| Message ID | 20200522160755.886-3-robert.foley@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add Thread Sanitizer support to QEMU | expand |
On 5/22/20 6:07 PM, Robert Foley wrote: > From: "Emilio G. Cota" <cota@braap.org> > > Instead of open-coding it. Please use a full sentence (repeating the patch subject): "Convert queued work to a QSIMPLEQ instead of open-coding it." (Not all email clients display the subject preceding the content). Otherwise: Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> > > While at it, make sure that all accesses to the list are > performed while holding the list's lock. > > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > Signed-off-by: Emilio G. Cota <cota@braap.org> > Signed-off-by: Robert Foley <robert.foley@linaro.org> > --- > cpus-common.c | 25 ++++++++----------------- > cpus.c | 14 ++++++++++++-- > hw/core/cpu.c | 1 + > include/hw/core/cpu.h | 6 +++--- > 4 files changed, 24 insertions(+), 22 deletions(-) > > diff --git a/cpus-common.c b/cpus-common.c > index 55d5df8923..210fc7fc39 100644 > --- a/cpus-common.c > +++ b/cpus-common.c > @@ -97,7 +97,7 @@ void cpu_list_remove(CPUState *cpu) > } > > struct qemu_work_item { > - struct qemu_work_item *next; > + QSIMPLEQ_ENTRY(qemu_work_item) node; > run_on_cpu_func func; > run_on_cpu_data data; > bool free, exclusive, done; > @@ -106,13 +106,7 @@ struct qemu_work_item { > static void queue_work_on_cpu(CPUState *cpu, struct qemu_work_item *wi) > { > qemu_mutex_lock(&cpu->work_mutex); > - if (cpu->queued_work_first == NULL) { > - cpu->queued_work_first = wi; > - } else { > - cpu->queued_work_last->next = wi; > - } > - cpu->queued_work_last = wi; > - wi->next = NULL; > + QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node); > wi->done = false; > qemu_mutex_unlock(&cpu->work_mutex); > > @@ -306,17 +300,14 @@ void process_queued_cpu_work(CPUState *cpu) > { > struct qemu_work_item *wi; > > - if (cpu->queued_work_first == NULL) { > + qemu_mutex_lock(&cpu->work_mutex); > + if (QSIMPLEQ_EMPTY(&cpu->work_list)) { > + qemu_mutex_unlock(&cpu->work_mutex); > return; > } > - > - qemu_mutex_lock(&cpu->work_mutex); > - while (cpu->queued_work_first != NULL) { > - wi = cpu->queued_work_first; > - cpu->queued_work_first = wi->next; > - if (!cpu->queued_work_first) { > - cpu->queued_work_last = NULL; > - } > + while (!QSIMPLEQ_EMPTY(&cpu->work_list)) { > + wi = QSIMPLEQ_FIRST(&cpu->work_list); > + QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node); > qemu_mutex_unlock(&cpu->work_mutex); > if (wi->exclusive) { > /* Running work items outside the BQL avoids the following deadlock: > diff --git a/cpus.c b/cpus.c > index 5670c96bcf..af44027549 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -97,9 +97,19 @@ bool cpu_is_stopped(CPUState *cpu) > return cpu->stopped || !runstate_is_running(); > } > > +static inline bool cpu_work_list_empty(CPUState *cpu) > +{ > + bool ret; > + > + qemu_mutex_lock(&cpu->work_mutex); > + ret = QSIMPLEQ_EMPTY(&cpu->work_list); > + qemu_mutex_unlock(&cpu->work_mutex); > + return ret; > +} > + > static bool cpu_thread_is_idle(CPUState *cpu) > { > - if (cpu->stop || cpu->queued_work_first) { > + if (cpu->stop || !cpu_work_list_empty(cpu)) { > return false; > } > if (cpu_is_stopped(cpu)) { > @@ -1498,7 +1508,7 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg) > cpu = first_cpu; > } > > - while (cpu && !cpu->queued_work_first && !cpu->exit_request) { > + while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) { > > atomic_mb_set(&tcg_current_rr_cpu, cpu); > current_cpu = cpu; > diff --git a/hw/core/cpu.c b/hw/core/cpu.c > index 5284d384fb..77703d62b7 100644 > --- a/hw/core/cpu.c > +++ b/hw/core/cpu.c > @@ -368,6 +368,7 @@ static void cpu_common_initfn(Object *obj) > cpu->nr_threads = 1; > > qemu_mutex_init(&cpu->work_mutex); > + QSIMPLEQ_INIT(&cpu->work_list); > QTAILQ_INIT(&cpu->breakpoints); > QTAILQ_INIT(&cpu->watchpoints); > > diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h > index 07f7698155..d78ff1d165 100644 > --- a/include/hw/core/cpu.h > +++ b/include/hw/core/cpu.h > @@ -331,8 +331,8 @@ struct qemu_work_item; > * @opaque: User data. > * @mem_io_pc: Host Program Counter at which the memory was accessed. > * @kvm_fd: vCPU file descriptor for KVM. > - * @work_mutex: Lock to prevent multiple access to queued_work_*. > - * @queued_work_first: First asynchronous work pending. > + * @work_mutex: Lock to prevent multiple access to @work_list. > + * @work_list: List of pending asynchronous work. > * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes > * to @trace_dstate). > * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask). > @@ -376,7 +376,7 @@ struct CPUState { > sigjmp_buf jmp_env; > > QemuMutex work_mutex; > - struct qemu_work_item *queued_work_first, *queued_work_last; > + QSIMPLEQ_HEAD(, qemu_work_item) work_list; > > CPUAddressSpace *cpu_ases; > int num_ases; >
On Sun, 24 May 2020 at 06:21, Philippe Mathieu-Daudé <philmd@redhat.com> wrote: > > On 5/22/20 6:07 PM, Robert Foley wrote: > > From: "Emilio G. Cota" <cota@braap.org> > > > > Instead of open-coding it. > > Please use a full sentence (repeating the patch subject): > > "Convert queued work to a QSIMPLEQ instead of open-coding it." > > (Not all email clients display the subject preceding the content). OK, I will update this commit message. Thanks & Regards, -Rob > > Otherwise: > Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> > > > > > While at it, make sure that all accesses to the list are > > performed while holding the list's lock. > > > > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > > Signed-off-by: Emilio G. Cota <cota@braap.org> > > Signed-off-by: Robert Foley <robert.foley@linaro.org> > > --- > > cpus-common.c | 25 ++++++++----------------- > > cpus.c | 14 ++++++++++++-- > > hw/core/cpu.c | 1 + > > include/hw/core/cpu.h | 6 +++--- > > 4 files changed, 24 insertions(+), 22 deletions(-) > > > > diff --git a/cpus-common.c b/cpus-common.c > > index 55d5df8923..210fc7fc39 100644 > > --- a/cpus-common.c > > +++ b/cpus-common.c > > @@ -97,7 +97,7 @@ void cpu_list_remove(CPUState *cpu) > > } > > > > struct qemu_work_item { > > - struct qemu_work_item *next; > > + QSIMPLEQ_ENTRY(qemu_work_item) node; > > run_on_cpu_func func; > > run_on_cpu_data data; > > bool free, exclusive, done; > > @@ -106,13 +106,7 @@ struct qemu_work_item { > > static void queue_work_on_cpu(CPUState *cpu, struct qemu_work_item *wi) > > { > > qemu_mutex_lock(&cpu->work_mutex); > > - if (cpu->queued_work_first == NULL) { > > - cpu->queued_work_first = wi; > > - } else { > > - cpu->queued_work_last->next = wi; > > - } > > - cpu->queued_work_last = wi; > > - wi->next = NULL; > > + QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node); > > wi->done = false; > > qemu_mutex_unlock(&cpu->work_mutex); > > > > @@ -306,17 +300,14 @@ void process_queued_cpu_work(CPUState *cpu) > > { > > struct qemu_work_item *wi; > > > > - if (cpu->queued_work_first == NULL) { > > + qemu_mutex_lock(&cpu->work_mutex); > > + if (QSIMPLEQ_EMPTY(&cpu->work_list)) { > > + qemu_mutex_unlock(&cpu->work_mutex); > > return; > > } > > - > > - qemu_mutex_lock(&cpu->work_mutex); > > - while (cpu->queued_work_first != NULL) { > > - wi = cpu->queued_work_first; > > - cpu->queued_work_first = wi->next; > > - if (!cpu->queued_work_first) { > > - cpu->queued_work_last = NULL; > > - } > > + while (!QSIMPLEQ_EMPTY(&cpu->work_list)) { > > + wi = QSIMPLEQ_FIRST(&cpu->work_list); > > + QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node); > > qemu_mutex_unlock(&cpu->work_mutex); > > if (wi->exclusive) { > > /* Running work items outside the BQL avoids the following deadlock: > > diff --git a/cpus.c b/cpus.c > > index 5670c96bcf..af44027549 100644 > > --- a/cpus.c > > +++ b/cpus.c > > @@ -97,9 +97,19 @@ bool cpu_is_stopped(CPUState *cpu) > > return cpu->stopped || !runstate_is_running(); > > } > > > > +static inline bool cpu_work_list_empty(CPUState *cpu) > > +{ > > + bool ret; > > + > > + qemu_mutex_lock(&cpu->work_mutex); > > + ret = QSIMPLEQ_EMPTY(&cpu->work_list); > > + qemu_mutex_unlock(&cpu->work_mutex); > > + return ret; > > +} > > + > > static bool cpu_thread_is_idle(CPUState *cpu) > > { > > - if (cpu->stop || cpu->queued_work_first) { > > + if (cpu->stop || !cpu_work_list_empty(cpu)) { > > return false; > > } > > if (cpu_is_stopped(cpu)) { > > @@ -1498,7 +1508,7 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg) > > cpu = first_cpu; > > } > > > > - while (cpu && !cpu->queued_work_first && !cpu->exit_request) { > > + while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) { > > > > atomic_mb_set(&tcg_current_rr_cpu, cpu); > > current_cpu = cpu; > > diff --git a/hw/core/cpu.c b/hw/core/cpu.c > > index 5284d384fb..77703d62b7 100644 > > --- a/hw/core/cpu.c > > +++ b/hw/core/cpu.c > > @@ -368,6 +368,7 @@ static void cpu_common_initfn(Object *obj) > > cpu->nr_threads = 1; > > > > qemu_mutex_init(&cpu->work_mutex); > > + QSIMPLEQ_INIT(&cpu->work_list); > > QTAILQ_INIT(&cpu->breakpoints); > > QTAILQ_INIT(&cpu->watchpoints); > > > > diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h > > index 07f7698155..d78ff1d165 100644 > > --- a/include/hw/core/cpu.h > > +++ b/include/hw/core/cpu.h > > @@ -331,8 +331,8 @@ struct qemu_work_item; > > * @opaque: User data. > > * @mem_io_pc: Host Program Counter at which the memory was accessed. > > * @kvm_fd: vCPU file descriptor for KVM. > > - * @work_mutex: Lock to prevent multiple access to queued_work_*. > > - * @queued_work_first: First asynchronous work pending. > > + * @work_mutex: Lock to prevent multiple access to @work_list. > > + * @work_list: List of pending asynchronous work. > > * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes > > * to @trace_dstate). > > * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask). > > @@ -376,7 +376,7 @@ struct CPUState { > > sigjmp_buf jmp_env; > > > > QemuMutex work_mutex; > > - struct qemu_work_item *queued_work_first, *queued_work_last; > > + QSIMPLEQ_HEAD(, qemu_work_item) work_list; > > > > CPUAddressSpace *cpu_ases; > > int num_ases; > > >
diff --git a/cpus-common.c b/cpus-common.c index 55d5df8923..210fc7fc39 100644 --- a/cpus-common.c +++ b/cpus-common.c @@ -97,7 +97,7 @@ void cpu_list_remove(CPUState *cpu) } struct qemu_work_item { - struct qemu_work_item *next; + QSIMPLEQ_ENTRY(qemu_work_item) node; run_on_cpu_func func; run_on_cpu_data data; bool free, exclusive, done; @@ -106,13 +106,7 @@ struct qemu_work_item { static void queue_work_on_cpu(CPUState *cpu, struct qemu_work_item *wi) { qemu_mutex_lock(&cpu->work_mutex); - if (cpu->queued_work_first == NULL) { - cpu->queued_work_first = wi; - } else { - cpu->queued_work_last->next = wi; - } - cpu->queued_work_last = wi; - wi->next = NULL; + QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node); wi->done = false; qemu_mutex_unlock(&cpu->work_mutex); @@ -306,17 +300,14 @@ void process_queued_cpu_work(CPUState *cpu) { struct qemu_work_item *wi; - if (cpu->queued_work_first == NULL) { + qemu_mutex_lock(&cpu->work_mutex); + if (QSIMPLEQ_EMPTY(&cpu->work_list)) { + qemu_mutex_unlock(&cpu->work_mutex); return; } - - qemu_mutex_lock(&cpu->work_mutex); - while (cpu->queued_work_first != NULL) { - wi = cpu->queued_work_first; - cpu->queued_work_first = wi->next; - if (!cpu->queued_work_first) { - cpu->queued_work_last = NULL; - } + while (!QSIMPLEQ_EMPTY(&cpu->work_list)) { + wi = QSIMPLEQ_FIRST(&cpu->work_list); + QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node); qemu_mutex_unlock(&cpu->work_mutex); if (wi->exclusive) { /* Running work items outside the BQL avoids the following deadlock: diff --git a/cpus.c b/cpus.c index 5670c96bcf..af44027549 100644 --- a/cpus.c +++ b/cpus.c @@ -97,9 +97,19 @@ bool cpu_is_stopped(CPUState *cpu) return cpu->stopped || !runstate_is_running(); } +static inline bool cpu_work_list_empty(CPUState *cpu) +{ + bool ret; + + qemu_mutex_lock(&cpu->work_mutex); + ret = QSIMPLEQ_EMPTY(&cpu->work_list); + qemu_mutex_unlock(&cpu->work_mutex); + return ret; +} + static bool cpu_thread_is_idle(CPUState *cpu) { - if (cpu->stop || cpu->queued_work_first) { + if (cpu->stop || !cpu_work_list_empty(cpu)) { return false; } if (cpu_is_stopped(cpu)) { @@ -1498,7 +1508,7 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg) cpu = first_cpu; } - while (cpu && !cpu->queued_work_first && !cpu->exit_request) { + while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) { atomic_mb_set(&tcg_current_rr_cpu, cpu); current_cpu = cpu; diff --git a/hw/core/cpu.c b/hw/core/cpu.c index 5284d384fb..77703d62b7 100644 --- a/hw/core/cpu.c +++ b/hw/core/cpu.c @@ -368,6 +368,7 @@ static void cpu_common_initfn(Object *obj) cpu->nr_threads = 1; qemu_mutex_init(&cpu->work_mutex); + QSIMPLEQ_INIT(&cpu->work_list); QTAILQ_INIT(&cpu->breakpoints); QTAILQ_INIT(&cpu->watchpoints); diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h index 07f7698155..d78ff1d165 100644 --- a/include/hw/core/cpu.h +++ b/include/hw/core/cpu.h @@ -331,8 +331,8 @@ struct qemu_work_item; * @opaque: User data. * @mem_io_pc: Host Program Counter at which the memory was accessed. * @kvm_fd: vCPU file descriptor for KVM. - * @work_mutex: Lock to prevent multiple access to queued_work_*. - * @queued_work_first: First asynchronous work pending. + * @work_mutex: Lock to prevent multiple access to @work_list. + * @work_list: List of pending asynchronous work. * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes * to @trace_dstate). * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask). @@ -376,7 +376,7 @@ struct CPUState { sigjmp_buf jmp_env; QemuMutex work_mutex; - struct qemu_work_item *queued_work_first, *queued_work_last; + QSIMPLEQ_HEAD(, qemu_work_item) work_list; CPUAddressSpace *cpu_ases; int num_ases;