry3 @ expression entry, arg; @@ - qemu_coroutine_enter(qemu_coroutine_create(entry), arg); + qemu_coroutine_enter(qemu_coroutine_create(entry, arg)); @ reentry @ expression co; @@ - qemu_coroutine_enter(co, NULL); + qemu_coroutine_enter(co); except for the aforementioned few places where the semantic patch stumbled (as expected) and for test_co_queue, which would otherwise produce an uninitialized variable warning. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13coroutine: use QSIMPLEQ instead of QTAILQPaolo Bonzini1-1/+1
CoQueue do not need to remove any element but the head of the list; processing is always strictly FIFO. Therefore, the simpler singly-linked QSIMPLEQ can be used instead. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-22Use scripts/clean-includes to drop redundant qemu/typedefs.hMarkus Armbruster1-1/+0
Re-run scripts/clean-includes to apply the previous commit's corrections and updates. Besides redundant qemu/typedefs.h, this only finds a redundant config-host.h include in ui/egl-helpers.c. No idea how that escaped the previous runs. Some manual whitespace trimming around dropped includes squashed in. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-23include: Clean up includesPeter Maydell1-1/+0
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. NB: If this commit breaks compilation for your out-of-tree patchseries or fork, then you need to make sure you add #include "qemu/osdep.h" to any new .c files that you have. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-10-20coroutine: move into libqemuutil.a libraryDaniel P. Berrange1-0/+219
The coroutine files are currently referenced by the block-obj-y variable. The coroutine functionality though is already used by more than just the block code. eg migration code uses coroutine yield. In the future the I/O channel code will also use the coroutine yield functionality. Since the coroutine code is nicely self-contained it can be easily built as part of the libqemuutil.a library, making it widely available. The headers are also moved into include/qemu, instead of the include/block directory, since they are now part of the util codebase, and the impl was never in the block/ directory either. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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