| Message ID | 20181025144644.15464-24-cota@braap.org |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,v4,01/71] cpu: convert queued work to a QSIMPLEQ | expand |
Emilio G. Cota <cota@braap.org> writes: > Cc: Cornelia Huck <cohuck@redhat.com> > Cc: Christian Borntraeger <borntraeger@de.ibm.com> > Cc: Alexander Graf <agraf@suse.de> > Cc: David Hildenbrand <david@redhat.com> > Cc: qemu-s390x@nongnu.org > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > Signed-off-by: Emilio G. Cota <cota@braap.org> > --- <snip> > > static unsigned s390_count_running_cpus(void) > @@ -340,10 +340,12 @@ unsigned int s390_cpu_halt(S390CPU *cpu) > CPUState *cs = CPU(cpu); > trace_cpu_halt(cs->cpu_index); > > - if (!cs->halted) { > - cs->halted = 1; > + cpu_mutex_lock(cs); > + if (!cpu_halted(cs)) { > + cpu_halted_set(cs, 1); > cs->exception_index = EXCP_HLT; > } > + cpu_mutex_unlock(cs); > > return s390_count_running_cpus(); > } > @@ -353,10 +355,12 @@ void s390_cpu_unhalt(S390CPU *cpu) > CPUState *cs = CPU(cpu); > trace_cpu_unhalt(cs->cpu_index); > > - if (cs->halted) { > - cs->halted = 0; > + cpu_mutex_lock(cs); > + if (cpu_halted(cs)) { > + cpu_halted_set(cs, 0); > cs->exception_index = -1; > } > + cpu_mutex_unlock(cs); I think this locking is superfluous as you already added locking when you introduced the helper. <snip> Otherwise: Reviewed-by: Alex Bennée <alex.bennee@linaro.org> -- Alex Bennée
On Wed, Oct 31, 2018 at 16:13:05 +0000, Alex Bennée wrote: > > @@ -353,10 +355,12 @@ void s390_cpu_unhalt(S390CPU *cpu) > > CPUState *cs = CPU(cpu); > > trace_cpu_unhalt(cs->cpu_index); > > > > - if (cs->halted) { > > - cs->halted = 0; > > + cpu_mutex_lock(cs); > > + if (cpu_halted(cs)) { > > + cpu_halted_set(cs, 0); > > cs->exception_index = -1; > > } > > + cpu_mutex_unlock(cs); > > I think this locking is superfluous as you already added locking when > you introduced the helper. It gives a small perf gain, since it avoids locking & unlocking twice in a row (cpu_halted and cpu_halted_set both take the lock if needed). > Otherwise: > > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Thanks! Emilio
Emilio G. Cota <cota@braap.org> writes: > On Wed, Oct 31, 2018 at 16:13:05 +0000, Alex Bennée wrote: >> > @@ -353,10 +355,12 @@ void s390_cpu_unhalt(S390CPU *cpu) >> > CPUState *cs = CPU(cpu); >> > trace_cpu_unhalt(cs->cpu_index); >> > >> > - if (cs->halted) { >> > - cs->halted = 0; >> > + cpu_mutex_lock(cs); >> > + if (cpu_halted(cs)) { >> > + cpu_halted_set(cs, 0); >> > cs->exception_index = -1; >> > } >> > + cpu_mutex_unlock(cs); >> >> I think this locking is superfluous as you already added locking when >> you introduced the helper. > > It gives a small perf gain, since it avoids locking & unlocking twice > in a row (cpu_halted and cpu_halted_set both take the lock if needed). Maybe a one line comment then above the first lock: /* lock outside cpu_halted(_set) to avoid bouncing */ Or some such..... > >> Otherwise: >> >> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > > Thanks! > > Emilio -- Alex Bennée
On Wed, 31 Oct 2018 16:56:54 +0000 Alex Bennée <alex.bennee@linaro.org> wrote: > Emilio G. Cota <cota@braap.org> writes: > > > On Wed, Oct 31, 2018 at 16:13:05 +0000, Alex Bennée wrote: > >> > @@ -353,10 +355,12 @@ void s390_cpu_unhalt(S390CPU *cpu) > >> > CPUState *cs = CPU(cpu); > >> > trace_cpu_unhalt(cs->cpu_index); > >> > > >> > - if (cs->halted) { > >> > - cs->halted = 0; > >> > + cpu_mutex_lock(cs); > >> > + if (cpu_halted(cs)) { > >> > + cpu_halted_set(cs, 0); > >> > cs->exception_index = -1; > >> > } > >> > + cpu_mutex_unlock(cs); > >> > >> I think this locking is superfluous as you already added locking when > >> you introduced the helper. > > > > It gives a small perf gain, since it avoids locking & unlocking twice > > in a row (cpu_halted and cpu_halted_set both take the lock if needed). > > Maybe a one line comment then above the first lock: > > /* lock outside cpu_halted(_set) to avoid bouncing */ > > Or some such..... Yes, please. Or introduce something like cpu_halted_flip(cs, new_state) where you could convert the above to if (cpu_halted_flip(cs, 0)) { /* cpu halted before */ cs_exception_index = -1; } Or is that actually an uncommon pattern? > > > > >> Otherwise: > >> > >> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > > > > Thanks! > > > > Emilio > > > -- > Alex Bennée
diff --git a/hw/intc/s390_flic.c b/hw/intc/s390_flic.c index 5f8168f0f0..bfb5cf1d07 100644 --- a/hw/intc/s390_flic.c +++ b/hw/intc/s390_flic.c @@ -198,7 +198,7 @@ static void qemu_s390_flic_notify(uint32_t type) } /* we always kick running CPUs for now, this is tricky */ - if (cs->halted) { + if (cpu_halted(cs)) { /* don't check for subclasses, CPUs double check when waking up */ if (type & FLIC_PENDING_SERVICE) { if (!(cpu->env.psw.mask & PSW_MASK_EXT)) { diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c index 18ba7f85a5..956d4e1d18 100644 --- a/target/s390x/cpu.c +++ b/target/s390x/cpu.c @@ -288,7 +288,7 @@ static void s390_cpu_initfn(Object *obj) CPUS390XState *env = &cpu->env; cs->env_ptr = env; - cs->halted = 1; + cpu_halted_set(cs, 1); cs->exception_index = EXCP_HLT; object_property_add(obj, "crash-information", "GuestPanicInformation", s390_cpu_get_crash_info_qom, NULL, NULL, NULL, NULL); @@ -313,8 +313,8 @@ static void s390_cpu_finalize(Object *obj) #if !defined(CONFIG_USER_ONLY) static bool disabled_wait(CPUState *cpu) { - return cpu->halted && !(S390_CPU(cpu)->env.psw.mask & - (PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK)); + return cpu_halted(cpu) && !(S390_CPU(cpu)->env.psw.mask & + (PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK)); } static unsigned s390_count_running_cpus(void) @@ -340,10 +340,12 @@ unsigned int s390_cpu_halt(S390CPU *cpu) CPUState *cs = CPU(cpu); trace_cpu_halt(cs->cpu_index); - if (!cs->halted) { - cs->halted = 1; + cpu_mutex_lock(cs); + if (!cpu_halted(cs)) { + cpu_halted_set(cs, 1); cs->exception_index = EXCP_HLT; } + cpu_mutex_unlock(cs); return s390_count_running_cpus(); } @@ -353,10 +355,12 @@ void s390_cpu_unhalt(S390CPU *cpu) CPUState *cs = CPU(cpu); trace_cpu_unhalt(cs->cpu_index); - if (cs->halted) { - cs->halted = 0; + cpu_mutex_lock(cs); + if (cpu_halted(cs)) { + cpu_halted_set(cs, 0); cs->exception_index = -1; } + cpu_mutex_unlock(cs); } unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu) diff --git a/target/s390x/excp_helper.c b/target/s390x/excp_helper.c index 2a33222f7e..d22c5b3ce5 100644 --- a/target/s390x/excp_helper.c +++ b/target/s390x/excp_helper.c @@ -461,7 +461,7 @@ try_deliver: if ((env->psw.mask & PSW_MASK_WAIT) || stopped) { /* don't trigger a cpu_loop_exit(), use an interrupt instead */ cpu_interrupt(CPU(cpu), CPU_INTERRUPT_HALT); - } else if (cs->halted) { + } else if (cpu_halted(cs)) { /* unhalt if we had a WAIT PSW somehwere in our injection chain */ s390_cpu_unhalt(cpu); } diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c index 2ebf26adfe..ffb52888c0 100644 --- a/target/s390x/kvm.c +++ b/target/s390x/kvm.c @@ -1005,7 +1005,7 @@ MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run) int kvm_arch_process_async_events(CPUState *cs) { - return cs->halted; + return cpu_halted(cs); } static int s390_kvm_irq_to_interrupt(struct kvm_s390_irq *irq, diff --git a/target/s390x/sigp.c b/target/s390x/sigp.c index c1f9245797..d410da797a 100644 --- a/target/s390x/sigp.c +++ b/target/s390x/sigp.c @@ -115,7 +115,7 @@ static void sigp_stop(CPUState *cs, run_on_cpu_data arg) } /* disabled wait - sleeping in user space */ - if (cs->halted) { + if (cpu_halted(cs)) { s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu); } else { /* execute the stop function */ @@ -131,7 +131,7 @@ static void sigp_stop_and_store_status(CPUState *cs, run_on_cpu_data arg) SigpInfo *si = arg.host_ptr; /* disabled wait - sleeping in user space */ - if (s390_cpu_get_state(cpu) == S390_CPU_STATE_OPERATING && cs->halted) { + if (s390_cpu_get_state(cpu) == S390_CPU_STATE_OPERATING && cpu_halted(cs)) { s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu); } @@ -313,7 +313,7 @@ static void sigp_cond_emergency(S390CPU *src_cpu, S390CPU *dst_cpu, } /* this looks racy, but these values are only used when STOPPED */ - idle = CPU(dst_cpu)->halted; + idle = cpu_halted(CPU(dst_cpu)); psw_addr = dst_cpu->env.psw.addr; psw_mask = dst_cpu->env.psw.mask; asn = si->param; @@ -347,7 +347,7 @@ static void sigp_sense_running(S390CPU *dst_cpu, SigpInfo *si) } /* If halted (which includes also STOPPED), it is not running */ - if (CPU(dst_cpu)->halted) { + if (cpu_halted(CPU(dst_cpu))) { si->cc = SIGP_CC_ORDER_CODE_ACCEPTED; } else { set_sigp_status(si, SIGP_STAT_NOT_RUNNING);