Re: [PATCH v2 1/5] system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()
Am 12. Dezember 2023 15:39:00 UTC schrieb Stefan Hajnoczi : >The Big QEMU Lock (BQL) has many names and they are confusing. The >actual QemuMutex variable is called qemu_global_mutex but it's commonly >referred to as the BQL in discussions and some code comments. The >locking APIs, however, are called qemu_mutex_lock_iothread() and >qemu_mutex_unlock_iothread(). > >The "iothread" name is historic and comes from when the main thread was >split into into KVM vcpu threads and the "iothread" (now called the main Duplicate "into" here. >loop thread). I have contributed to the confusion myself by introducing >a separate --object iothread, a separate concept unrelated to the BQL. > >The "iothread" name is no longer appropriate for the BQL. Rename the >locking APIs to: >- void bql_lock(void) >- void bql_unlock(void) >- bool bql_locked(void) > >There are more APIs with "iothread" in their names. Subsequent patches >will rename them. There are also comments and documentation that will be >updated in later patches. > >Signed-off-by: Stefan Hajnoczi >Reviewed-by: Paul Durrant >Acked-by: Fabiano Rosas >Acked-by: David Woodhouse >Reviewed-by: Cédric Le Goater >Acked-by: Peter Xu >Acked-by: Eric Farman >Reviewed-by: Harsh Prateek Bora
Re: [PATCH v2 1/5] system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()
On Wed, Dec 13, 2023 at 03:37:00PM +0900, Akihiko Odaki wrote: > On 2023/12/13 0:39, Stefan Hajnoczi wrote: > > @@ -312,58 +312,58 @@ bool qemu_in_main_thread(void); > > } while (0) > > /** > > - * qemu_mutex_lock_iothread: Lock the main loop mutex. > > + * bql_lock: Lock the Big QEMU Lock (BQL). > >* > > - * This function locks the main loop mutex. The mutex is taken by > > + * This function locks the Big QEMU Lock (BQL). The lock is taken by > >* main() in vl.c and always taken except while waiting on > > - * external events (such as with select). The mutex should be taken > > + * external events (such as with select). The lock should be taken > >* by threads other than the main loop thread when calling > >* qemu_bh_new(), qemu_set_fd_handler() and basically all other > >* functions documented in this file. > >* > > - * NOTE: tools currently are single-threaded and qemu_mutex_lock_iothread > > + * NOTE: tools currently are single-threaded and bql_lock > >* is a no-op there. > >*/ > > -#define qemu_mutex_lock_iothread() \ > > -qemu_mutex_lock_iothread_impl(__FILE__, __LINE__) > > -void qemu_mutex_lock_iothread_impl(const char *file, int line); > > +#define bql_lock() \ > > +bql_lock_impl(__FILE__, __LINE__) > > This line break is no longer necessary. Will fix in v3. Stefan signature.asc Description: PGP signature
Re: [PATCH v2 1/5] system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()
On 2023/12/13 0:39, Stefan Hajnoczi wrote: The Big QEMU Lock (BQL) has many names and they are confusing. The actual QemuMutex variable is called qemu_global_mutex but it's commonly referred to as the BQL in discussions and some code comments. The locking APIs, however, are called qemu_mutex_lock_iothread() and qemu_mutex_unlock_iothread(). The "iothread" name is historic and comes from when the main thread was split into into KVM vcpu threads and the "iothread" (now called the main loop thread). I have contributed to the confusion myself by introducing a separate --object iothread, a separate concept unrelated to the BQL. The "iothread" name is no longer appropriate for the BQL. Rename the locking APIs to: - void bql_lock(void) - void bql_unlock(void) - bool bql_locked(void) There are more APIs with "iothread" in their names. Subsequent patches will rename them. There are also comments and documentation that will be updated in later patches. Signed-off-by: Stefan Hajnoczi Reviewed-by: Paul Durrant Acked-by: Fabiano Rosas Acked-by: David Woodhouse Reviewed-by: Cédric Le Goater Acked-by: Peter Xu Acked-by: Eric Farman Reviewed-by: Harsh Prateek Bora --- include/block/aio-wait.h | 2 +- include/qemu/main-loop.h | 40 - include/qemu/thread.h| 2 +- accel/accel-blocker.c| 10 +-- accel/dummy-cpus.c | 8 +- accel/hvf/hvf-accel-ops.c| 4 +- accel/kvm/kvm-accel-ops.c| 4 +- accel/kvm/kvm-all.c | 22 ++--- accel/tcg/cpu-exec.c | 26 +++--- accel/tcg/cputlb.c | 16 ++-- accel/tcg/tcg-accel-ops-icount.c | 4 +- accel/tcg/tcg-accel-ops-mttcg.c | 12 +-- accel/tcg/tcg-accel-ops-rr.c | 14 ++-- accel/tcg/tcg-accel-ops.c| 2 +- accel/tcg/translate-all.c| 2 +- cpu-common.c | 4 +- dump/dump.c | 4 +- hw/core/cpu-common.c | 6 +- hw/i386/intel_iommu.c| 6 +- hw/i386/kvm/xen_evtchn.c | 16 ++-- hw/i386/kvm/xen_overlay.c| 2 +- hw/i386/kvm/xen_xenstore.c | 2 +- hw/intc/arm_gicv3_cpuif.c| 2 +- hw/intc/s390_flic.c | 18 ++-- hw/misc/edu.c| 4 +- hw/misc/imx6_src.c | 2 +- hw/misc/imx7_src.c | 2 +- hw/net/xen_nic.c | 8 +- hw/ppc/pegasos2.c| 2 +- hw/ppc/ppc.c | 4 +- hw/ppc/spapr.c | 2 +- hw/ppc/spapr_rng.c | 4 +- hw/ppc/spapr_softmmu.c | 4 +- hw/remote/mpqemu-link.c | 20 ++--- hw/remote/vfio-user-obj.c| 2 +- hw/s390x/s390-skeys.c| 2 +- migration/block-dirty-bitmap.c | 4 +- migration/block.c| 16 ++-- migration/colo.c | 60 +++--- migration/dirtyrate.c| 12 +-- migration/migration.c| 52 ++-- migration/ram.c | 12 +-- replay/replay-internal.c | 2 +- semihosting/console.c| 8 +- stubs/iothread-lock.c| 6 +- system/cpu-throttle.c| 4 +- system/cpus.c| 51 ++-- system/dirtylimit.c | 4 +- system/memory.c | 2 +- system/physmem.c | 8 +- system/runstate.c| 2 +- system/watchpoint.c | 4 +- target/arm/arm-powerctl.c| 14 ++-- target/arm/helper.c | 4 +- target/arm/hvf/hvf.c | 8 +- target/arm/kvm.c | 4 +- target/arm/kvm64.c | 4 +- target/arm/ptw.c | 6 +- target/arm/tcg/helper-a64.c | 8 +- target/arm/tcg/m_helper.c| 6 +- target/arm/tcg/op_helper.c | 24 +++--- target/arm/tcg/psci.c| 2 +- target/hppa/int_helper.c | 8 +- target/i386/hvf/hvf.c| 6 +- target/i386/kvm/hyperv.c | 4 +- target/i386/kvm/kvm.c| 28 +++ target/i386/kvm/xen-emu.c| 14 ++-- target/i386/nvmm/nvmm-accel-ops.c| 4 +- target/i386/nvmm/nvmm-all.c | 20 ++--- target/i386/tcg/sysemu/fpu_helper.c | 6 +- target/i386/tcg/sysemu/misc_helper.c | 4 +- target/i386/whpx/whpx-accel-ops.c| 4 +- target/i386/whpx/whpx-all.c | 24 +++--- target/loongarch/csr_helper.c| 4 +- target/mips/kvm.c| 4 +- target/mips/tcg/sysemu/cp0_helper.c | 4 +- target/openrisc/sys_helper.c | 16 ++-- target/ppc/excp_helper.c
[PATCH v2 1/5] system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()
The Big QEMU Lock (BQL) has many names and they are confusing. The actual QemuMutex variable is called qemu_global_mutex but it's commonly referred to as the BQL in discussions and some code comments. The locking APIs, however, are called qemu_mutex_lock_iothread() and qemu_mutex_unlock_iothread(). The "iothread" name is historic and comes from when the main thread was split into into KVM vcpu threads and the "iothread" (now called the main loop thread). I have contributed to the confusion myself by introducing a separate --object iothread, a separate concept unrelated to the BQL. The "iothread" name is no longer appropriate for the BQL. Rename the locking APIs to: - void bql_lock(void) - void bql_unlock(void) - bool bql_locked(void) There are more APIs with "iothread" in their names. Subsequent patches will rename them. There are also comments and documentation that will be updated in later patches. Signed-off-by: Stefan Hajnoczi Reviewed-by: Paul Durrant Acked-by: Fabiano Rosas Acked-by: David Woodhouse Reviewed-by: Cédric Le Goater Acked-by: Peter Xu Acked-by: Eric Farman Reviewed-by: Harsh Prateek Bora --- include/block/aio-wait.h | 2 +- include/qemu/main-loop.h | 40 - include/qemu/thread.h| 2 +- accel/accel-blocker.c| 10 +-- accel/dummy-cpus.c | 8 +- accel/hvf/hvf-accel-ops.c| 4 +- accel/kvm/kvm-accel-ops.c| 4 +- accel/kvm/kvm-all.c | 22 ++--- accel/tcg/cpu-exec.c | 26 +++--- accel/tcg/cputlb.c | 16 ++-- accel/tcg/tcg-accel-ops-icount.c | 4 +- accel/tcg/tcg-accel-ops-mttcg.c | 12 +-- accel/tcg/tcg-accel-ops-rr.c | 14 ++-- accel/tcg/tcg-accel-ops.c| 2 +- accel/tcg/translate-all.c| 2 +- cpu-common.c | 4 +- dump/dump.c | 4 +- hw/core/cpu-common.c | 6 +- hw/i386/intel_iommu.c| 6 +- hw/i386/kvm/xen_evtchn.c | 16 ++-- hw/i386/kvm/xen_overlay.c| 2 +- hw/i386/kvm/xen_xenstore.c | 2 +- hw/intc/arm_gicv3_cpuif.c| 2 +- hw/intc/s390_flic.c | 18 ++-- hw/misc/edu.c| 4 +- hw/misc/imx6_src.c | 2 +- hw/misc/imx7_src.c | 2 +- hw/net/xen_nic.c | 8 +- hw/ppc/pegasos2.c| 2 +- hw/ppc/ppc.c | 4 +- hw/ppc/spapr.c | 2 +- hw/ppc/spapr_rng.c | 4 +- hw/ppc/spapr_softmmu.c | 4 +- hw/remote/mpqemu-link.c | 20 ++--- hw/remote/vfio-user-obj.c| 2 +- hw/s390x/s390-skeys.c| 2 +- migration/block-dirty-bitmap.c | 4 +- migration/block.c| 16 ++-- migration/colo.c | 60 +++--- migration/dirtyrate.c| 12 +-- migration/migration.c| 52 ++-- migration/ram.c | 12 +-- replay/replay-internal.c | 2 +- semihosting/console.c| 8 +- stubs/iothread-lock.c| 6 +- system/cpu-throttle.c| 4 +- system/cpus.c| 51 ++-- system/dirtylimit.c | 4 +- system/memory.c | 2 +- system/physmem.c | 8 +- system/runstate.c| 2 +- system/watchpoint.c | 4 +- target/arm/arm-powerctl.c| 14 ++-- target/arm/helper.c | 4 +- target/arm/hvf/hvf.c | 8 +- target/arm/kvm.c | 4 +- target/arm/kvm64.c | 4 +- target/arm/ptw.c | 6 +- target/arm/tcg/helper-a64.c | 8 +- target/arm/tcg/m_helper.c| 6 +- target/arm/tcg/op_helper.c | 24 +++--- target/arm/tcg/psci.c| 2 +- target/hppa/int_helper.c | 8 +- target/i386/hvf/hvf.c| 6 +- target/i386/kvm/hyperv.c | 4 +- target/i386/kvm/kvm.c| 28 +++ target/i386/kvm/xen-emu.c| 14 ++-- target/i386/nvmm/nvmm-accel-ops.c| 4 +- target/i386/nvmm/nvmm-all.c | 20 ++--- target/i386/tcg/sysemu/fpu_helper.c | 6 +- target/i386/tcg/sysemu/misc_helper.c | 4 +- target/i386/whpx/whpx-accel-ops.c| 4 +- target/i386/whpx/whpx-all.c | 24 +++--- target/loongarch/csr_helper.c| 4 +- target/mips/kvm.c| 4 +- target/mips/tcg/sysemu/cp0_helper.c | 4 +- target/openrisc/sys_helper.c | 16 ++-- target/ppc/excp_helper.c | 12 +-- target/ppc/kvm.c | 4 +- target/ppc/misc_helper.c | 8 +-
